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
Uitleg
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.
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.