Question

how will you test for a gas which is liberated when hvl reacts with an active metal?

Answer 1

I think you typed wrong .

It would be HCl

When HCl reacts with a metal , H₂ gas is liberated .

Test for the gas

H₂ is a colourless and odourless gas which extinguishes a burning splinter with a pop sound .

Hope it helps :)

____________________________________________________________________

Answer 2

when Hcl reacts with any active metal then hydrogen gas is liberated .

TEST FOR HYDROGEN GAS IS :
when a burning matchstick is brought near this gas , the matchstick extinguishes with a pop sound indicating that hydrogen gas has released .