JEE MAIN - Chemistry (2013 (Offline) - No. 21)

The first ionization potential of Na is 5.1 eV. The value of electron gain enthalpy of Na+ will be:
– 5.1 eV
–10.2 eV
+ 2.55 eV
– 2.55 eV

Explanation

Ionization potential of Na means energy required to convert of Na to Na+ ion.

Na $$ \to $$ Na+ + e-          IE = 5.1 ev

Electron gain enthalpy of Na+ means energy required to convert Na+ ion to Na.

Na $$ \to $$ Na+ + e-          $$\Delta {H_{eq}}$$ = - 5.1 ev

According to Lavoisier and Laplace law of thermochemistry, when we change the direction of reaction then the sign of energy also changes.

Comments (0)

Advertisement