Ea and H values of reactions R1, R2, R3 and R4 carried out at the same temperature are as given below: R1 Ea = 40 kJ mol–1, H = – 80 kJ mol–1 R2 Ea = 20 kJ mol–1, H = – 30 kJ mol–1 R3 Ea = 60 kJ mol–1, H = + 40 kJ mol–1 R4 Ea = 30 kJ mol–1, H = + 20 kJ mol–1 At a given temperature and assuming that the backward reactions of all these reactions have the same frequency factor, the rates of R1, R2, R3 and R4 in their respective backward reactions are in the increasing order of
A.R2 < R3 < R4 < R1
B.R4 < R3 < R2 <
C.R1 < R4 < R3 < R2
D.R1 < R2 < R3 < R4✓ Correct
Explanation
In 1 R Thus a E of Backward reaction 120 kJ/mole CHEMICAL KINETICS 41 In 2 R Thus a E of Backward reaction 50 kJ/mole In 3 R , Thus a E of backward Reaction 60 40 20 kJ/mole In 4 R Thus a E of backward reaction 30 20 10 kJ/mole As, Rate a 1 E Order of a E backward reaction 4 3 2 1 R R R R Thus, rate follows the order 1 2 3 4 R R R R