Question

$0.1\, (M)\, HCl$ and $0.1\, (M)\, H_2SO_4$ each of volume $2ml$ are mixed and the volume is made up to $6\, ml$ by adding $2\,ml$ of $0.01\, (N)\, NaCl$ solution. The $pH$ of the resulting mixture is

• A. 1.17
• B. 10
• C. 0.3
• D. $\log\, 2 - \log\, 3$

Answer 1

Answer: (B)

10

Answer 2

Mili moles of $H^{+}=0.1 \times 2+0.1 \times 2 \times 2=0.6$
Total volume in $m l=6$
$p H=-\log _{10}\left[H^{+}\right]$
$=-\log \left(\frac{0.6}{6}\right)=-\log 0.1=1$