The first $$\left( {{\Delta _i}{H_1}} \right)$$ and second $$\left( {{\Delta _i}{H_2}} \right)$$ ionisation enthalpies $$\left( {{\text{in}}\,\,kJ\,\,mo{l^{ - 1}}} \right)$$ and the electron gain enthalpy $$\left( {{\Delta _{eg}}H} \right)\left( {{\text{in}}\,\,kJ\,\,mo{l^{ - 1}}} \right)$$ of the elements I, II, III, IV and V are given below :
Element
$${\Delta _l}{H_1}$$
$${\Delta _l}{H_2}$$
$${\Delta _{eg}}H$$
I
520
7300
− 60
II
419
3051
− 48
III
1681
3374
− 328
IV
1008
1846
− 295
V
2372
5251
+ 48
The most reactive metal and the least reactive non-metal of these are respectively
A.
I and V
B.
V and II
C.
II and V
D.
IV and V
Answer :
II and V
Solution :
I represents $$Li$$ , II represents $$K$$, III represents $$F$$, IV represents $$I$$, V represents $$He.$$
So, amongst these, II represents most reactive metal and V represents least reactive non-metal.
Releted MCQ Question on Inorganic Chemistry >> Classification of Elements and Periodicity in Properties
Releted Question 1
The correct order of second ionisation potential of carbon, nitrogen, oxygen and fluorine is