You can test for hydrogen gas by putting a burning splinter near the gas. The splinter will gives out a 'pop' sound (mini explosion) if it is hydrogen gas
A splint is lit and held near the opening of the tube, then the stopper is removed to expose the splint to the gas. If the gas is flammable, the mixture ignites. This test is most commonly used to identify hydrogen, which extinguishes with a distinctive 'squeaky pop' sound.
