Question

Calculate the ph of a buffer that is 0.94 mhc2h3o2 and 0.059 mnac2h3o2. the ka for hc2h3o2 is 1.8×10−5. calculate the of a buffer that is 0.94 and 0.059 . the for is . 2.86 3.54 4.74 1.80 5.97

Answer 1

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:

$pH=pK_a+\log(\frac{[salt]}{[acid]})$

$pH=pK_a+\log(\frac{[NaHCO_3]}{[H_2CO_3]})$

We are given:

$pK_a$ = negative logarithm of acid dissociation constant of carbonic acid

$pK_a=-\log[K_a]=-\[1.8\times 10^{-5}]=4.74$

$[NaC_2H_3O_2]=0.059 M$

$[HC_2H_3O_2]=0.94 M$

pH = ?

Putting values in above equation, we get:

$pH=4.74+\log(\frac{0.059 M}{0.94})\\\\pH=3.537\approx 3.54$

The pH of the buffer is 3.54.