I. TITLE : a. Neutralization Titration

“Titration between NaOH solution 0,1N with oxalic acid as standar solution”

b. Aplication of Neutralization Titration

“Determining percent content of H2SO4 in accu zuur”

II. DATE : 22th November 2011, start at : 07:30 am-11:30 am

III. PURPOSE : a. Making and determining standardization of base solution.

b. Determining percent content of H2SO4 in Accu Zuur (Yuasa Merck).

IV. THEORY :

V. TOOLS AND MATERIALS

a. Burette

b. Conical Flask (Erlenmeyer)

c. Measuring Cylinder

d. Volumetric Flask

e. Volumetric pipette

f. Pro pipette

g. Beaker Glass

h. Pipette

i. Funnel

j. Analyst Balance

k. Picnometer

l. Spatula

m. Filter paper

n. Pipette

o. Aquadest

p. NaOH

q. Accu Zuur

r. Oxalic Acid

s. Methyl Orange Indicator

t. Phenolftalein Indicator

H2C2O4.2H2O 0, 6000 grams

taking place in volumetric flask 100 mLdissolving by aquadest until limitation markmixed well

Oxalate acid as standard solution

taking 10 mL of that solution using volumetric pipette (pour into Erlenmeyer 100 mL)pouring by aquadest 25 mL using graduated cylinderpouring by 3 drops of PP indicator

Oxalate acid as standard solution

titrate with NaOH solution until color of indicator is changedone 3 times repetationwritting down the scale of NaOH in the burrette in initial and final titrationcalculate the average concentration of NaOH

2NaOH + H2C2O4 Na2C2O4 + 2H2O

J

VI. PROCEDURE

Standarization of NaOH solution ± 0,1 N with oxalate acid as a standard solution

Accu Zuur

Pouring 2 ml in piknometer with volumetric pipetteClose the piknometer immediately Weight the piknometerDissolving with aquades in volumetric flask 100 mlKeeping it well until become cold

Weight the empty piknometer firstWriting the mass

Accu Zuur solution

Taking 10 ml into ErlenmeyerAdding several drops of methyl orange indicator

Accu Zuur solution + indicator

Titrate with NaOH 0,1 NRepeating until 3 timesCalculate the amount of H2SO4

Result

Determining Percentage of H2SO4 in Accu Zuur

VII.DATA

a. Titration of NaOH with Oxalic Acid

NoBurette Scale V NaOH

N NaOH (N) Titrator NoteBefore After (ml)

1

0

9,2

9,2

0,1034 Miftahul Izzati Laili

Using Burette

with accuracy ±0,05 mL

2 9,2 18,7 9,5 0,1002 Ninik Nigusti Ayu S.3 18,7 27,7 9 0,1057 Fitria Dwi Lestari

Naverage=0,1034+0,1002+0,1057

3

Naverage=0,1031Reaction: H2C2O4.2H2O(aq) + NaOH(aq)Na2C2O4(aq) + 4H2O(l)

b. Application of Acidy-Alkalimetry Titration

NoBurette Scale V NaOH

N NaOH (N) Titrator NoteBefore After (ml)

1

0

15

15

0,1546

Fitria Dwi Lestari

Using Burette

with accuracy ±0,05 mL

2 15 30,3 15,3 0,1577 Miftahul Izzati Laili3 30,3 45,3 15 0,1546 Ninik Nigusti Ayu S.

Naverage=0,1546+0,1577+0,1546

3

Naverage=0,1556Reaction:

H2SO4(aq) + NaOH(aq) Na2SO4(aq) + 2H2O(l)

VIII. ANALYSIS

Standardization of NaOH using oxalic acid

In the standardization of solution required a known concentration solution first. Solution

of known concentration is called standard solution. In the standardization of NaOH solution

required oxalic acid as standard solution. The first step is manufacture of standard solution of

H2C2O4 , we get 0.6000 g of H2C2O4 and then diluted in 100 mL of aquadest in volumetric flask,

this substance is soluble because of the polar.

The reaction is:

H2C2O4. 2H2O (s) + H2O (l) H2C2O4 (aq)

After making standard solution, this solution is taken 10 mL using volumetric pipette because

volumetric pipette has high standard accuracy and then it is poured in conical flask 100 mL and

added with 25 mL of aquadest and 3 drops of PP indicator. This solution is filtrated using NaOH

which have been put in burette until 0 scale. The purpose of addition indicator is to accelerate the

reaction during titration to achieve the end point that is marked by changing of color from

colorless to pink. The reaction that occur is :

H2C2O4 (aq) + NaOH (aq) 2H2O (l) + Na2C2O4(aq)

This titration is done 3 times and the volume of NaOH which is needed are 9.2 ml, 9.5 ml, and

9.0 ml.

In this volume, titration is stopped because it had reached end point of titration, from this

titration we can determine concentration of NaOH. From the calculation, we get the average

value of normality is 0,1031 N. we get this value from :

a. V NaOH x N NaOH = V C2H2O4.2H2O x N C2H2O4.2H2O0,0092 L x N NaOH = 0,01 L x 0,0952 NN NaOH = 0,1034 N

b. V NaOH x N NaOH = V C2H2O4.2H2O x N C2H2O4.2H2O0,0095 L x N NaOH = 0,01 L x 0,0952 NN NaOH = 0,1002 N

c. V NaOH x N NaOH = V C2H2O4.2H2O x N C2H2O4.2H2O0,0090 L x N NaOH = 0,01 L x 0,0952 NN NaOH = 0,1057 N

N average = 0,1034 N+0,1002 N+0,1057 N

3 = 0,1031 N

Reaction :

C2H2O4.2H2O (aq) + NaOH (aq) Na2C2O4 (aq) + 4H2O (l)

Determining percent content of H2SO4 in accu zuur

In this experiment, we have to determine the density of accu zuur first using piknometer. In the piknometer, already labeled the volume 25 ml. we need to know the mass of solution by weight the empty picnometer first and then weight the picnometer which had been filled with the accu zuur and calculate the mass. We can calculate the density directly from this formula :

ρ=mv

The density that we got, can be use to calculate the percentage of H2SO4 in accu zuurafter this titration done well. We use “Yuasa Accu Zuur” that had been titrated with NaOH which the concentration is known from the first experiment and methyl orange as indicator. Our data experiment show the volume of NaOH that we get sequencely are 15 ml, 15.3 ml and 15 ml. And then we have to determine the concentration of NaOH with the calculation below :

a.M eq H2SO4 = M eq NaOH

N H2SO4 = 0,1546 M eqml

= 0,1546 x 2 mmol= 0,3092 mmol

mmol = mgMr

0,3092 = x

49x = 15,1508 mg

in 100 ml solution

x = 15,1508 mg x 100= 1515,08 mg

= 1,51508 gram

Percentage H2SO4 = 1,515082,5614 x 100% = 59,15 %

b. N H2SO4 = 0,1577 M eqml

= 0,1577 x 2= 0,3154 mmol

mmol = mgMr

0,3154 = x

49x = 15,5446 mg

in 100 ml solution

x = 15,5446 mg x 100= 1554,46 mg= 1,55446 gram

Percentage H2SO4 = 1,554462,5614 x 100% = 60,34 %

c. N H2SO4 = 0,1557 M eqml

= 0,1557 x 2 mmol= 0,3114 mmol

mmol = mgMr

0,3114 = x

49x = 15,5286 mg

in 100 ml solution

x = 15,5286 mg x 100= 1552,86 mg= 1,55286 gram

Percentage H2SO4 = 1,552862,5614 x 100% = 59,57 %

% average =59,15 %+60,34 %+59,57 %

3

= 179,06 %

3 = 59,69 %

Thus, the percentage value of H2SO4 in accu zuur is 59,69 %

IX. DISCUSSION

a. Standardization of NaOH using oxalic acid as standard solution

when we did this experiment, we did not face any difficulties. We just have a little in determine the color changing of the analyte that the titrator can finish the titration. It is influence to the volume of NaOH that we need in this experiment for each repetation. So, we have to be more careful when read the burette scale and don’t forget to drop the indicator a moment before do the titration. Because it will influence the analyte and can change the result of the data.

b. Determining percent content of H2SO4 in accu zuur

when we do this experiment, we did some mistakes. We drop yhe indicator before the titration. Finally we repeat the procedure by make the solution again. And then we drop the indicator just a moment before we do the titration. When we still doing the titration, we were careless when read the scale of the burette while we can not determine the color changing. Because of our knowledge about pH trayek is poor so we don’t know the end of this titration.

X. CONCLUSION

From the result of experiment can be concluding that:

a. Standardization of NaOH using oxalic acid as standard solution

from the first experiment, we can know the concentration of NaOH, we can

standardize it using standard solution of oxalic acid using titration. Concentration of

oxalic acid is 0,0552 N and the average of NaOH concentration is 0,1031 N

b. Determining percent content of H2SO4 in accu zuur

using titration we can determine the percentage of H2SO4 in accu zuur from experiment we can know that percentage of H2SO4 in Yuasa Accu Zuur is 59,69%. It is gotten from weight percentage analysis :

% H2SO4 = mass of H 2 SO 4mass of sample x 100%

XI. Answer of Question :

1. Why in the manufacture of NaOH solution must use boiled water?

Answer:

In the manufacture of NaOH solution must use boiled water because it is not pure in

solution consisting of NaOH, but also contained Na2CO3 so that boiling water works to

remove CO2 contained in Na2CO3.

2. What is the difference between:

a. Standard primer solution and standard secondary solution?

b. Acidimetric and alkalimetri?

Answer:

a. In analytical chemistry, a standard solution is a solution containing a precisely known

concentration of an element or a substance i.e, a known weight of solute is dissolved to

make a specific volume. It is prepared using a standard substance, such as a primary

standard. Standard solutions are used to determine the concentrations of other

substances, such as solutions in titrations.

The difference between the primary standard solutions with secondary standard

solution are standard primer solution is a solution of known concentration for certain

and is used to determine the concentration of secondary standard solution, secondary

standard solution is a solution whose concentration has been determined accurately

through the standardization process.

b. Acidimetric i.e. involving base neutralization titration with acid of known

concentration.

Alkalimetri i.e. involving titration of neutralizing acid with a base of known

concentration.

3. Give reasons for the use of indicators in the titration of the above!

Answer: The use of indicators in the titration is useful to know when to stop adding

titrant because indicator will change color, and when there are changes

color is called the equivalence point and end point of titration.

XII. Refferences

Poedjiastuti, Sri., dkk. 2009. Panduan Praktikum Kimia Analitik I Dasar-dasar Kimia

Analitik. Surabaya: Jurusan Kimia FMIPA Unesa.

Day, R. A. 1991. Quantitative Analysis Sixth Edition. New Jersey: Prentice Hall.

Attachments :

Standardization of NaOH using oxalic acid as standard solution

Attachments :

Determining percent content of H2SO4 in accu zuur

Accu Zuur after titration

The color changing of accu zuur before titration and after titration