Question

$NaHC{O}_3$ solution is

• A. weakly basic
• B. weakly acidic
• C. strongly basic
• D. strongly acidic

Answer 1

The correct option is A weakly basic

The $NaHC{O}_3$ solution is weakly basic. It gives yellow colour with methyl orange, but no colour with phenolphthalein.

Theory:
Properties of $NaHC{O}_3$:

1. White crystalline solid, sparingly soluble in water.

2. The solution is alkaline in nature due to hydrolysis.
$NaHC{O}_3+H_{2}O\rightleftharpoons NaOH+H_{2}C{O}_3$
The solution is weakly basic.

It gives yellow colour with methyl orange but no colour with phenolphthalein.

3. On heating, it loses $C{O}_2$ and $H_{2}O$ forming $N{a}_{2}C{O}_3$
$2NaHC{O}_3\stackrel{\Delta }{⟶}N{a}_{2}C{O}_2+C{O}_2+H_{2}O$
$NaHC{O}_3$ is known as baking soda because it decomposes on heating to generate bubbles of
$C{O}_2$.