In which of the following arrangements the given sequence is not strict according to the property indicated against it?

Options

A. `HF lt HCI lt HBr lt HI` : increasing acidic strength
B. `H_(2)O lt H_(2)S lt H_(2)Se lt H_(2)Te` : increasing `pK_(a)` values
C. `NH_(3) lt PH_(3) lt AsH_(3) lt SbH_(3)` : increasing acidic character
D. `CO_(2) lt SiO_(2) lt SnO_(2) lt PbO_(2)` : increasing oxidising power.

Answer

B

Explanation

The acidic strength of hydrides in group 16 elements increases with the increase the size of the element. This means that `pK_(a)` is to be in decreasing order. The increasing `pK_(a)` order is the reverse
`H_(2)Te lt H_(2)Se lt H_(2)S lt H_(2)O`.