CBSE - Class 9 Science Atoms and Molecules Worksheet
EXERCISES
1.
Calculate the molar mass of the following substances. (a) Ethyne, $C_2H_2$
2.
Give the names of the elements present in the following compounds. (d) Potassium sulphate.
3.
What are polyatomic ions? Give examples.
4.
Write the chemical formulae of the following. (e) Calcium carbonate.
5.
Calculate the molar mass of the following substances. (e) Nitric acid, $HNO_3$
6.
Calculate the molar mass of the following substances. (d) Hydrochloric acid, HCl
7.
Calculate the molar mass of the following substances. (c) Phosphorus molecule, $P_4$ (Atomic mass of phosphorus = 31)
8.
Calculate the molar mass of the following substances. (b) Sulphur molecule, $S_8$
9.
Write the chemical formulae of the following. (c) Copper nitrate
10.
Give the names of the elements present in the following compounds. (c) Baking powder
11.
Write the chemical formulae of the following. (d) Aluminium chloride
12.
Give the names of the elements present in the following compounds. (b) Hydrogen bromide
13.
Write the chemical formulae of the following. (a) Magnesium chloride
14.
Give the names of the elements present in the following compounds. (a) Quick lime
15.
Write the chemical formulae of the following. (b) Calcium oxide
16.
When 3.0 g of carbon is burnt in 8.00 g oxygen, 11.00 g of carbon dioxide is produced. What mass of carbon dioxide will be formed when 3.00 g of carbon is burnt in 50.00 g of oxygen? Which law of chemical combination will govern your answer?
17.
A 0.24 g sample of compound of oxygen and boron was found by analysis to contain 0.096 g of boron and 0.144 g of oxygen. Calculate the percentage composition of the compound by weight.
