Question

In which one of the following arrangements the given sequence is not strictly according to the properties indicated against it?

Options

• CO₂ < SiO₂ < SnO₂ < PbO₂ : Increasing oxidizing power

• HF < HCl < HBr < HI : Increasing acidic strength

• H₂O < H₂S < H₂Se < H₂Te : Increasing pK_a values

• NH₃ < PH₃ < AsH₃ < SbH₃ : Increasing acidic character

Answer 1

H₂O < H₂S < H₂Se < H₂Te : Increasing pK_a values

Explanation:

As we go down Group 16, the acidity of hydrides increases, so pK_a values should decrease. The given sequence shows increasing pK_a values, which is incorrect. Hence, option H₂O < H₂S < H₂Se < H₂Te : Increasing pK_a values is not in the correct order.