Question

$NaOH$ is formed according to reaction,
$2Na+\frac{1}{2}{O}_2⟶Na{O}_2$
$N{a}_{2}O+H_{2}O⟶2NaOH$
To make $4$ g $NaOH$, $Na$ required is :

• A. $2.3$ g
• B. $2.8$ g
• C. $3.0$ g
• D. $2.0$ g

Answer 1

The correct option is A $2.3$ g

The reactions are given below:

$2Na+\frac{1}{2}{O}_2⟶N{a}_{2}O$
$N{a}_{2}O+H_{2}O⟶2NaOH$
According to the balanced reaction, $2$ moles of $NaOH$ requires $2$ moles of $Na$.

So, $4$ g ($0.1$ mol) requires $0.1$ mol $=23\times 0.1=2.3$ g $Na$