Question

White vinegar is a 5.0% by mass solution of acetic acid in water. If the density of white

vinegar is 1.007 g/cm3

, what is the pH?​

Answer 1

The pH = 2.41

Further explanation

Given

5.0% by mass solution of acetic acid

the density of white vinegar is 1.007 g/cm3

Required

pH

Solution

Molarity of solution :

`\tt M=(\%mass* \rho* 10)/(MW~acetic~acid)\\\\M=(5* 1.007* 10)/(60)\\\\M=0.839`

Ka for acetic acid = 1.8 x 10⁻⁵

[H⁺] for weak acid :

`\tt [H^+]=√(Ka.M)`

Input the value :

`\tt [H^+]=\sqrt{1.8* 10^(-5)* 0.839}\\\\(H^+]=0.00388=3.88* 10^(-3)\\\\pH=3-log~3.88=2.41`