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Calcium hypochloriteFrom Wikipedia, the free encyclopedia
Calcium hypochlorite or Calcium oxychloride
Other names[hide]
Hypochlorous acid, calcium salt
Bleaching powder, Calcium oxychloride
Identifiers
CAS number 7778-54-3
ChemSpider 22912
EC number 231-908-7
UN number 1748
RTECS number NH3485000
Jmol-3D images Image 1
SMILES
[show]
InChI
[show]
Properties
Molecular formula Ca(ClO)2
Molar mass 142.98 g/mol
Appearance white/gray powder
Density 2.35 g/cm3 (20 °C)
Melting point100 °C
Boiling point175 °C, decomposes
Solubility inwater 21 g/100 mL, reacts
Solubility reacts in alcohol
Hazards
MSDS ICSC 0638
EU Index 017-012-00-7
EU classification Oxidant (O)
Corrosive (C)
Harmful (Xn)
Dangerous for the environment (N)
R-phrases R8, R22, R31, R34, R50
S-phrases (S1/2), S26, S36/37/39, S45,S61
NFPA 704
031
OX
Flash point Non-flammable
LD50 850 mg/kg (oral, rat)
Related compounds
Other anions Calcium chloride
Other cations Sodium hypochlorite
(verify) (what is: / ?)
Except where noted otherwise, data are given for materials in their standard
state (at 25 °C, 100 kPa)
Infobox references
Calcium hypochlorite is a chemical compound with formula Ca(Cl O )2. It is widely used for water treatment and as
a bleaching agent. This chemical is considered to be relatively stable and has greater available chlorine than sodium
hypochlorite (liquid bleach).
Contents
[hide]
1 Preparation
2 Properties
3 Uses
4 Safety
5 References
6 External links
Preparation[edit source | editbeta]
It is manufactured by the calcium process:
.
"Bleaching powder" is a mixture of calcium hypochlorite (Ca(OCl)2) and the
basic chloride CaCl2, H2O with some slaked lime, Ca(OH)2. [1]
Properties[edit source | editbeta]
Calcium hypochlorite is a yellow white solid which has a strong smell
of chlorine. It is not highly soluble in water and is more preferably used in soft
to medium-hard water. It has two forms: dry and hydrated. The hydrated form is
safer to handle.
Calcium hypochlorite reacts with carbon dioxide to form calcium carbonate and
release dichlorine monoxide:
.
A calcium hypochlorite solution is basic. This is due to
the hydrolysis performed by the hypochlorite ion, as hypochlorous
acid is weak, but calcium hydroxide is a strong base. As a result, the
hypochlorite ion is a strong conjugate base, and the calcium ion is a weak
conjugate acid:
ClO−
+ H2O → HClO + OH−
Similarly, calcium hypochlorite reacts with hydrochloric acid to
form calcium chloride, water and gaseous chlorine:
Ca(OCl)2 + 4 HCl → CaCl2 + 2 H2O + 2 Cl2
Uses[edit source | editbeta]
Calcium hypochlorite is used for the disinfection of drinking water
or swimming pool water. It is used as a sanitizer in outdoor
swimming pools in combination with acyanuric acid stabilizer,
which reduces the loss of chlorine due to ultraviolet radiation.
The calcium content hardens the water and tends to clog up
some filters; hence, some products containing calcium
hypochlorite also contain anti-scaling agents.
Calcium hypochlorite is an ingredient in bleaching powder, used
for bleaching cotton and linen. It is used in bathroom cleaners,
household disinfectant sprays, moss and algae removers, and
weedkillers.
In addition, calcium hypochlorite may be used to
manufacture chloroform.
Bleaching powder is used in the sugar industry for bleaching
sugar cane juice before its crystallization.
Safety[edit source | editbeta]
Calcium hypochlorite is best kept in a cool dry place away from
any organic material. It is known to undergo self heating and
rapid decomposition accompanied by the release of toxic
chlorine gas.[citation needed]
References[edit source | editbeta]
1. ̂ Pradyot Patnaik. Handbook of Inorganic Chemicals.
McGraw-Hill, 2002, ISBN 0-07-049439-8
External links[edit source | editbeta]
Chemical Land
V
T
E
Calcium
Categories:
Antiseptics
Bleaches
Hypochlorites
Calcium compounds
Oxidizing agents
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Sodium bicarbonateFrom Wikipedia, the free encyclopedia
Sodium bicarbonate
IUPAC name [hide]
Sodium hydrogen carbonate
Other names[hide]
Baking soda, bicarbonate of soda, nahcolite, sodium bicarbonate, sodium
hydrogencarbonate
Identifiers
CAS number 144-55-8
PubChem 516892
ChemSpider 8609
UNII 8MDF5V39QO
EC number 205-633-8
DrugBank DB01390
KEGG C12603
MeSH Sodium+bicarbonate
ChEBI CHEBI:32139
ChEMBL CHEMBL1353
RTECS number VZ0950000
ATC code B05 CB04 ,B05 XA02 ,QG04 BQ01
Beilstein Reference 4153970
Jmol-3D images Image 1
SMILES
[show]
InChI
[show]
Properties
Molecular formula NaHCO
3
Molar mass 84.007 g mol−1
Appearance White crystals
Odor odorless
Density 2.20 g cm−3[1]
Melting point50 °C, 323 K, 122 °F (decomposes to sodium
carbonate)
Solubility in water 9 g/100 mL
69 g/L (0 °C)[2]
96 g/L (20 °C)[3]
165 g/L (60 °C)[3]
236 g/L (100 °C)[2]
Solubility Soluble[vague] in acetone, insoluble inethanol
log P -0.82
Acidity (pKa) 10.329[4]
6.351 (carbonic acid)[4]
Refractive index (nD) 1.3344
Pharmacology
Routes of
administration
Intravenous, oral
Thermochemistry
Std enthalpy of
formation ΔfHo298
−948 kJ·mol−1[5]
Standard molar
entropy So298
102 J·mol−1·K−1[5]
Hazards
MSDS External MSDS
Main hazards Causes serious eye irritation
NFPA 704
0
10
LD50 4.22 g kg−
Related compounds
Other anions Sodium carbonate
Other cations Ammonium bicarbonate
Potassium bicarbonate
Related compounds Sodium bisulfate
Sodium hydrogen phosphate
(verify) (what is: / ?)
Except where noted otherwise, data are given for materials in their standard
state (at 25 °C, 100 kPa)
Infobox references
Sodium bicarbonate or sodium hydrogen carbonate is the chemical compound with the formula Na HCO 3. Sodium
bicarbonate is a white solid that is crystalline but often appears as a fine powder. It has a slightly salty, alkaline taste
resembling that of washing soda (sodium carbonate). The natural mineral form is nahcolite. It is a component of the
mineral natron and is found dissolved in many mineral springs. It is among the food additives encoded by European
Union, identified by the initials E 500. Since it has long been known and is widely used, the salt has many related
names such as baking soda, bread soda, cooking soda, and bicarbonate of soda. In colloquial usage, its name is
shortened to sodium bicarb, bicarb soda, or simply bicarb. The word saleratus, from Latin sal
æratus meaning aerated salt, was widely used in the 19th century for both sodium bicarbonate and potassium
bicarbonate. The term has now fallen out of common usage.
Contents
[hide]
1 History
2 Production
3 Mining
4 Chemistry
o 4.1 Thermal decomposition
5 Applications
o 5.1 Fire extinguisher
o 5.2 Cooking
o 5.3 Neutralization of acids and bases
o 5.4 Medical uses
o 5.5 Personal hygiene
o 5.6 Baking soda in sports
o 5.7 As a cleaning agent
o 5.8 As a biopesticide
o 5.9 Cattle feed supplement
o 5.10 Miscellaneous
6 In popular culture
o 6.1 Film
7 See also
8 References
9 Further reading
10 External links
History[edit source | editbeta]
The ancient Egyptians used natural deposits of natron, a mixture consisting mostly of sodium carbonate decahydrate,
and sodium bicarbonate. The natron was used as a cleansing agent like soap.
In 1791, a French chemist, Nicolas Leblanc, produced sodium carbonate, also known as soda ash. In 1846, two New
York bakers, John Dwight and Austin Church, established the first factory to develop baking soda from sodium
carbonate and carbon dioxide.[6]
This compound, referred to as saleratus, is mentioned in the famous novel Captains Courageous by Rudyard
Kipling as being used extensively in the 1800s in commercial fishing to prevent freshly-caught fish from spoiling.[7]
Production[edit source | editbeta]
Main article: Solvay process
NaHCO3 is mainly prepared by the Solvay process, which is the reaction of sodium chloride, ammonia, and carbon
dioxide in water. Calcium carbonate is used as the source of CO2 and the resultant calcium oxide is used to recover
the ammonia from the ammonium chloride. The product shows a low purity (75 %). Pure product is obtained from
sodium carbonate, water and carbon dioxide as reported in one of the following reactions. It is produced on the scale
of about 100,000 tonnes/year (as of 2001).[8]
NaHCO3 may be obtained by the reaction of carbon dioxide with an aqueous solution of sodium hydroxide. The initial
reaction produces sodium carbonate:
CO2 + 2 NaOH → Na2CO3 + H2O
Further addition of carbon dioxide produces sodium bicarbonate, which at
sufficiently high concentration will precipitate out of solution:
Na2CO3 + CO2 + H2O → 2 NaHCO3
Commercial quantities of baking soda are also produced by a similar
method: soda ash, mined in the form of the ore trona, is dissolved in water
and treated with carbon dioxide. Sodium bicarbonate precipitates as a
solid from this method:
Na2CO3 + CO2 + H2O → 2 NaHCO3
Mining[edit source | editbeta]
Naturally occurring deposits of nahcolite (NaHCO3) are found in
the Eocene-age (55.8–33.9 Ma) Green River Formation, Piceance
Basin in Colorado. Nahcolite was deposited as beds during periods of
high evaporation in the basin. It is commercially mined using in-situ
leach techniques involving dissolution of the nahcolite by heated
water that is pumped through the nahcolite beds and reconstituted
through a natural cooling crystallization process.
Chemistry[edit source | editbeta]
Sodium bicarbonate is an amphoteric compound. Aqueous solutions
are mildly alkaline due to the formation of carbonic
acid and hydroxide ion:
HCO−
3 + H2O → H
2CO
3 + OH−
Sodium bicarbonate can be used as a wash to remove any
acidic impurities from a "crude" liquid, producing a purer sample.
Reaction of sodium bicarbonate and anacid produce a salt and
carbonic acid, which readily decomposes to carbon dioxide and
water:
NaHCO3 + HCl → NaCl + H2CO3
H2CO3 → H2O + CO2(g)
Sodium bicarbonate reacts with acetic acid (found
in vinegar), producing sodium acetate, water,
and carbon dioxide:
NaHCO3 + CH3COOH → CH3COONa + H2O + CO2(g)
Sodium bicarbonate reacts with bases such
as sodium hydroxide to form carbonates:
NaHCO3 + NaOH → Na2CO3 + H2O
Sodium bicarbonate reacts with carboxyl
groups in proteins to give a
brisk effervescence from the formation of CO
2. This reaction is used to test for the
presence of carboxylic groups in protein.[citation
needed]
Thermal decomposition[edit
source | editbeta]
Above 50 °C, sodium bicarbonate gradually
decomposes into sodium carbonate, water
and carbon dioxide. The conversion is fast at
200 °C:[9]
2 NaHCO3 → Na2CO3 + H2O + CO2
Most bicarbonates undergo
this dehydration reaction. Further
heating converts the carbonate into
the oxide (at over 850°C):[9]
Na2CO3 → Na2O + CO2
These conversions are relevant to
the use of NaHCO3 as a fire-
suppression agent ("BC powder") in
some dry powder fire extinguishers.
Applications[edit
source | editbeta]
Fire extinguisher[edit
source | editbeta]
Sodium bicarbonate is used along
with sulphuric acid in some fire
extinguishers since the two react to
form carbon dioxide, an
extinguishing agent.
Cooking[edit
source | editbeta]
Main article: Leavening agent
Sodium bicarbonate, referred to as
"baking soda" is primarily used in
cooking (baking), as a leavening
agent. It reacts with acidic
components in batters, releasing
carbon dioxide, which causes
expansion of the batter and forms
the characteristic texture and grain
in pancakes, cakes, quick breads,
soda bread, and other baked and
fried foods. Acidic compounds that
induce this reaction
include phosphates, cream of
tartar, lemon
juice, yogurt, buttermilk, cocoa, vine
gar, etc. Sodium bicarbonate can
be substituted for baking
powder provided sufficient acid
reagent is also added to the recipe.
[10] Many forms of baking powder
contain sodium bicarbonate
combined with calcium acid
phosphate, sodium aluminum
sulphate [11] or cream of tartar.
Sodium bicarbonate was
sometimes used in cooking
vegetables, to make them softer,
although this has gone out of
fashion, as most people now prefer
firmer vegetables. However, it is still
used in Asian cuisine to tenderise
meats. Baking soda may react with
acids in food, including Vitamin
C (L-ascorbic acid). It is also used
in breadings such as for fried foods
to enhance crispness.
Heat causes sodium bicarbonate to
act as a raising agent by releasing
carbon dioxide when used in
baking. The carbon dioxide
production starts at temperatures
above 80 °C. Since the reaction
does not occur at room
temperature, mixtures (cake batter,
etc.) can be allowed to stand
without rising until they are heated
in the oven.
Neutralization of acids
and bases[edit
source | editbeta]
Many laboratories keep a bottle of
sodium bicarbonate powder within
easy reach, because sodium
bicarbonate is amphoteric, reacting
with acids and bases. Furthermore,
as it is relatively innocuous in most
situations, there is no harm in using
excess sodium bicarbonate. Also,
sodium bicarbonate powder may be
used to smother a small fire, as
heating of sodium bicarbonate
releases carbon dioxide.[12]
A wide variety of applications
follows from its neutralization
properties, including reducing the
spread of white phosphorus from
incendiary bullets inside an afflicted
soldier's wounds.[13][medical citation needed]
Medical uses[edit
source | editbeta]
Sodium bicarbonate mixed with
water can be used as an antacid to
treat acid indigestion and heartburn.
[14] It is used as the medicinal
ingredient in gripe water for infants.
[15]
Sodium bicarbonate has been
known to be used in first aid, in
treating scalding, to prevent
blistering and scarring with
instructions to cover the scalded
area with a liberal layer of sodium
bicarbonate and water paste and
seek medical assistance. This is
due to the endothermic reaction
that occurs between sodium
bicarbonate and water and sodium
bicarbonate's mild antiseptic
properties[16][medical citation needed]
Intravenous sodium bicarbonate is
an aqueous solution that is
sometimes used for cases
of acidosis, or when there are
insufficient sodium or bicarbonate
ions in the blood.[17] In cases of
respiratory acidosis, the infused
bicarbonate ion drives the carbonic
acid/bicarbonate buffer of plasma to
the left and, thus, raises the pH. It is
for this reason that sodium
bicarbonate is used in medically
supervised cardiopulmonary
resuscitation. Infusion of
bicarbonate is indicated only when
the blood pH is markedly (<7.1–7.0)
low.[18]
Oral sodium bicarbonate has been
shown to slow progression to end
stage renal disease in individuals
with stage 4 chronic kidney
disease and metabolic
acidosis (plasma sodium
bicarbonate levels 16-20meq/L). [19]
It is used as well for treatment
of hyperkalemia. Since sodium
bicarbonate can cause alkalosis, it
is sometimes used to treat aspirin
overdoses. Aspirin requires an
acidic environment for proper
absorption, and the basic
environment diminishes aspirin
absorption in the case of an
overdose. Sodium bicarbonate has
also been used in the treatment
of tricyclic antidepressant overdose.
[20] It can also be applied topically as
a paste, with three parts baking
soda to one part water, to relieve
some kinds of insect bites and
stings (as well as accompanying
swelling).[21]
Adverse reactions to the
administration of sodium
bicarbonate can include metabolic
alkalosis, edema due to sodium
overload, congestive heart
failure, hyperosmolar syndrome,
hypervolemic hypernatremia,
and hypertension due to increased
sodium. In patients consuming a
high-calcium or dairy-rich
diet, calcium supplements, or
calcium-containing antacids such
as calcium carbonate (e.g., Tums),
the use of sodium bicarbonate can
cause milk-alkali syndrome, which
can result in metastatic
calcification, kidney stones, and
kidney failure.
Sodium bicarbonate can be used to
treat an allergic reaction to plants
such as poison -ivy -oak or -
sumac to relieve some of the
associated itching.[22]
Bicarbonate of soda can also be
useful in removing splinters from
the skin.[23]
Personal hygiene[edit
source | editbeta]
Toothpaste containing sodium
bicarbonate has in several studies
shown to have a better whitening[24]
[24][25][26] and plaque removal effect[27]
[28] than toothpastes without it.
Sodium bicarbonate is also used as
an ingredient in some
mouthwashes. It works as a
mechanical cleanser on the teeth
and gums, neutralizes the
production of acid in the mouth and
also acts as anantiseptic to help
prevent infections.[citation needed]
Sodium bicarbonate in combination
with other ingredients can be used
to make a dry or wet deodorant.[29]
[30] It may also be used as a
shampoo.[31]
Sodium bicarbonate may be used
as a buffering agent, combined with
table salt, when creating a solution
for nasal irrigation.[32]
Baking soda in
sports[edit
source | editbeta]
Small amounts of sodium
bicarbonate have been shown to be
useful as a supplement for athletes
in speed-based events, like middle
distance running, lasting from about
one to seven minutes.[33][34] But
overdose is a serious risk because
sodium bicarbonate is slightly
toxic[35] and in particular
gastrointestinal irritation is of
concern.[34] Additionally this practice
causes a significant increase in
dietary sodium.
As a cleaning agent[edit
source | editbeta]
A paste from baking soda can be
very effective when used in
cleaning and scrubbing.[36] For
cleaning aluminium objects, the use
of sodium bicarbonate is
discouraged as it attacks the thin
unreactive protective oxide layer of
this otherwise very reactive metal.
A solution in warm water will
remove the tarnish from silver when
the silver is in contact with a piece
of aluminium foil [37] [38] A paste of
sodium bicarbonate and water is
useful in removing surface rust as
the rust forms a water soluble
compound when in a concentrated
alkaline solution.[39] Cold water
should be used as hot water
solutions can corrode steel.[40]
Baking soda is commonly added to
washing machines as a
replacement for softener and to
remove odors from clothes. Sodium
bicarbonate is also effective in
removing heavy tea and coffee
stains from cups when diluted with
warm water.
During the Manhattan Project to
develop the atomic bomb in the
early 1940s, many scientists
investigated the toxic properties of
uranium. They found that uranium
oxides stick very well to cotton
cloth, but did not wash out with
soap or laundry detergent. The
uranium would wash out with a 2%
solution of sodium bicarbonate
(baking soda). Clothing can
become contaminated with
depleted uranium (DU) dust and
normal laundering will not remove
it. Those at risk of DU dust
exposure should have their clothing
washed with baking soda (about 6
ounces (170g) of baking soda in 2
gallons (7.5l) of water).[41]
As a biopesticide[edit
source | editbeta]
Sodium bicarbonate can be an
effective way of controlling fungus
growth,[42] and in the United States
is registered by the Environmental
Protection Agency as
a biopesticide.[43]
Cattle feed
supplement[edit
source | editbeta]
Sodium bicarbonate is sold as a
cattle feed supplement, in particular
as a buffering agent for the rumen.
[44]
Miscellaneous[edit
source | editbeta]
Sodium bicarbonate can be used to
extinguish small grease or electrical
fires by being thrown over the fire.
[12] However, it should not be
applied to fires in deep fryers, as it
may cause the grease to splatter.
[12]Sodium bicarbonate is used in
BC dry chemical fire
extinguishers as an alternative to
the more corrosive ammonium
phosphate in ABC extinguishers.
The alkali nature of sodium
bicarbonate makes it the only dry
chemical agent, besides Purple-K,
that was used in large-scale fire
suppression systems installed in
commercial kitchens. Because it
can act as an alkali, the agent has a
mild saponification effect on hot
grease, which forms a smothering
soapy foam. Dry chemicals have
since fallen out of favor for kitchen
fires, as they have no cooling effect
compared to the extremely effective
wet chemical agents specifically
designed for such hazards.[citation
needed]
Sodium bicarbonate is used in a
process for removing paint and
corrosion called sodablasting; the
process is particularly suitable for
cleaning aluminium panels which
can be distorted by other types of
abrasive. It can be administered to
pools, spas, and garden ponds to
raise pH levels.[45] It has
weak disinfectant properties,[46][47] an
d it may be an
effective fungicide against some
organisms.[48]
Since it acts as a neutralizing
agent, it can be used to absorb
odors that are caused by strong
acids.[citation needed] Because baking
soda will absorb musty smells, it
has become a reliable method for
used-book sellers when making
books less malodorous.[49]
Sodium bicarbonate is also used as
required to increase Total Alkinity
level in swimming pools and
aquarium freshwater fish tanks.
Some alternative practitioners have
promoted baking soda as
a cancer cure, which the American
Cancer Society has warned against
due to both its unproven
effectiveness and potential danger
in use. [50]
In popular culture[edit
source | editbeta]
Film[edit source | editbeta]
Sodium bicarbonate, as
'bicarbonate of soda', was a
frequent source of punch lines
for Groucho Marx in Marx
brothers movies. In Duck Soup,
Marx plays the leader of a nation at
war. In one scene, he receives a
message from the battlefield that
his general is reporting a gas
attack, and Groucho tells his aide,
"Tell him to take a teaspoonful of
bicarbonate of soda and a half a
glass of water."[51] In A Night at the
Opera, Groucho's character
addresses the opening night crowd
at an opera by saying of the lead
tenor, "Signor Lassparri comes from
a very famous family. His mother
was a well-known bass singer. His
father was the first man to stuff
spaghetti with bicarbonate of soda,
thus causing and curing indigestion
at the same time."[52]
See also[edit
source | editbeta]
Carbonic acid
Baking powder
List of minerals
Nahcolite
Natron
Natrona (disambiguation)
Trona
References[edit
source | editbeta]
1. ̂ "Physical Constants of
Inorganic
Compounds". CRC
Handbook, p. 4-85.
2. ^ a b "Aqueous solubility of
inorganic compounds at
various
temperatures". CRC
Handbook, p. 8-116.
3. ^ a b "Sodium Bicarbonate".
UNEP Publications.
4. ^ a b Goldberg, Robert N.;
Kishore, Nand; Lennen,
Rebecca M.
"Thermodynamic quantities
for the ionization reactions
of buffers in water". CRC
Handbook. pp. 7–13.
5. ^ a b Zumdahl, Steven S.
(2009). Chemical Principles
6th Ed. Houghton Mifflin
Company. p. A23. ISBN 0-
618-94690-X.
6. ̂ "Company History".
Church & Dwight Co.
7. ̂ Rudyard Kipling. Captains
Courageous. p. 25
8. ̂ Holleman, A. F.; Wiberg,
E. "Inorganic Chemistry"
Academic Press: San
Diego, 2001. ISBN 0-12-
352651-5.
9. ^ a b "Decomposition of
Carbonates". General
Chemistry Online.
10. ̂ Radiation Cookery Book
45th Edition, Radiation
Group Sales Ltd 1954
11. ̂ "Glossary Ingredients".
Cooking.com.
12. ^ a b c "Arm & Hammer
Baking Soda – Basics –
The Magic Of Arm &
Hammer Baking Soda".
Armhammer.com.
Retrieved 2009-07-30.
13. ̂ "White Phosphorus".
GlobalSecurity.org.
Retrieved 2007-09-26.
14. ̂ "Sodium Bicarbonate".
Jackson Siegelbaum
Gastroenterology. 1998.
15. ̂ List of ingredients – Life
Brand Gripe Water
16. ̂ "New Scientist Last Word
Blog: Soda soother". New
Scientist. Retrieved 22
September 2011.
17. ̂ "Sodium Bicarbonate
Intravenous
Infusion". Consumer
Medicine Information.
Better Health Channel.
2004-07-13.
18. ̂ "Respiratory Acidosis:
Treatment & Medication".
emedicine.
19. ̂ de Brito-Ashurst I,
Varagunam M, Raftery MJ,
Yaqoob MM. (Sep 2009).
"Bicarbonate
supplementation slows
progression of CKD and
improves nutritional
status.". J Am Soc
Nephrol. 20 (9): 2075–
84.PMID 19608703.
20. ̂ Knudsen, K;
Abrahamsson, J (Apr
1997). "Epinephrine and
sodium bicarbonate
independently and
additively increase survival
in experimental amitriptyline
poisoning". Critical Care
Medicine 25 (4): 669–
74. doi:10.1097/00003246-
199704000-00019. ISSN 00
90-3493. PMID 9142034.
21. ̂ "Insect bites and stings:
First aid". Mayo Clinic.
2008-01-15.
22. ̂ What is Sodium
Bicarbonate Used For?.
Virtuowl.com. Retrieved on
2010-09-24.
23. ̂ [1]
24. ^ a b Kleber, CJ; Moore, MH,
Nelson, BJ (1998).
"Laboratory assessment of
tooth whitening by sodium
bicarbonate
dentifrices.". The Journal of
clinical dentistry 9 (3): 72–
5. PMID 10518866.
25. ̂ Koertge, TE; Brooks, CN,
Sarbin, AG, Powers, D,
Gunsolley, JC (1998). "A
longitudinal comparison of
tooth whitening resulting
from dentifrice use.". The
Journal of clinical
dentistry 9 (3): 67–
71. PMID 10518865.
26. ̂ Yankell, SL; Emling, RC,
Petrone, ME, Rustogi, K,
Volpe, AR, DeVizio, W,
Chaknis, P, Proskin, HM
(1999). "A six-week clinical
efficacy study of four
commercially available
dentifrices for the removal
of extrinsic tooth
stain.". The Journal of
clinical dentistry 10 (3 Spec
No): 115–
8.PMID 10825858.
27. ̂ Mankodi, S; Berkowitz, H,
Durbin, K, Nelson, B
(1998). "Evaluation of the
effects of brushing on the
removal of dental
plaque.". The Journal of
clinical dentistry 9 (3): 57–
60. PMID 10518862.
28. ̂ Putt, MS; Milleman, KR,
Ghassemi, A, Vorwerk, LM,
Hooper, WJ, Soparkar, PM,
Winston, AE, Proskin, HM
(2008). "Enhancement of
plaque removal efficacy by
tooth brushing with baking
soda dentifrices: results of
five clinical studies.". The
Journal of clinical
dentistry 19 (4): 111–
9. PMID 19278079.
29. ̂ Lamb, John Henderson
(31 May 1946). "Sodium
Bicarbonate: An Excellent
Deodorant". The Journal of
Investigative
Dermatology 7 (3): 131–
133. doi:10.1038/jid.1946.1
3.
30. ̂ "Bicarb soda: natural
body deodorant". Retrieved
5 May 2012.
31. ̂ Bouchard, Mallory (2010-
05-04). "A Green and
Healthy Beauty Secret:
Going Shampoo-
Free". Four Green Steps.
32. ̂ Ralph B. Metson,
M.D., The Harvard Medical
School Guide to Healing
Your Sinues (McGraw Hill
2005), at p. 68.
33. ̂ Bee, Peta (2008-08-
16). "Is bicarbonate of soda
a performance enhancing
drug". The Times (London).
Retrieved 2010-05-23.
34. ^ a b Ergogenic Aids. U.
Retrieved on 2011-09-11.
35. ̂ Baking soda overdose –
All Information. Umm.edu
(2009-10-19). Retrieved on
2010-09-24.
36. ̂ "Arm & Hammer Baking
Soda – Basics – The Magic
Of Arm & Hammer Baking
Soda". Armhammer.com.
Retrieved 2009-07-30.
37. ̂ Eco Silver Polishing.
instructables.com (2006-12-
20). Retrieved on 2011-10-
07.
38. ̂ "Put a Shine on It".
scifun.chem.wisc.edu.
Retrieved 2011-03-06.
39. ̂ Catherine E. Housecroft;
Alan G. Sharpe (2008).
"Chapter 22: d-block metal
chemistry: the first row
elements". Inorganic
Chemistry, 3rd Edition.
Pearson. p. 716. ISBN 978-
0-13-175553-6.
40. ̂ .http://
www.sciencelab.com/
msds.php?
msdsId=9927263
41. ̂ Orcutt,
JA. "Scientist". Pharmacolo
gy and Toxicology of
Uranium Compounds.
McGraw-Hill. Retrieved 21
March 2012.
42. ̂ Potassium bicarbonate
(073508) and Sodium
bicarbonate (073505) Fact
Sheet United States
Environmental Protection
Agency. Updated 17
February 2011. Retrieved
25 November 2011.
43. ̂ Registered Biopesticides
04/29/02 United States
Environmental Protection
Agency. Updated 29 March
2002. Retrieved 25
November 2011.
44. ̂ "Acidosis Health Warning
for Livestock Farmers".
Retrieved 5 May 2012.
45. ̂ "Arm & Hammer Baking
Soda – Basics – The Magic
Of Arm & Hammer Baking
Soda". Armhammer.com.
Retrieved 2009-07-30.
46. ̂ Malik, Ys; Goyal, Sm
(May 2006). "Virucidal
efficacy of sodium
bicarbonate on a food
contact surface against
feline calicivirus, a
norovirus
surrogate". International
Journal of Food
Microbiology 109 (1–2):
160–3. do
i:10.1016/j.ijfoodmicro.2005
.08.033. ISSN 0168-1605.
PMID 16540196.
47. ̂ William A. Rutala, Susan
L. Barbee, Newman C.
Aguiar, Mark D. Sobsey,
David J. Weber, (2000).
"Antimicrobial Activity of
Home Disinfectants and
Natural Products Against
Potential Human
Pathogens".Infection
Control and Hospital
Epidemiology (The
University of Chicago Press
on behalf of The Society for
Healthcare Epidemiology of
America)21 (1): 33–
38. doi:10.1086/501694. P
MID 10656352.
48. ̂ Zamani, M; Sharifi,
Tehrani, A; Ali, Abadi, Aa
(2007). "Evaluation of
antifungal activity of
carbonate and bicarbonate
salts alone or in
combination with biocontrol
agents in control of citrus
green
mold".Communications in
agricultural and applied
biological sciences 72 (4):
773–7. PMID 18396809.
49. ̂ Gail Altman (2006-05-
22). "Book Repair for
BookThinkers: How To
Remove Odors From
Books". The
BookThinker (69).
50. ̂ "Sodium Bicarbonate".
51. ̂ http://www.imdb.com/
title/tt0023969/trivia?tab=qt
52. ̂ http://www.imdb.com/
title/tt0026778/trivia?
tab=qt&ref_=tt_trv_qu
Further reading[edit
source | editbeta]
Bishop, D; Edge, J; Davis, C;
Goodman, C (May 2004).
"Induced metabolic alkalosis
affects muscle metabolism and
repeated-sprint
ability". Medicine and science
in sports and exercise 36 (5):
807–
13
.doi:10.1249/01.MSS.0000126
392.20025.17. ISSN 0195-
9131. PMID 15126714.
David R. Lide, ed. (2003). CRC
Handbook of Chemistry and
Physics (84th ed.). Boca
Raton, FL: CRC
Press. ISBN 0-8493-0484-9.
External links[edit
source | editbeta]
Wikimedia Commons has
media related to: Sodium
bicarbonate
Wikibooks Cookbook has a
recipe/module on
Baking soda
International Chemical Safety
Card 1044
Differences between Baking
Soda and Baking Powder
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Sodium hydroxideFrom Wikipedia, the free encyclopedia
Sodium hydroxide
Preferred IUPAC name [hide]
Sodium hydroxide[1]
Systematic name [hide]
Sodium oxidanide[citation needed]
Other names[hide]
Caustic soda
Lye [2][3]
Ascarite
White caustic
Sodium hydrate[1]
Identifiers
CAS number 1310-73-2
PubChem 14798
ChemSpider 14114
UNII 55X04QC32I
EC number 215-185-5
UN number 1823
KEGG D01169
MeSH Sodium+Hydroxide
ChEBI CHEBI:32145
RTECS number WB4900000
Gmelin Reference 68430
Jmol-3D images Image 1
SMILES
[show]
InChI
[show]
Properties
Molecular formula NaOH
Molar mass 39.9971 g mol-1
Appearance White, waxy, opaque crystals
Odor odorless
Density 2.13 g/cm3
Melting point318 °C, 591 K, 604 °F
Boiling point1388 °C, 1661 K, 2530 °F
Solubility in water 111 g/100 mL (at 20 °C)
Solubility inmethanol 23.8 g/100 mL
Solubility in ethanol <<13.9 g/100 mL
Vapor pressure <2.4 kPa (at 20 °C)
Acidity (pKa) 13
Refractive index(nD) 1.3576
Hazards
MSDS External MSDS
GHS pictograms
EU Index 011-002-00-6
EU classification
C
R-phrases R35
S-phrases (S1/2), S26, S37/39, S45
NFPA 704
0
3
1
ALK
Related compounds
Other anions Sodium hydrosulfide
Other cations Caesium hydroxide
Lithium hydroxide
Potassium hydroxide
Rubidium hydroxide
(verify) (what is: / ?)
Except where noted otherwise, data are given for materials in
their standard state (at 25 °C, 100 kPa)
Infobox references
Sodium hydroxide, also known as caustic soda,[2][3] or lye, is an inorganic compound with the chemical
formula NaOH (also written as NaHO). It is a white solid, and is a highly caustic metallic base and alkali salt. It is
available in pellets, flakes, granules, and as a 50% saturated solution.[citation needed]
Sodium hydroxide is soluble in water, ethanol and methanol. This alkali is deliquescent and readily
absorbs moisture and carbon dioxide in air.
Sodium hydroxide is used in many industries, mostly as a strong chemical base in the manufacture
of pulp and paper, textiles, drinking water, soaps and detergentsand as a drain cleaner. Worldwide production in
2004 was approximately 60 million tonnes, while demand was 51 million tonnes.[4]
Contents
[hide]
1 Properties
o 1.1 Physical properties
o 1.2 Chemical properties
1.2.1 Reaction with acids
1.2.2 Reaction with acidic oxides
1.2.3 Reaction with amphoteric metals and oxides
1.2.4 Precipitant
1.2.5 Saponification
2 Production
3 Uses
o 3.1 Chemical pulping
o 3.2 Tissue digestion
o 3.3 Dissolving amphoteric metals and compounds
o 3.4 Esterification and transesterification reagent
o 3.5 Food preparation
o 3.6 Cleaning agent
o 3.7 Historical uses
o 3.8 Experimental
4 Safety
5 See also
6 References
7 Bibliography
8 External links
Properties[edit source | edit beta ]
Physical properties[edit source | edit beta ]
Pure sodium hydroxide is a whitish solid, sold in pellets, flakes, and granular form, as well as in solution. It is highly
soluble in water, with a lower solubility in ethanol and methanol, but is insoluble in ether and other non-polar solvents.
Similar to the hydration of sulfuric acid, dissolution of solid sodium hydroxide in water is a highly exothermic reaction
in which a large amount of heat is liberated, posing a threat to safety through the possibility of splashing. The
resulting solution is usually colourless and odorless with slippery feeling upon contact in common with other alkalis.
Chemical properties[edit source | edit beta ]
Reaction with acids[edit source | edit beta ]
Sodium hydroxide reacts with protic acids to produce water and the corresponding salts. For example, when sodium
hydroxide reacts with hydrochloric acid, sodium chloride is formed:
NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l)
In general, such neutralization reactions are represented by one simple net ionic equation:
OH − (aq) + H + (aq) → H2O(l)
This type of reaction with a strong acid releases heat, and hence is exothermic. Such acid-base
reactions can also be used for titrations. However, sodium hydroxide is not used as a primary
standard because it is hygroscopic and absorbs carbon dioxide from air.
Reaction with acidic oxides[edit source | edit beta ]
Sodium hydroxide also reacts with acidic oxides, such as sulfur dioxide. Such reactions are often used to
"scrub" harmful acidic gases (like SO2 and H2S) produced in the burning of coal and thus prevent their
release into the atmosphere. For example,
2 NaOH + CO2 → Na2CO3 + H2O
Reaction with amphoteric metals and oxides[edit source | edit beta ]
Sodium hydroxide slowly reacts with glass to form sodium silicate. Because of this, glass joints
and stopcocks exposed to sodium hydroxide have a tendency to "freeze". Flasks and glass-
lined chemical reactors are damaged by long exposure to hot sodium hydroxide, which also frosts the
glass. Sodium hydroxide does not attack iron since iron does not have amphoteric properties (i.e., it
only dissolves in acid, not base). A few transition metals, however, may react vigorously with sodium
hydroxide.
In 1986, an aluminium road tanker in the UK was mistakenly used to transport 25% sodium hydroxide
solution,[5] causing pressurization of the contents and damage to the tanker. The pressurization was
due to the hydrogen gas which is produced in the reaction between sodium hydroxide and aluminium:
2 Al + 2 NaOH + 6 H2O → 2 Na[Al(OH)4] + 3 H2
Precipitant[edit source | edit beta ]
Unlike sodium hydroxide, the hydroxides of most transition metals are insoluble, and therefore
sodium hydroxide can be used to precipitate transition metal hydroxides. The following colours are
observed: Blue-copper, Green-Iron(II), Yellow/Brown-Iron(III). Zinc and Lead salts dissolve in
excess sodium hydroxide to give a clear solution of Na2ZnO2 or Na2PbO2.
Aluminium hydroxide is used as a gelatinous flocculant to filter out particulate matter in water
treatment. Aluminium hydroxide is prepared at the treatment plant fromaluminium sulfate by
reacting it with sodium hydroxide.
Al2(SO4)3 + 6 NaOH → 2 Al(OH)3 + 3 Na2SO4
Saponification[edit source | edit beta ]
Sodium hydroxide can be used for the base-driven hydrolysis of esters (as
in saponification), amides and alkyl halides. However, the limited solubility of sodium
hydroxide in organic solvents means that the more soluble potassium hydroxide (KOH) is
often preferred.
Production[edit source | edit beta ]
Sodium hydroxide is industrially produced as a 50% solution by variations of the
electrolytic chloralkali process. Chlorine gas is also produced in this process. Solid sodium
hydroxide is obtained from this solution by the evaporation of water. Solid sodium hydroxide
is most commonly sold as flakes, prills, and cast blocks.[4]
In 2004, world production was estimated at 60 million dry metric tonnes of sodium hydroxide,
and demand was estimated at 51 million tonnes.[4] In 1998, total world production was around
45 million tonnes. North America and Asia collectively contributed around 14 million tonnes,
while Europe produced around 10 million tonnes. In the United States, the major producer of
sodium hydroxide is the Dow Chemical Company, which has annual production around
3.7 million tonnes from sites at Freeport, Texas, and Plaquemine, Louisiana. Other major US
producers include OxyChem, PPG, Olin, Pioneer Companies, Inc. (PIONA, which was
purchased by Olin), and Formosa. All of these companies use the chloralkali process.[6]
Historically sodium hydroxide is produced by treating sodium carbonate with calcium
hydroxide in a metathesis reaction. (Sodium hydroxide is soluble while calcium carbonate is
not.) This process was called causticizing.[7]
Ca(OH)2(aq) + Na2CO3(s) → CaCO3↓ + 2 NaOH(aq)
This process was superseded by the Solvay process in the late 19th century, which was
in turn supplanted by the chloralkali process which we use today.
Sodium hydroxide is also produced by combining pure sodium metal with water. The
byproducts are hydrogen gas and heat, often resulting in a flame, making this a common
demonstration of the reactivity of alkali metals in academic environments; however, it is
not commercially viable, as the isolation of sodium metal is typically performed by
reduction or electrolysis of sodium compounds including sodium hydroxide.
Uses[edit source | edit beta ]
Canister of sodium hydroxide.
Sodium hydroxide is the principal strong base used in the chemical industry. In bulk it is
most often handled as an aqueous solution, since solutions are cheaper and easier to
handle. Sodium hydroxide, a strong base, is responsible for most of these applications.
Another strong base such as potassium hydroxide is likely to yield positive results as
well.
Overall 56% of sodium hydroxide produced is used by the chemical industry, with 25%
of the same total used by the paper industry. Sodium hydroxide is also used for the
manufacture of sodium salts and detergents, for pH regulation, and for organic
synthesis. It is used in the Bayer process of aluminium production.[4]
Sodium hydroxide is used in many scenarios where it is desirable to increase the
alkalinity of a mixture, or to neutralize acids.
For example, sodium hydroxide is used as an additive in drilling mud to
increase alkalinity in bentonite mud systems, to increase the mud viscosity, and to
neutralise anyacid gas (such as hydrogen sulfide and carbon dioxide) which may be
encountered in the geological formation as drilling progresses.
In the same industry, poor quality crude oil can be treated with sodium hydroxide to
remove sulfurous impurities in a process known as caustic washing. As above, sodium
hydroxide reacts with weak acids such as hydrogen sulfide and mercaptans to give the
non-volatile sodium salts which can be removed. The waste which is formed is toxic and
difficult to deal with, and the process is banned in many countries because of this. In
2006, Trafigura used the process and then dumped the waste in Africa.[8][9]
See also: hydrodesulfurization
Chemical pulping[edit source | edit beta ]
Main article: Pulp (paper)
Sodium hydroxide is also widely used in pulping of wood for making paper or
regenerated fibers. Along with sodium sulfide, sodium hydroxide is a key component of
the white liquor solution used to separatelignin from cellulose fibers in the kraft process.
It also plays a key role in several later stages of the process of bleaching the brown
pulp resulting from the pulping process. These stages
include oxygendelignification, oxidative extraction, and simple extraction, all of which
require a strong alkaline environment with a pH > 10.5 at the end of the stages.
Tissue digestion[edit source | edit beta ]
In a similar fashion, sodium hydroxide is used to digest tissues, such as in a process
that was used with farm animals at one time. This process involved placing a carcass
into a sealed chamber, then adding a mixture of sodium hydroxide and water (which
breaks the chemical bonds that keep the flesh intact). This eventually turns the body into
a liquid with coffee-like appearance,[10][11] and the only solid that remains are bone hulls,
which could be crushed between one's fingertips.[12] Sodium hydroxide is frequently used
in the process of decomposing roadkill dumped in landfills by animal disposal
contractors.[11] Due to its low cost and availability, it has been used to dispose of corpses
by criminals. In Mexico, a man who worked for different drug cartels admitted disposing
over 300 bodies with it.[13]
Dissolving amphoteric metals and compounds[edit
source | edit beta ]
Strong bases attack aluminium. Sodium hydroxide reacts with aluminium and water to
release hydrogen gas. The aluminium takes the oxygen atom from sodium hydroxide,
which in turn takes the oxygen atom from the water, and releases the two hydrogen
atoms, The reaction thus produces hydrogen gas and sodium aluminate. In this reaction,
sodium hydroxide acts as an agent to make the solution alkaline, which aluminium can
dissolve in. This reaction can be useful in etching, removing anodizing, or converting a
polished surface to a satin-like finish, but without further passivation such
as anodizing or alodining the surface may become degraded, either under normal use or
in severe atmospheric conditions.
In the Bayer process, sodium hydroxide is used in the refining of alumina containing
ores (bauxite) to produce alumina (aluminium oxide) which is the raw material used to
produce aluminium metal via theelectrolytic Hall-Héroult process. Since the alumina
is amphoteric, it dissolves in the sodium hydroxide, leaving impurities less soluble at
high pH such as iron oxides behind in the form of a highly alkaline red mud.
See also: Ajka alumina plant accident
Other amphoteric metals are zinc and lead which dissolve in concentrated sodium
hydroxide solutions to give sodium zincate and sodium plumbate respectively.
Esterification and transesterification reagent[edit
source | edit beta ]
Sodium hydroxide is traditionally used in soap making (cold
process soap, saponification).[14] It was made in the nineteenth century for a hard
surface rather than liquid product because it was easier to store and transport.
For the manufacture of biodiesel, sodium hydroxide is used as a catalyst for
the transesterification of methanol and triglycerides. This only works
with anhydrous sodium hydroxide, because combined with water the fat would turn
into soap, which would be tainted with methanol. It is used more often than potassium
hydroxide because it is cheaper and a smaller quantity is needed.
Food preparation[edit source | edit beta ]
Food uses of sodium hydroxide include washing or chemical peeling
of fruits and vegetables, chocolate and cocoa processing, caramel
coloring production, poultry scalding, soft drink processing, and thickening ice
cream. Olives are often soaked in sodium hydroxide for
softening; Pretzels and German lye rolls are glazed with a sodium hydroxide solution
before baking to make them crisp. Owing to the difficulty in obtaining food grade sodium
hydroxide in small quantities for home use, sodium carbonate is often used in place of
sodium hydroxide.[15]
Specific foods processed with sodium hydroxide include:
The Pinoy or Filipino dessert (kakanin) called kutsinta uses a bit of lye water to help
give the rice flour batter a jelly like consistency.
A similar process is also used in the kakanin known as pitsi-pitsi or pichi-pichi (pit-
chi-pit-chi) except that the mixture uses grated cassava instead of rice flour.
The Scandinavian delicacy known as lutefisk (from lutfisk, "lye fish").
Hominy is dried maize (corn) kernels reconstituted by soaking in lye-water. These
expand considerably in size and may be further processed by frying to make corn
nuts or by drying and grinding to make grits.Nixtamal is similar, but uses calcium
hydroxide instead of sodium hydroxide.
Sodium hydroxide is also the chemical that causes gelling of egg whites in the
production of Century eggs.
German pretzels are poached in a boiling sodium carbonate solution or cold sodium
hydroxide solution before baking, which contributes to their unique crust.
Lye-water is an essential ingredient in the crust of the traditional baked Chinese
moon cakes.
Most yellow coloured Chinese noodles are made with lye-water but are commonly
mistaken for containing egg.
Some methods of preparing olives involve subjecting them to a lye-based brine.[16]
Cleaning agent[edit source | edit beta ]
Main article: Cleaning agent
Sodium hydroxide is frequently used as an industrial cleaning agent where it is often
called "caustic". It is added to water, heated, and then used to clean process equipment,
storage tanks, etc. It can dissolvegrease, oils, fats and protein based deposits. It is also
used for cleaning waste discharge pipes under sinks and drains in domestic
properties. Surfactants can be added to the sodium hydroxide solution in order to
stabilize dissolved substances and thus prevent redeposition. A sodium hydroxide soak
solution is used as a powerful degreaser on stainless steel and glass bakeware. It is
also a common ingredient in oven cleaners.
A common use of sodium hydroxide is in the production of parts washer detergents.
Parts washer detergents based on sodium hydroxide are some of the most aggressive
parts washer cleaning chemicals. The sodium hydroxide based detergent include
surfactants, rust inhibitors and defoamers. A parts washer heats water and the detergent
in a closed cabinet and then sprays the heated sodium hydroxide and hot water at
pressure against dirty parts for degreasing applications. Sodium hydroxide used in this
manner replaced many solvent based systems in the early 1990s[citation
needed] when trichloroethane was outlawed by the Montreal Protocol. Water and sodium
hydroxide detergent based parts washers are considered to be an environmental
improvement over the solvent based cleaning methods.
Hardware stores grade sodium hydroxide to be used as a type of drain cleaners.
Paint stripping with caustic soda
Sodium hydroxide is used in the home as a type of drain opener to unblock clogged
drains, usually in the form of a dry crystal or as a thick liquid gel. The alkali
dissolves greases to produce water soluble products. It
also hydrolyzes the proteins such as those found in hair which may block water pipes.
These reactions are sped by the heat generated when sodium hydroxide and the other
chemical components of the cleaner dissolve in water. Such alkaline drain cleaners and
their acidic versions are highly corrosive and should be handled with great caution.
Sodium hydroxide is used in some relaxers to straighten hair. However, because of the
high incidence and intensity of chemical burns, manufacturers of chemical relaxers use
other alkaline chemicals in preparations available to average consumers. Sodium
hydroxide relaxers are still available, but they are used mostly by professionals.
A solution of sodium hydroxide in water was traditionally used as the most common
paint stripper on wooden objects. Its use has become less common, because it can
damage the wood surface, raising the grain and staining the colour.
Historical uses[edit source | edit beta ]
Sodium hydroxide has been used for detection of carbon monoxide poisoning, with
blood samples of such patients turning to a vermilion color upon the addition of a few
drops of sodium hydroxide.[17] Today, carbon monoxide poisoning can be detected
by CO oximetry.
Experimental[edit source | edit beta ]
Sodium hydroxide is also being used experimentally in a new technology to create
synthetic gasoline.[18]
Sodium hydroxide test for flavonoids
Safety[edit source | edit beta ]
Chemical burns caused by sodium hydroxide solution photographed 44 hours after exposure.
Like other corrosive acids and alkalis, drops of sodium hydroxide solutions can
decompose proteins and lipids in skin, eyes or other living tissues via amide
hydrolysisand ester hydrolysis which consequently causes chemical burns and may
induce permanent blindness if it contacts eyes.[2][3] Solid alkali may also express its
corrosive nature if there is water so protective equipment such as rubber gloves, safety
clothing and eye protection should always be used when handling the material or its
solutions.
Moreover, dissolution of sodium hydroxide is highly exothermic, and the resulting heat
may cause heat burns or ignite flammables. It also produces heat when reacted with
acids.
The standard first aid measures for alkali spills on the skin is, as for other corrosives,
irrigation with large quantities of water. Washing is continued for at least ten to fifteen
minutes.
Sodium hydroxide is corrosive to several metals, like aluminium which reacts with the
alkali to produce flammable hydrogen gas on contact:[19]
2 Al + 2 NaOH + 2 H2O → 3 H2 + 2 NaAlO2
2 Al + 6 NaOH + x H2O → 3 H2 + 2 Na3AlO3 + x H2O
2 Al + 2 NaOH + 6 H2O → 3 H2 + 2 NaAl(OH)4
Sodium hydroxide is also mildly corrosive to glass, which can cause
damage to glazing or freezing of ground glass joints. Careful storage is
needed.
See also[edit source | edit beta ]
HAZMAT Class 8 Corrosive Substances
Common chemicals
List of elemental cleaning agents
References[edit source | edit beta ]
1. ^ a b "Sodium Hydroxide - Compound Summary". Retrieved June 12,
2012.
2. ^ a b c "Material Safety Datasheet".
3. ^ a b c "Material Safety Datasheet 2".
4. ^ a b c d Cetin Kurt, Jürgen Bittner (2005), "Sodium
Hydroxide",Ullmann's Encyclopedia of Industrial Chemistry,
Weinheim: Wiley-VCH,doi:10.1002/14356007.a24_345.pub2
5. ̂ Stamell, Jim (2001), EXCEL HSC Chemistry, Pascal Press,
p. 199,ISBN 978-1-74125-299-6
6. ̂ Kirk-Othmer Encyclopedia of Chemical Technology 5th edition
(online, account needed), John Wiley & Sons. Accessed November
21, 2005.
7. ̂ Deming, Horace G. (1925). General Chemistry: An Elementary
Survey Emphasizing Industrial Applications of Fundamental
Principles (2nd ed.). New York: John Wiley & Sons, Inc. p. 452.
8. ̂ Sample, Ian (16 September 2009). "Trafigura case: toxic slop left
behind by caustic washing". The Guardian. Retrieved 2009-09-17.
9. ̂ "Trafigura knew of waste dangers". BBC Newsnight. 16
September 2009. Retrieved 2009-09-17.
10. ̂ Ayres, Chris (27 February 2010) Clean green finish that sends a
loved one down the drain Times Online. Retrieved 2013-02-20.
11. ^ a b Thacker, H. Leon; Kastner, Justin (August 2004). Carcass
Disposal: A Comprehensive Review. Chapter 6. National
Agricultural Biosecurity Center, Kansas State University, 2004.
Retrieved 2010-03-08
12. ̂ Roach, Mary (2004). Stiff: The Curious Lives of Human Cadavers,
New York: W.W. Norton & Company. ISBN 0-393-32482-6.
13. ̂ William Booth (January 27, 2009). "'Stewmaker' Stirs Horror in
Mexico". Washington Post.
14. ̂ Morfit, Campbell (1856). A treatise on chemistry applied to the
manufacture of soap and candles. Parry and McMillan.
15. ̂ "Hominy without Lye". National Center for Home Food
Preservation.
16. ̂ "Olives: Safe Methods for Home Pickling (application/pdf
Object)".ucanr.org. 2010 [last update]. Retrieved January 22, 2012.
17. ̂ Page 168 in: The Detection of poisons and strong drugs. Author:
Wilhelm Autenrieth. Publisher: P. Blakiston's son & Company, 1909.
18. ̂ Andrew Hough (18 October 2012). "British engineers produce
amazing 'petrol from air' technology". The Telegraph. Retrieved 21
October 2012.
19. ̂ "aluminium_water_hydrogen.pdf (application/pdf
Object)".www1.eere.energy.gov. 2008 [last update]. Retrieved
January 15, 2013.
Bibliography[edit source | edit beta ]
Euro Chlor-How is chlorine made? Chlorine Online
Greenwood, Norman N. ; Earnshaw, Alan (1997). Chemistry of the
Elements (2nd ed.). Butterworth–Heinemann. ISBN 0080379419.
Heaton, A. (1996) An Introduction to Industrial Chemistry, 3rd edition,
New York:Blackie. ISBN 0-7514-0272-9.
External links[edit source | edit beta ]
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European Union Risk Assessment Report
Production by brine electrolysis
Titration of acids with sodium hydroxide; freeware for data analysis,
simulation of curves and pH calculation
Caustic soda production in continuous causticising plant by lime
soda process
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