Question

The number of hydroxide ions in 10 ml of an aqueous solution with $pOH$ $=$ ${10}^{-13}$ is:

• A. ${10}^{13}$
• B. $6.023\times {10}^8$
• C. $6.023\times {10}^{13}$
• D. $6.023\times {10}^{10}$

Answer 1

The correct option is B $6.023\times {10}^8$

Given that,

pOH $={10}^{-13}$

$\Rightarrow \left[O{H}^{-}\right]={10}^{-13},V=10ml=0.01L$.

$\therefore$ Moles of $O{H}^{-}ion={10}^{-15}$.

$\therefore$ No. of $O{H}^{-}ions={10}^{-15}\times N_A=6.023\times {10}^8$.