Answer:
Explanation:
Consider the reaction.A(g)↽−−⇀Z(g)A
A
(
g
)
↽
−
−
⇀
Z
(
g
)
The equilibrium constant,
K
, expresses the relationship between the concentrations of the species at equilibrium.
(g)
The energy of A-A bond in A is 98 kJ/mol. The energy of Z-Z bond in Z is 165 kJ/mol. Which statement about the reaction is correct?
1) The activation energy for the forward reaction, Reaction ↽−+X(g)AX(g), is smaller than the activation energy for the reverse reaction, Reaction ⇀+AX(g)↽−.
2) The amount of energy released when A and Z combine to form AX will be greater than the total energy needed to break both A-A and Z-Z bonds (above).
3) The amount of energy released when A and Z combine to form AX will be less than the total energy needed to break both A-A and Z-Z bonds.
4) The activation energy for the forward reaction, Reaction ↽−+X(g)AX(g), is greater than the activation energy for the reverse reaction, Reaction ⇀+AX(g)↽−.
5) The energy of A-A bond in A is greater than the energy of Z-Z bond in Z.
1) The activation energy for the forward reaction, Reaction ↽−+X(g)AX(g), is smaller than the activation energy for the reverse reaction, Reaction ⇀+AX(g)↽−.
It is correct that the activation energy for Reaction ↽−+X(g)AX(g) is smaller than that for Reaction ⇀+AX(g)↽−, because AX is less stable than A or Z, so it takes less energy to break the weaker bond in AX.
2) The amount of energy released when A and Z combine to form AX will be greater than the total energy needed to break both A-A and Z-Z bonds (above).
3) The amount of energy released when A and Z combine to form AX will be less than the total energy needed to break both A-A and Z-Z bonds.
Option (2) is incorrect because, though the formation of AX requires energy, which is not needed for the formation of A or Z; however, the total energy required to break both A-A and Z-Z bonds (above) is more than the amount released when A and Z combine to form AX.
Option (3) is incorrect because the amount of energy released when A and Z combine to form AX will be greater than the total energy needed to break both A-A and Z-Z bonds (above).
4) The activation energy for the forward reaction, Reaction ↽−+X(g)AX(g), is greater than the activation energy for the reverse reaction, Reaction ⇀+AX(g)↽−.
