Identify the gas evolved

1. sodium propionate is heated with soda lime
2. a few crystals of KNO3 are heated in a hard glass test tube
3. conc. HCl is made to react with manganese dioxide

1) When sodium propionate is heated with soda lime ethane gas is produced.

2) Oxygen is evolved when potassium nitrate is heated.

3) Chlorine is released when hydrochloric acid reacts with manganese dioxide.