Ascorbic acid (H2C6H6O6; H2Asc for this problem), known as vitamin C, is a diprotic acid (Ka1= 1.0x10–5 and Ka2= 5x10–12) found in citrus fruit. Calculate [HAsc–], [Asc2–], and the pH of 0.050 M H2Asc.

The concentrations are :

The pH of the solution is 3.15.

Explanation:

Initial

c                0              0

Equilibrium

c-x                x          x

Solving for x:

x = 0.000702 M

Initially

x                0          0

At equilibrium ;

(x - y)            y         y

Putting value of x = 0.000702 M

Total concentration of

The pH of the solution :