CBSE - Class 9 Science Atoms and Molecules Worksheet
1.
Write the chemical formulae of the following. (e) Calcium carbonate.
2.
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.
3.
Brief about the atomic mass unit?
4.
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?
5.
Calculate the molar mass of the following substances. (e) Nitric acid, $HNO_3$
6.
What are polyatomic ions? Give examples.
7.
Write the chemical formulae of the following. (a) Magnesium chloride
8.
Calculate the molar mass of the following substances. (a) Ethyne, $C_2H_2$
9.
Calculate the molar mass of the following substances. (b) Sulphur molecule, $S_8$
10.
Calculate the molar mass of the following substances. (c) Phosphorus molecule, $P_4$ (Atomic mass of phosphorus = 31)
11.
Calculate the molar mass of the following substances. (d) Hydrochloric acid, HCl
12.
Give the names of the elements present in the following compounds. (a) Quick lime
13.
Give the names of the elements present in the following compounds. (b) Hydrogen bromide
14.
Write the chemical formulae of the following. (b) Calcium oxide
15.
Write the chemical formulae of the following. (c) Copper nitrate
16.
Give the names of the elements present in the following compounds. (d) Potassium sulphate.
17.
Write the chemical formulae of the following. (d) Aluminium chloride
18.
Give the names of the elements present in the following compounds. (c) Baking powder
