Which of the following statements is incorrect ?

Options

A. The superoxide ion `(i.e. O_(2)^(-))` is stable only in presence of larger cations such as `K^(+),Rb^(+),Cs^(+)`
B. Alkali metals are normally kept in kerosene oil.
C. All the alkali metal hydrides are ionic solids with high melting points.
D. The concentrated solution of alkali metals in liquid ammonia is paramagnetic in nature.

Answer

4

Explanation

`(1)` Bigger anion is stablised by bigger cation through lattice energy effect.
`(2)` Because of their high reactivity towards air and water.
`(3)` True statement.
`(4)` In concentrated solution, unpaired electrons with opposite spins paired up `-` forming the solution diamagnetic.