A compound MX2 has observed and normal molar masses 65.6 and 164 respectively. Calculate the apparent degree of ionization of MX2:

i=Normal molar massObserved molar mass=16465.6=2.5α=i−1n−1,n=3(number of ions)=2.5−13−1=1.52=0.75∴ Percentage ionization of MX2 will be 75%.