Question

Which has the highest $pH$?
A.$C{H_3}COOK$
B.$N{a_2}C{O_3}$
C.$N{H_4}Cl$
D.$NaN{O_3}$

Answer 1

$pH$ can be defined as a scale, which is used to measure how acidic or basic an aqueous solution is.

Complete step by step answer:
The expanded form of $pH$ is the potential of hydrogen or power of hydrogen. In chemistry, $pH$ is a scale that is used to measure the acidity or basicity of an aqueous solution. Acidic solutions are tending to have lower values of $pH$ and basic or alkaline solutions have higher values.
The value of $pH$ ranges from 0-14. For acids, $pH < 7$ ; for bases $pH > 7$; for neutral solutions $pH = 7$
In the above asked question, $C{H_3}COOK$ is a salt formed by the reaction between an acid $C{H_3}COOH$ (weak acid) and a base $KOH$ (strong base). The salt formed when it undergoes hydrolysis, its $pH$ value increases above 7 and thus the salt will be slightly basic in nature.
Sodium carbonate $N{a_2}C{O_3}$ is a base and ultimately its $pH$ value will be much greater than 7.
When a weak base ammonium hydroxide $N{H_4}OH$ reacts with a strong acid hydrochloric acid $HCl$, it gives ammonium chloride $N{H_4}Cl$ salt as the product. Its $pH$ value will be slightly lesser than 7.
When a strong acid like nitric acid $HN{O_3}$ reacts with a strong base such as sodium hydroxide $NaOH$, $NaN{O_3}$ salt is formed. Since, it is a combination of a strong acid and a strong base, so the $pH$ of the salt solution produced will be neutral, i.e., 7.

So, the correct option is B.

Note:
Note: Measurement of $pH$plays an important role in analyzing the chemical condition of a solution. It has got a wide range of applications in fields of agriculture, environment monitoring, treatment of wastewater, in research and development.