Question

The self ionization constant for pure formic acid, K = [HCOO H^+2][HCOO^â ] has been estimated as 10^â6 at room

Answer 1

Answer:

Given, the density of the formic acid is 1.22 g/cm3. Hence, the weight of the formic acid in the 1 litre solution = 1.22 x 103 . Thus, [HCOOH] = (1.22 * 10^3 )/ 46 = 26.5 M. As in the case of auto ionisation, [HCOOH2+] [HCOO-] = 10^(-6). Hence, [HCOO-] = [HCOOH2+] = 10^(-3). Now, % of dissociation of HCOOH = [HCOO-] * 100 / [HCOOH] = (10^(-3) * 100) / 26.5 = 0.004%.