Question

The pKa values of HCl is -7.0 and that of HI is -10.0. Which is the stronger acid?

Answer 1

For HCl, pK_a = -7.0, hence its dissoClation constant is, K_a = 1 x 10^-7. 

For HI pK_a = – 10.0, hence its dissoClation constant is K_a = 1 x 10^-7. 

Hence HCl dissoClates more than HI. 

Therefore HCl is a stronger acid than HI.