What is the $\mathrm{pH}$ of a $2.6 \times 10^{-8} \mathrm{M~} \mathrm{H}^{+}$ion solution? $(\log 2.6=0…
What is the $\mathrm{pH}$ of a $2.6 \times 10^{-8} \mathrm{M~} \mathrm{H}^{+}$ion solution?
$(\log 2.6=0.4150)$
- $7.6$
- $6.9$
- $10.6$
- $8.4$
Solution
$\mathrm{pH}=-\log \left[\mathrm{H}^{+}\right]$
As $\left(\mathrm{H}^{+}\right)$ion conc. Is less, [ $\left.\mathrm{H}^{+}\right]$obtained from $\mathrm{H}_2 \mathrm{O}$ will be considered $\left[\mathrm{H}^{+}\right]$be considered
$\left[\mathrm{H}^{+}\right]$be considered
$\left[\mathrm{H}^{+}\right]$be considered
$\begin{aligned} & {\left[\mathrm{H}^{+}\right]=2.6 \times 10^{-8}+1 \times 10^{-7}} \\ & =1.26 \times 10^{-7}\end{aligned}$
$=1.26 \times 10^{-7}$
$\begin{aligned} & \therefore \mathrm{pH}=-\log \left[\mathrm{H}^{+}\right] \\ & =\log \left(1.26 \times 10^{-7}\right) \\ & =7-\log 1.26 \\ & =7-0.1 \\ & \mathrm{pH}=6.9\end{aligned}$
Asked in: MHT CET 2022 (05 Aug Shift 2)
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