Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R. Assertion A : LiF is sparingly soluble in water. Reason R : The ionic radius of $\mathrm{Li}^{+}$ ion is smallest among its group members, hence has least hydration enthalpy. In the light of the above statements, choose the most appropriate answer from the options given below .

(A) Both A and R are true and R is the correct explanation of A

(B) Both A and R are true but R is NOT the correct explanation of A

JEE Main · 2022 · 26 Jul 2022 · Shift 2 · s-Block Elements

Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A : LiF is sparingly soluble in water.
Reason R : The ionic radius of

Li^{+}

ion is smallest among its group members, hence has least hydration enthalpy.
In the light of the above statements, choose the most appropriate answer from the options given below .

(A)Both A and R are true and R is the correct explanation of A
(B)Both A and R are true but R is NOT the correct explanation of A
(C)A is true but R is false✓ Correct
(D)A is false but R is true

Answer: (C)

Solution

Assertion A is true: LiF is sparingly soluble in water due to its very high lattice energy, which exceeds the hydration energy. Reason R is false:

Li^{+}

has the smallest ionic radius among group 1 elements, which gives it the HIGHEST (not least) hydration enthalpy. Answer: (C).

JEE Main · 2022 · 26 Jul 2022 · Shift 2 · Single correct option

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JEE Main · 2022 · 26 Jul 2022 · Shift 2 · s-Block Elements

Solution

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