Question

$100{\text{cm}}^3$ of a $0.1\text{N}HCl$ solution is mixed with $100{\text{cm}}^3$ of a $0.2\text{N}NaOH$ solution. The resulting solution has:

• A. Normality of $O{H}^{-}=0.1\text{N}$ and the solution is basic
• B. Normality of $H^{+}=0.1\text{N}$ and the solution is acidic
• C. Normality of $O{H}^{-}=0.05\text{N}$ and the solution is basic
• D. Normality of $H^{+}=0.05\text{N}$ and the solution is acidic

Answer 1

The correct option is C Normality of $O{H}^{-}=0.05\text{N}$ and the solution is basic

Milliequivalents of $HCl$ $=0.1\times 100=10$
Milliequivalents of $NaOH$ $=0.2\times 100=20$
Since the number of equivalents of the base is greater, the solution will be basic.
Number of milliequivalents of $O{H}^{-}$ left after neutralization = 10
Normality of $O{H}^{-}$ ions in solution $=\frac{\text{number of milli-equivalents left}}{\text{total volume of the solution in mL}}$
$=\frac{10}{100+100}=0.05\text{N}$