Question

The $pH$ of the solution formed by mixing $20\, m L$ of $0.05 \,M\,H _{2} SO _{4}$ with $5.0\, m L$ of $0.45\, M\, NaOH$ at $298\, K$ is

• A. 6
• B. 2
• C. 12
• D. 7

Answer 1

Answer: (C)

$0.05\, M\, H _{2} SO _{4}=0.05 \times 2=0.1\, N\, H _{2} SO _{4}$
$0.45 \,M \,NaOH =0.45 \times 1=0.45 \,N\, NaOH$
Meq. of $H _{2} SO _{4}=0.1 \times 20=2$
Meq. of $NaOH =0.45 \times 5=2.25$
Meq, of $NaOH$ left $=2.25-2=0.25$
Hence, resulting solution is alkaline in nature.