Question

Assertion . Among the alkali metals , lithium salts exhibit the least electrical conductance in aqueous solutions .
Reason . Smaller the radius of the hydrated cation , lower is the electrical conductance in aqueous solutions .
A. If both assertion and reason are true, and reason is the true explanation of the assertion.
B. If both assertion and reason are true, but reason is not the true explanation of the assertion.
C. If assertion is true, but reason is false
D. If both assertion and reason are false.

Answer 1

Correct Answer - c
Correct reason . Among alkali metals , the extent of hydration decreases as the size of the cation increases from `Li^(+)` to `Cs^(+)` . In other words , `Li^(+)` ions are most highly hydrated (i.e., have the largest size) and hence their ionic mobility , i.e., conductance is the least among alkali metals .