The correct relationship between the `pH` of isomolar solutions of sodium oxide `(pH_(1))`, sodium sulphide `(pH_(2))`, sodium selenide `(pH_(3))` and sodium telluride `(pH_(4))` is

Options

A. `pH_(1) gt pH_(2)~~pH_(3) gtPH_(4)`
B. `pH_(1) lt pH_(2) lt pH_(3) lt PH_(4)`
C. `pH_(1) lt pH_(2) lt pH_(3) ~~PH_(4)`
D. `pH_(1) gtpH_(2) gt pH_(3) gt PH_(3)`

Answer

D

Explanation

Acidic character increases in the order
`H_(2)O lt H_(2)S lt H_(2)Se lt H_(2)Te`
Basic character of conjugate bases will be in the order
`O^(2-)gt S^(2-) gt Se^(2-) gt Te^(2-)`
More the basic character, more the pH
`:.` pHs are in the order
`pH_(1)gt pH_(2)gt pH _(3) gt pH _(4)`