DPP -11C11

Empirical & Molecular Formula

1. A compound contains 4.07 % hydrogen, 24.27 % carbon and 71.65 % chlorine. Its molar mass is 98.96 g. What are its empirical and molecular formulas?

2. Determine the empirical formula of an oxide of iron, which has 69.9 % iron and 30.1 % oxygen by mass.

3. A welding fuel gas contains carbon and hydrogen only. Burning a small sample of it in oxygen gives 3.38 g carbon dioxide, 0.690 g of water and no other products. MM=26. Find the molecular formula of Welding fuel.

4. Butyric acid contains only C,H and O. A 4.24 g sample of butyric acid is completely burned. It gives 8.45 g of carbon dioxide (CO₂) and 3.46 g of water. The vapour density of butyric acid was determined by experiment to be 44. What is the molecular formula?

5. A compound contains 6.32 % hydrogen, 75.92 % carbon and 17.76 % Nitrogen. Its vapour density is 39.5. What are its empirical and molecular formulas?

6. A Organic compound contain carbon, Hydrogen and Oxygen. In the compound C = 38.71 %, H = 9.67 % and rest is Oxygen. Find the empirical formula of the compound.

7. In a compounds C, H and N are present in the ratio of 9:1:3.5 by weight. molecular weight of the compound is 108, then find the molecular formula of the compound.