Question

What will be $pH$ of $5.0\times 10^{-2}MNaOH$ solution?
$(\log 2=0.3)$

• A. 14.00
• B. 13.70
• C. 13.00
• D. 12.70

Answer 1

Answer: (D)

Given $\left[O{H}^{-}\right]=5\times 10^{-2}$
$\therefore pOH=-\log 5\times 10^{-2}$
$=-\log 5+2\log 10=1.30$
$\because pH+pOH=14$
$\because pH=14-pOH$
$=14-1.30=12.70$