Question

What happens when a base reacts with a metal?

• A. Brisk effervescence occurs.
• B. Milkiness is observed.
• C. Gas formed burns with a pop sound.
• D. A loud sound is produced.

Answer 1

The correct option is C

Gas formed burns with a pop sound.

When alkali (base) reacts with metal, it produces salt and hydrogen gas. Hydrogen burns with a pop sound.

Alkali + Metal $\to$ Salt + Hydrogen

Example: Sodium hydroxide gives hydrogen gas and sodium zincate when it reacts with zinc metal.

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

Sodium aluminate and hydrogen gas are formed when sodium hydroxide reacts with aluminium metal.

$2NaOH+2Al+2H_{2}O\to 2NaAl{O}_2+3H_2$