Answer:
The pH of the buffer is 3.54.
Explanation:
To calculate the pH of acidic buffer, we use the equation given by Henderson Hasselbalch:
[tex]pH=pK_a+\log(\frac{[salt]}{[acid]})[/tex]
[tex]pH=pK_a+\log(\frac{[NaHCO_3]}{[H_2CO_3]})[/tex]
We are given:
[tex]pK_a[/tex] = negative logarithm of acid dissociation constant of carbonic acid
[tex]pK_a=-\log[K_a]=-\[1.8\times 10^{-5}]=4.74[/tex]
[tex][NaC_2H_3O_2]=0.059 M[/tex]
[tex][HC_2H_3O_2]=0.94 M[/tex]
pH = ?
Putting values in above equation, we get:
[tex]pH=4.74+\log(\frac{0.059 M}{0.94})\\\\pH=3.537\approx 3.54[/tex]
The pH of the buffer is 3.54.
