1. Revision section

2. Problem (1) Deduce the empirical formula for each of the following compounds: Deduce the empirical formula for each of the following compounds: - %C = 42.6, %H = 3.5, %N = 20 - %C = 60.6, %H = 4.8, %N = 11.8,%S= 9

3. Problem (2) A sample of aspirin was determined to be 60% C, 4.4% H, and 35.6% O. the molecular weight is 180. What is the molecular formula for aspirin? A sample of aspirin was determined to be 60% C, 4.4% H, and 35.6% O. the molecular weight is 180. What is the molecular formula for aspirin?

4. Problem (3) Ten grams of an aromatic acid gave on combustion the following data: 13.006 g of CO 2, 2.214 g of H 2 O, 2.27 g of NO 2, and 3.152 g of SO 2. Its molecular weight was found to be 203. Find its molecular structure and formula. Ten grams of an aromatic acid gave on combustion the following data: 13.006 g of CO 2, 2.214 g of H 2 O, 2.27 g of NO 2, and 3.152 g of SO 2. Its molecular weight was found to be 203. Find its molecular structure and formula.

5. Acid value The mass of potassium hydroxide (KOH) in milligrams that is required to neutralize one gram of chemical substance. The mass of potassium hydroxide (KOH) in milligrams that is required to neutralize one gram of chemical substance.potassium hydroxidemilligramschemical substancepotassium hydroxidemilligramschemical substance

6. Acid value Acid value = (A x N x 56.1)/W Where: - Where: - A: ml of 0.1N KOH consumed for sample. N: Normality of KOH W: Weight in gm of the sample.

7. Problem (4) 50 gm of organic oil is tested for the acid value using KOH solution of concentration 0.1 N. the consumed volume of KOH till the end point was found to be 10 ml. what is the acid value of that oil? 50 gm of organic oil is tested for the acid value using KOH solution of concentration 0.1 N. the consumed volume of KOH till the end point was found to be 10 ml. what is the acid value of that oil?

8. Problem (5) 28 gm of KOH was dissolved in 500 ml distilled water in order to prepare KOH solution to be used in the determination of 20 gm of an organic substance. The consumed volume of KOH was found to be 30 ml. what is the acid value of that organic substance? 28 gm of KOH was dissolved in 500 ml distilled water in order to prepare KOH solution to be used in the determination of 20 gm of an organic substance. The consumed volume of KOH was found to be 30 ml. what is the acid value of that organic substance?