Which one of the following would you need to identify the gas that evolve when you heat NaOH solution with zinc metal?
(a) Red litmus solution
(b) Blue litmus solution
(c) A burning splinter/matchstick
(d) Lime water

AcademicChemistryNCERTClass 10

Correct Answer: (c) A burning splinter/matchstick 

Explanation: When a base like NaOH is treated with an active metal like Zn, it produces H2 gas. And the presence of the hydrogen gas can be tested by bringing a burning splinter/ matchstick near the gas produced. The gas will burn with a pop sound confirming the presence of hydrogen gas.

$Zn(s) + 2NaOH(aq) \rightarrow Na_2ZnO_2(aq) +H_2(g)$ 

Updated on 10-Oct-2022 12:46:41