Question

The number of $H^{+}$ present in $1$ mL solution whose $pH=13$ is $X\times {10}^7$. The value of $X$ is

Answer 1

$pH=13$

Hence, $H^{+}={10}^{-13}M$

The number of moles of $H^{+}$ ions present in 1 ml are $\frac{1}{1000}L\times {10}^{-13}\frac{mol}{L}={10}^{-16}mol$

The number of $H^{+}$ ions present in 1 ml are ${10}^{-16}mol\times 6.023\times {10}^{23}\frac{ions}{mol}=6\times {10}^7=X\times {10}^7$

Hence, $X=6$