How will you test a gas which is liberated when hydrochloric acid reacts with an active metal?

How will you test a gas which is liberated when hydrochloric acid reacts with an active metal?

Hydrogen gas is produced when an active metal reacts with dilute hydrochloric acid, when a burning candle is brought near to hydrogen gas, a pop sound is heard due to the combustion of hydrogen to from water.

2H2(g) + O2(g) → 2H2O(g)