Question

The $pH$ of a solution is $3.7.$ The concentration of proton is in the order$?$

• A. ${10}^{-2}M$
• B. ${10}^{-4}M$
• C. ${10}^{-6}M$
• D. ${10}^{-8}M$

Answer 1

Answer: (B)

${10}^{-4}M$

Given,

$pH$ of solution $=3.7$

$⟹pH=-\log \left[H^{+}\right]$

$⟹3.7=-{\log }_{10}\left[H^{+}\right]$

$⟹\left[H^{+}\right]={10}^{-3.7}$

$⟹\left[H^{+}\right]=2\times {10}^{-4}$ $M$

The concentration of proton is of order ${10}^{-4}$ $M$