Answer :
Answer:
pH will be 4.86.
Explanation:
On mixing sodium acetate (a salt of acetic acid) with acetic acid we get buffer solution.
Let us calculate the moles of each species taken:
Moles of sodium acetate = molarity X volume(L)
= 0.4364 X 35.81 X 10⁻³= 0.0156 mol
the moles of acetic acid = molarity X volume(L)
= 0.3183 X 38.23 X 10⁻³= 0.0121 mol
The moles of NaOH added = molarity X volume(L)
= 0.0588 X 3.524 X 10⁻³= 0.000207 mol
The base added will react with the acetic acid producing equal moles of sodium acetate
[tex]CH_{3}COOH+NaOH-->CH_{3}COONa+H_{2}O[/tex]
The moles of acetic acid reacted = moles of base added = 0.000207 mol
The moles of acetic acid left = 0.0121-0.000207 = 0.0119 mol
The moles of sodium acetate formed = 0.000207 mol
The new moles of sodium acetate = 0.0156+0.000207=0.0158 mol
The pH of buffer is calculated using Henderson Hassalbalch's equation
pKa of acetic acid = 4.74
[tex]pH=pKa+log\frac{[salt]}{[acid]}=4.74+log\frac{0.0158}{0.0119}=4.86[/tex]