Assertion (A): K, Rb and Cs form superoxides. | vedclass

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(C) Superoxides are species containing the $O_2^-$ ion,where oxygen has an oxidation state of $-\frac{1}{2}$.These are typically formed by larger alka

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$(A)$ is true but $(R)$ is not true

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(C) Superoxides are species containing the $O_2^-$ ion,where oxygen has an oxidation state of $-\frac{1}{2}$.These are typically formed by larger alkali metals such as $K, Rb$ and $Cs$,resulting in $KO_2, RbO_2$ and $CsO_2$.For salts containing large anions like $O_2^-$,the lattice energy increases as the size of the cation increases down the group.Since higher lattice energy contributes to greater thermodynamic stability of the ionic crystal,the stability of superoxides increases from $K$ to $Cs$.Therefore,the assertion $(A)$ is true,but the reason $(R)$ is false because stability increases due to an increase in lattice energy,not a decrease.

Assertion $(A)$: $K, Rb$ and $Cs$ form superoxides.
Reason $(R)$: The stability of the superoxides increases from $K$ to $Cs$ due to decrease in lattice energy.
The correct answer is

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Assertion $(A)$: $K, Rb$ and $Cs$ form superoxides.Reason $(R)$: The stability of the superoxides increases from $K$ to $Cs$ due to decrease in lattice energy.The correct answer is