Question

What is the pH of the 0.0605 M solution of sodium hydroxide, NaOH?

Answer 1

Before solving this question, we should first know about the formula to calculate pH. $pH=-\log \,({{H}^{+}})$ or $pOH=-\log ([O{{H}^{-}}])$. The calculation of the Acidity or alkalinity of a solution is known as pH. The relative quantity $({{H}^{+}})$ is stated by pH. Acidity depends on the concentration of the $({{H}^{+}})$ ions. If the concentration of$({{H}^{+}})$ ions is more, then more is the acidity of the solution. Now, we can apply this formula and solve the numerical easily.

Complete answer:
NaOH is a strong base in a solution, which means it will dissociate completely in the aqueous solutions to form sodium cations $N{{a}^{+}}$and hydroxide anions $O{{H}^{-}}$
This shows that every mole of NaOH that we mix in the water, we will get one mole of hydroxide ions.
Therefore, the concentration of hydroxide ions = Sodium hydroxide
First, we know the concentration of $O{{H}^{-}}$that is present in the water at a particular temperature.
$[O{{H}^{-}}]=NaOH=0.0605M$
As we know the concentration of hydroxide ions, we can easily calculate pOH with the help of the formula written below.
$pOH=-\log ([O{{H}^{-}}])$
Now, putting values in the formula gives
$pOH=-\log ([0.0605])$
$pOH=1.22$
As we know the aqueous solutions at room temperature-
$pH+pOH=14$
Putting the value of $pOH=1.22$ in the relation
$pH+1.22=14$
$pH=12.78$

Note:
pH has various uses like
Hydrochloric acid in our stomach helps to digest the food without damaging our stomach. But if the concentration of acid exceeds a certain limit, then we face problems like pain and indigestion. SO, to neutralize it Antacids are taken to balance the pH.
Soils need a certain amount of pH to be fertile. The soil should not be too acidic or too alkaline. It hampers the growth of the plant.