Question

A solution is prepared at that is initially in chlorous acid , a weak acid with , and in potassium chlorite . Calculate the pH of the solution. Round your answer to decimal places.

Answer 1

The question is incomplete, here is the complete question:

A solution is prepared at 25°C that is initially 0.075 M in chlorous acid
`(HClO_2)` , a weak acid with
`K_a=1.1* 10^(-2)`, and 0.34 M in potassium chloride
`(KClO_2)` . Calculate the pH of the solution. Round your answer to 2 decimal places.

Answer: The pH of the solution is 2.62

Step-by-step explanation:

The chemical equation for the reaction of chlorous acid and potassium hydroxide follows:

`HClO_2+KOH\rightarrow KClO_2+H_2O`

To calculate the pH of acidic buffer, we use the equation given by Henderson Hasselbalch:

`pH=pK_a+\log(([salt])/([acid]))`

`pH=pK_a+\log(([NaHCO_3])/([H_2CO_3]))`

We are given:

`pK_a` = negative logarithm of acid dissociation constant of chlorous acid = 1.96

`[KClO_2]=0.34M`

`[HClO_2]=0.075M`

pH = ?

Putting values in above equation, we get:

`pH=1.96+\log((0.34)/(0.075))\\\\pH=2.62`

Hence, the pH of the solution is 2.62