Question

which gas is usually liberated when an acid reacts with a metal. how will you test that gas

Answer 1

H2 gas is liberated with brisk effervesnce.

Answer 2

hydrogen gas is liberated when an acid reacts with metal. to check the presence of hydrogen, capture some of this liberated gas in an inverted test tube and light a matchstick near its mouth, if it is hydrogen then you will hear popping sounds. hope this helped.