2. Exercise No. 10 ASSAY OF ASPIRIN TABLETS
Assay procedure: Residual alkalimetric with blank titration
Standard solution: 0.1N Sulfuric acid
Primary Standard: N sodium hydroxide
Indicator: Phenolphthalein TS
Chemical reactions:
(NH4)3PO4-12MoO3-H NaOH
11Na2MoO4 + (NH4)2 MoO4 + 12H2O
Endpoint color: Permanent pink color

3. Procedure
1. Weigh finely powder not less than tablets.
2. Transfer an accurately weighed amount of powdered tablets equivalent to 100mg Aspirin in a 500 mL Erlenmeyer flask to compute for the amount of sample equivalent to 100 mg of Aspirin. Use ratio and proportion
3. Add 15ml of neutralized alcohol and mix for five minutes.
4. Then add three drops of phenolphthalein and titrate with 0.1 N sodium Hydroxide until pink color is produced.
5. Add to the titrated solution a volume of 0.1 sodium hydroxide equal to that used in the titration plus 15 ml more, heat the mixture in a water bath for 15 minutes with frequent agitation using an air condenser. Remove the flask from the water bath and cool it quickly at room temperature.
6. Titrate with 0.1 N Sulfuric acid solution until the pink color disappears.
7. Perform the blank determination.

4. PREPARATION AND STANDARDIZATION OF TENTH-NORMAL(0.1) SILVER NITRATE
Exercise No. 11
Exercise No. 11
PREPARATION AND STANDARDIZATION OF TENTH-NORMAL(0.1) SILVER NITRATE

5. Assay procedure: Precipitation method
Exercise No. 11 PREPARATION AND STANDARDIZATION OF TENTH-NORMAL(0.1) SILVER NITRATE
Assay procedure: Precipitation method
Primary Standard: Sodium Chloride
Indicator: Eosin Y TS
Chemical reactions:
AgNO3 + HCl AgCl +HNO3
Endpoint color: Purplish color

6. Preparation and Standardization1.
Transfer 100 mg sodium chloride (dried at 110’C For 2 hrs) 2.
Dissolve in 5ml nitric acid + 50 ml methanol 3.
Add 3 drops Eosin Y TS.
STANDARDI ZATION
Weigh g Silver nitrate crystals
Add 250 ml distilled water
Titrate with silver nitrate solution.

7. Exercise 12 PREPARATION AND STANDARDIZATION OF TENTH-NORMAL(0
Exercise 12 PREPARATION AND STANDARDIZATION OF TENTH-NORMAL(0.1) SILVER NITRATE

8. Assay procedure: Direct titration under precipitation method
Exercise No. 12 PREPARATION AND STANDARDIZATION OF TENTH-NORMAL(0.1) AMMONIUM THIOCYANATE SOLUTION
Assay procedure: Direct titration under precipitation method
Standard solution: 0.1N Ammonium Thiocyanate
Indicator: Ferric alum
End point color: Red brown color solution
Reaction:
AgNO3 + NH4SCN AgSCN + NH4NO3

9. Schematic diagram: Procedure
15ml of 0.1N silver nitrate placed in erlenmayer flask
Dilute with 25ml distilled water
add 1ml nitric acid
1ml Ferric alum (indicator)
titrate with standard solution untill red-brown color appears

10. EXERCISE N0. 13 ASSAY OF SODIUM CHLORIDE CONTENT OF IODIZED SALT

11. EXERCISE N0. 13 ASSAY OF SODIUM CHLORIDE CONTENT OF IODIZED SALT
Assay procedure: Volumetric Residual Precipitation Method (Volhard Method)
Standard solution: O.1N Silver nitrate
Second Standard solution: 0.1N sodium thiocyanate
Indicator: Ferric alum
Analyte: Iodized salt solution
End point color: Red brown colored solution
Reaction:
NaCl + AgNO AgCl + NaNO3

12. 2ml ferric alum (indicator)
Schematic diagram 1.
300mg of iodized salt 2.
50ml distilled water 3.
50ml of 0.1 silver nitrate 4.
3ml nitric acid 5.
5ml nitrobenzene 6.
2ml ferric alum (indicator) 7.
Titrate with excess silver nitrate with standard solution until red brown color appears.

13. Exercise No. 14 ASSAY OF AMMONIUM BROMIDE

14. Exercise No. 14 ASSAY OF AMMONIUM BROMIDE
Assay procedure:Residual Precipitation Method Standard solution: 0.1N silver nitrate Second Standard Solution: 0.1 N Ammonium Thiocyanate Indicator: Ferric alum TS Analyte: Aspirin in neutralized alcohol End point color: Reddish-brown colored solution Reaction:

15. Schematic diagram 1. 300mg ammonium bromide
2. Dissolve in 50ml distilled water
3. 50ml 0.1N silver nitrate from buret
4. 2ml ferric alum (indicator)
5. 2ml nitric acid

16. Mrs. Junabeth Cervantez
Presented by:
DAGURO, Aprilyn
DOMALINA, Mae Realene
JUAN, Monicka
MACAYANAN, Romina R.
PASCUAL, Kris
Submitted to:
Mrs. Junabeth Cervantez