Home / Assignment Help / If the rate-determining step limits the speed of a reaction, which statement is correct? Even if one or more fast steps occur in a reaction, the overall reaction cannot proceed any faster than the slowest step. If the first step is slow and the second step is fast, then the second step should determine the rate of the overall reaction. Increasing the concentration of a molecule that occurs in a fast step after a slow step will increase the overall rate of the reaction. In a unimolecular reaction where A decomposes to B and C, the rate of the reaction will decrease if the concentration of A is increased.

If the rate-determining step limits the speed of a reaction, which statement is correct? Even if one or more fast steps occur in a reaction, the overall reaction cannot proceed any faster than the slowest step. If the first step is slow and the second step is fast, then the second step should determine the rate of the overall reaction. Increasing the concentration of a molecule that occurs in a fast step after a slow step will increase the overall rate of the reaction. In a unimolecular reaction where A decomposes to B and C, the rate of the reaction will decrease if the concentration of A is increased.

A positive cahnge of enthalpy, ΔH rxn = + 55 kJ/mol, for the forward reaction means that the reaction is endothermic, i.e. the reactants absorb energy and the products are higher in energy.

Activation energy is the difference in the energy level of the reactants and the peak in the potential energy diagram (the energy of the transition state).

For an endothermic reaction, the products will be closer in energy to the transition state than what the reactans will be; so, the activation energy of the reversed reaction is lower than the activation energy of the forward reaction.

Activation energy of reverse and forward reactions is related by:

Activation energy of reverse rxn = Activation energy of forward rxn – ΔH rxn

=> Activiation energy of reverse rxn = 102 kJ/mol – 55 kJ/mol = 47 kJ/mol

Answer: 47 kJ/mol

About eduhawks

Check Also

Are the phases of the moon the same everywhere on earth

Are the phases of the moon the same everywhere on earth