JEE Main20198 Apr 2019Morning ShiftChemistrys Block ElementsActual
The correct order of hydration enthalpies of alkali metal ions is:
Options
- AN a + > L i + > K + > R b + > C s +
- BN a + > L i + > K + > C s + > R b +
- CL i + > N a + > K + > R b + > C s +
- DL i + > N a + > K + > C s + > R b +
Correct answer
C. L i + > N a + > K + > R b + > C s +
Step-by-step solution
Hydration Enthalpy ∝ + q .   ( - q   )                                                                           ∝ 1 r + + 1 r - As radius increases enthalpy of hydration decreases so in a group on going from top to bottom hydration enthalpy decreases. L i + >   N a + >   K + >   R b +