Question

Calculate ${\text{pH}}$ of ${\text{1}}{{\text{0}}^{{\text{ - 8}}}}$M ${\text{NaOH}}$ of the solution.

Answer 1

Hint: ${\text{pH}}$ means negative logarithm of the hydrogen ion concentration and it can be represented in the form of formula as follows.
${\text{pH}}$= ${\text{ - log[}}{{\text{H}}^{\text{ + }}}{\text{]}}$ and the relation between ${\text{pH}}$ and ${\text{pOH}}$ is as follows.
${\text{pH}}$+ ${\text{pOH}}$=$14$

Complete step by step answer:
We know that the hydroxyl ion concentration of neutral water = ${10^{ - 7}}$
Now we have to find ${\text{pH}}$ of the solution.
We can find the ${\text{pOH}}$ by using the concentration of the hydroxyl ion in the solution.
The ${\text{pOH}}$ of the given solution is
${\text{pOH}}$=$ - \log [{10^{ - 8}} + {10^{ - 7}}]$
= $ - \log {10^{ - 7}}(0.1 + 1)$
And hence on doing the simplification,w have
=${\text{7 - log(1}}{\text{.1)}}$
= ${\text{7 - 0}}{\text{.0953}}$=$6.9047$
$\therefore $${\text{pH}}$= \[14 - 6.9047 = 7.0953\]

Additional Information:
In the formula ${\text{pH}}$=${\text{ - log[}}{{\text{H}}^{\text{ + }}}{\text{]}}$, the concentration of Hydrogen ion is always expressed in Molarity. The concept and formula of ${\text{pH}}$ was given by Sorenson. We can find the ${\text{pH}}$ of any solution by the concentration of Hydrogen ions present in the solution and Concentration of Hydrogen ions can be found by ${\text{pH}}$ of the solution. We use indicators to measure ${\text{pH}}$. We use the fact that indicators of color changes with ${\text{pH}}$.We use a visual comparison of the color of a test solution with a standard color chart that provides a means to measure pH accurate to the nearest whole number. And that nearest whole number is our measured ${\text{pH}}$.

Note:
${\text{pH}}$ means power of hydrogen means the concentration of the hydrogen ion present in the given solution. By using pH value we can say whether the solution is acidic or basic. If ${\text{pH}}$ of the solution is less than $7$ then the solution is called acidic and if ${\text{pH}}$ of the solution is greater than $7$ then that solution is called basic solution.