A chemical equation is a statement that describes a chemical change in terms of:

1. Symbols and formulae
2. Energy
3. Number of atoms
4. Colours

Balancing a chemical equation is based on:

1. Law of conservation of mass
2. Mass of reactants and products
3. Symbols and formulae
4. None of the above

When lead acetate solution is added to potassium iodide solution a precipitate is formed which is:

1. Red
2. Yellow
3. White
4. Black

This gas has a rotten egg smell:

1. Ammonia
2. Hydrogen
3. Hydrogen sulphide
4. Oxygen