ACIDS AND BASES

• Definition: aqueous solution of Hydrogen containing compounds

Name the following:

HCl H2SO4 H2SO3 H2S

Remember: H with an element: hydro_______ic acidH with polyatomic ion ending with –ate: _______ic acidH with polyatomic ion ending with –ite: _______ous acid

ACID

• Definition: aqueous solution of Hydrogen containing compounds

Name the following:

HCl hydrochloric acidH2SO4 sulfuric acidH2SO3 sulfurous acidH2S hydrosulfuric acid

ACID

Definition (for now): Contains the polyatomic ion OH-1

(hydroxide)

Name the following bases:

NaOH Ca(OH)2 Cu(OH)2 NH4OH

Follow ionic naming rules: name metal, name nonmetal, do NOT use prefixes! If the metal is a transition metal, use roman numeral for its charge

BASE

Definition (for now): Contains the polyatomic ion OH-1

(hydroxide)

Name the following bases:

NaOH sodium hydroxideCa(OH)2 calcium hydroxideCu(OH)2 copper (II) hydroxideNH4OH ammonium hydroxide

BASE

PROPERTIES OF ACIDS

• Ionize in water H3O+1

• Corrosive to metals and skin. (React with most metals to form hydrogen gas.)

• Taste sour (like lemons) • Frequently feel "sticky" • pH less than 7. • Neutralizes bases producing salt and water. • Electrolytes.

PROPERTIES OF BASES

• Ionize in water OH-

• Feel "slippery".• Taste bitter (like soap) • Electrolytes• pH greater than 7. • Neutralizes acids producing a salt and water.

INDICATORS

• Indicators are added to chemicals to determine the pH. They change colors in different pH’s.

• You need to memorize the indicators and colors!

ACID BASE INDICATORS

Type Acid Neutral Base

Red Litmus Red Red Blue

Blue Litmus Red Blue Blue

Phenolphthalein Clear Clear Hot pink

Bromothymol Blue Yellow Green Blue

• Concentration: amount of acid or base/amount of water or solution

• Strength: how well that particular acid or base ionizes (amount of H3O+1 or OH- )

• Strong acid/base: an acid/base that ionizes almost completely

• Weak acid/base: an acid/base that only slightly ionizes

STRENGTH VS. CONCENTRATION

ACIDS AND BASES

Strong WeakHCl H2SO4 HF HC2H3O2HBr HClO3 H2S H2SO3HI HClO4 HNO2 H3PO4HNO3

LIST OF STRONG AND WEAK ACIDS

Organic acids: end in –COOH, weak acid

Ex: vinegar CH3COOH

Strong WeakGroup I and II metals with hydroxides

NH3 and any non-group I or II hydroxide

LIST OF STRONG AND WEAK BASES

• Pure water ionize slightly according to this equation:

The product of molar concentrations of the ions is equal to a constant Kw. Formula:

Kw = 1 x 10-14 = [H3O+][OH-]

[ ] means concentration of (molarity)

IONIZATION OF WATER

−+ +↔+ OHOHOHOH 322

In a neutral solution:

In an acidic solution:

In a basic solution:

Basically this is saying there is more H3O+ in acidic solutions, more OH- in basic solutions. The concentrations of both are the same in neutral solutions

RELATIONSHIPS

73 10*1][][ −−+ == OHOH

][][ 3−+ > OHOH

][][ 3−+ < OHOH

pH: measure of [H3O+1] in a solution, measure of “acidity”

pOH: measure of [OH-1] in a solution, measure of “basicity”

PH AND POH

Neutral0 7 14

Acid Base

Neutral0 7 14

Base Acid

MORE ON PH

• A change in [H+] by a factor of 10 causes the pH to change by 1.

• Solution with a pH of 6 has 10x the [H+] as a solution with a pH of 7.

• What is the [H+] difference between pH of 1 and pH of 4?• 4-1= 3 that’s how many zero’s• Answer= pH 1 has 1000x more

1 42 53 6

IMPORTANT FORMULAS

]log[ 3+−= OHpH ]log[ 1−−= OHpOH

pHOH −+ = 10][ 3pOHOH −− = 10][ 1

14=+ pOHpH ]][[ 3−+= OHOHKW

• [H3O+] = 1.00 x 10-3M

• [H3O+] = 6.59 x 10-10M

• [H3O+] = 7.01 x 10-6M

FIND THE PH OF THE FOLLOWING:

• pH = 3

• pH = 6.61

• pH = 2.52

FIND THE [H3O+1]

• pOH = 2

• pOH = 1.26

• pOH = 4.98

FIND THE PH FOR THE FOLLOWING:

• [OH-] = 1.00 x 10-11M

• [OH-] = 2.64 x 10-13M

• [OH-] = 3.45 x 10-8M

FIND THE PH FOR THE FOLLOWING:

FIND THE [H3O+1]

[OH-] = 1.00 x 10-6M

[OH-] = 4.97 x 10-10M

[OH-] = 2.93 x 10-2M

FIND THE PH

•0.054M HCl

•0.178M NaOH

Theory Acid Definition

Base Definition

Arrhenius Releases H+1

into solutionReleases OH-1

into solutionBronsted-Lowery

Proton (H+1) donor

Proton (H+1) acceptor

TYPES OF ACIDS AND BASES

Neutralization, producing a salt and water

Generic Equation:

Salt: Ionic compound formed from the cation of a base and the anion of an acid

WHAT HAPPENS WHEN YOU MIX AN ARRHENIUS ACID WITH AN ARRHENIUS

BASE?

WaterSaltBaseAcid +→+

1. Sodium hydroxide and hydrochloric acid

2. Calcium hydroxide and sulfuric acid

3. Potassium hydroxide and nitric acid

Remember: these are double replacement reactions! You will switch the anions of the reactants.Don’t forget to balance charges when making the products! The subscripts might change! That’s okay!

NAME THE SALT PRODUCED AND WRITE THE BALANCED REACTION:

1. Sodium hydroxide and hydrochloric acid

NaOH + HCl NaCl + H2O

2. Calcium hydroxide and sulfuric acid

Ca(OH)2 + H2SO4 CaSO4 + 2H2O

3. Potassium hydroxide and nitric acid

KOH + HNO3 KNO3 + H2O

NAME THE SALT PRODUCED AND WRITE THE BALANCED REACTION:

REVIEW ACIDS AND BASES

• Watch this video by clicking the title

QUIZ TOPICS

• Acid/Base Properties• Acid/Base Definitions• Strong vs. Weak Acids and Bases (memorize them!)• Neutralization Reactions• pH/pOH Calculations

• Monoprotic acid: only has one ionizable hydrogenex: HCl, HBr, HC2H3O2, HNO3

• Polyprotic acid: more than one ionizable hydrogenex: H2SO4, H3PO4

• Amphoteric: substance that can act as an acid or as a baseex: H2O, NH3

DEFINITIONS

TITRATIONS

• An acid-base titration is a neutralization reaction that is performed in the lab in order to determine an unknown concentration of acid or base.

• Remember this: MAVA= MBVBM molarity (M)V volume (V)

TITRATIONS

• Endpoint: When the chosen indicator changes color and you stop the titration.

• Equivalence point: When the solution is completely neutralized. The reaction is complete. [H+] = [OH-]

• Indicator: weak acid or base and its conjugate ion; whose color changes in different pH’s

• Standard solution: solution of known concentration used as the titrant

• Carolina Biological Video

TITRATION TERMS

TITRATIONS

1) If it takes 54mL of 0.1M NaOH to neutralize 125mL of an HCl solution, what is the concentration of the HCl?

2) If it takes 25mL of 0.05M HCl to neutralize 345mL of NaOH solution, what is the concentration of NaOHsolution?

TITRATION CURVES

On the following slide you you will see 3 different curves.

The relationships are:Strong Acid titrated with Strong BaseWeak Acid titrated with Strong BaseStrong Acid titrated with Weak Base

Using those graphs compare the pH values of each substance as well as the equivalence points

MORE TITRATION CURVES

Strong base and weak acid curve

Strong acid and weak base curve

Strong acid and strong base curve