Question

When a piece of aluminium is dropped in $HCl$ and in $NaOH$ separately, and a burning match is brought near them, pop sound is heard in case of .

• A. only HCl
• B. only NaOH
• C. both HCl and NaOH

Answer 1

The correct option is C both HCl and NaOH

Aluminium reacts with both dilute acids and bases and releases $H_2$ gas.
The reactions taking place are:

$2Al+6HCl\to 2AlC{l}_3+3H_2\uparrow$

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

Thus, in both the cases $H_2$ gas is released and a pop sound will be heard.