Question

$4 g$ equimolar mixture of $NaOH$ and $Na _{2} CO _{3}$ contains $x g$ of $NaOH$ and y $g$ of $Na _{2} CO _{3}$. The value of $x$ is _______ $g$.

Answer 1

Total mass $=4 g$
NOW
$NaOH : 'a'$ mol $W_{ NaOH }+W_{ Na _{2} CO _{3}}=4$
$Na _{2} CO _{3} :'a' $ mol $\Rightarrow 40 a+106 a=4$
$\Rightarrow a=\frac{4}{146} \text { mol }$
$\Rightarrow$ therefore mass of $N a O H$ is
$: \frac{4}{146} \times 40\, g$
$=1.095 \approx 1$