Question

The $pH$ of the solution obtained by mixing $10mL$ of ${10}^{-1}HCl$ and $10mL$ of ${10}^{-1}NNaOH$ is:

• A. $8$
• B. $2$
• C. $7$
• D. none of these

Answer 1

The correct option is C $7$

$NaOH+HCl⟶$$NaCl+H_{2}O$

1 mole of $NaOH$ reacts with 1 mole $HCl$

Mole of $HCl$ in 10 ml of $0.1$ M $HCl=$ $\frac{10}{1000}\times 0.1=0.001$

Mole of $NaOH$ in 10 ml of $0.1$ M $NaOH=$ $\frac{10}{1000}\times 0.1=0.001$

0.001 mole of $HCl$ is completely neutralised by 0.001 mole of $NaOH$

So the solution is neutral means $pH=7$