Question

2 mL of sodium hydroxide solution is added to a few pieces of granulated zinc metal taken in a test tube. When the contents are warmed, a gas evolves which is bubbled through a soap solution before testing. Write the equation of the chemical reaction involved and the test to detect the gas. Name the gas which will be evolved when the same metal reacts with dilute solution of a strong acid.

Answer 1

When sodium hydroxide is heated with Zinc granules - Sodium Zincate and hydrogen gas is evolved.

2NaOH(aq)+Zn(*)→Na2ZnO2(aq)+H2(g)↑

When burning splinter is brought near the mouth of the test tube, it burns with a pop sound. lf Zinc granules react with strong; acids (HCl or H2SO4) then again Hydrogen gas will be evolved.

Zn(*)+(dil)2HCl→ZnCl2+H2↑

Zn(*)+(dil)H2SO4→ZnSO4+H2↑