Question

Describe a test (other than electrolysis) to prove that hydrochloric acid contains hydrogen.

Answer 1

Test: Take dilute hydrochloric acid in a test tube and add a piece of active metal like Zinc (Zn) to it.

Observation: A colourless and odourless gas is evolved with effervescence. When a burning splinter is brought near the mouth of the test tube, the gas burns with a 'pop' sound, proving it is Hydrogen gas.

Equation: \[\ce{Zn + 2HCl -> ZnCl2 + H2 ^}\]