Question

The heat enegry required to ionise the following molecules is given as follows:
`N_(2)(g) overset(DeltaH_(1))rarr N_(2)^(o+(g),O_(2)(g) overset(DeltaH_(2))rarrO_(2)^(o+(g)`
`Li_(2)(g) overset(DeltaH_(3))rarrLi_(2)^(o+(g),C_(2)(g) overset(DeltaH_(4))rarrC_(2)^(o+(g)`
Arrange the heat terms in decreasing order of enegry:
A. `DeltaH_(1) gt DeltaH_(3) gt DeltaH_(2) gt DeltaH_(4)`
B. `DeltaH_(2) gt DeltaH_(3) gt DeltaH_(1) gt DeltaH_(4)`
C. `DeltaH_(3) gt DeltaH_(4) gt DeltaH_(1) gt DeltaH_(2)`
D. `DeltaH_(3) gt DeltaH_(1) gt DeltaH_(4) gt DeltaH_(2)`

Answer 1

Enthalpy of ionisation depends upon the size of molecules. Larger the size lesser will be ionisation energy.