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

(N/A) When an active metal reacts with hydrochloric acid $(HCl)$,hydrogen gas $(H_2)$ is liberated.
To test for this gas,bring a burning candle or a matchstick near the mouth of the test tube or jar containing the gas.
The hydrogen gas burns with a characteristic '$pop$' sound,which confirms its presence.