Question

When $100$ of 1 M $NaOH$ solution and $10$ of 10 N $H_2{SO}_4$ solution are mixed together, the resulting solution will be:

• A. alkaline
• B. acidic
• C. strongly acidic
• D. neutral

Answer 1

The correct option is D neutral

Solution: $\left(D\right)$ neutral

As we know that,

Normality $=$ Molarity $\times$ valence factor

Therefore,

Molarity of $NaOH=1M\left(\text{Given}\right)$

Volume of $NaOH=100mL=0.1L$

$\therefore$ No. of moles of $NaOH=M\times V=1\times 0.1=0.1$

Molarity of $H_{2}S{O}_4=\frac{10}{2}=5M$

Volume of $H_{2}S{O}_4=10mL=0.01L$

$\therefore$ No. of moles of $H_{2}S{O}_4=M\times V=5\times 0.01=0.05$

$2NaOH+H_{2}S{O}_4⟶{Na}_{2}S{O}_4+2H_{2}O$

Since $0.1$ mole of $NaOH$ exactly neutralises $0.05$ mole of $H_{2}S{O}_4$( 0.1 Mole of H+), i.e., neither $NaOH$ nor $H_{2}S{O}_4$ is in excess and hence the solution will be neutral.