Answer to Question #56552 in Inorganic Chemistry for amna iqbal

Question

a one molar solution of HCl is about 92 percent ionized at room temperature .Calculate Ka for HCl.

Answer 1

The Ka value for the reaction
HCl → H+ + Cl-
is defined:
Ka = ([H+][Cl-])/[HCl], where [H+] – the concentration of protons, [Cl-] – the concentration of chloride anions, [HCl] – the concentration of non-ionized HCl.
If the degree of ionization is 92%, the concentration of protons and chloride anions equal:
[H+] = [Cl-] = 0.92 mol
The remaining amount of non-ionized HCl is:
[HCl] = 1 mole – 0.92 mol = 0.08 mol.
Thus, Ka for HCl is:
Ka = (0.92)2/0.08 = 10.58