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 zinc is added in sodium solution sodium zincate $\left(N{a}_{2}Zn{O}_2\right)$ is formed along with hydrogen gas.

$2NaOH+Zn\to N{a}_{2}Zn{O}_2+H_2$

When burning splint is held near the evolved it continues burning with pop sound indicating evolution of Hydrogen gas.

Same metal i.e $Zn$ reacts with strong acid $H_{2}S{O}_4$ to give $ZnS{O}_4$

$Zn+H_{2}S{O}_4\to ZnS{O}_4+H_2\uparrow$