Question

Which of the following metal gives hydrogen gas, when heated with hot concentrated alkali.

• A. Cu
• B. Ag
• C. Zn
• D. Ni

Answer 1

Answer: (C)

Zn

Answer 2

$Zn + \underset{\text{Conc.}}{NaOH} \rightarrow \underset{\text{Sodium zincate}}{Na_{2}ZnO_{2}} + \underset{\text{Hydrogen}}{H_{2}}$

Thus in this reaction hydrogen gas is produced when zinc is treated with concentrated NaOH.