Question

A reaction profile (not to scale!) for the reaction C2H4 + HClC2H5Cl is shown below:

E (kJ) 205 C2H4 + HCI C2H5CI Reaction Coordinate

Which of the following are true? Choose all that apply.

1. The value of Ea in the presence of a catalyst would be larger than 205 kJ. E is positive.

2. The energy of the products is lower than the energy of the reactants.

3. The value of E in the presence of a catalyst would be smaller than -70.0kJ

4. The magnitude of Ea for the reverse reaction is larger than 205 kJ.

Answer 1

E (KJ) C2H₂ + Ha 70 205+70 = 275 (energy Ea for the reverse ran C2 Hg a Reaction coordinate → From the reaction profila diagram. we can say that - The energy of the product is lower than the energy of the reactants and magnitude of Ea for the reverse reaction is larger than 205 kJ as indicated above. The activation energy for the reverse reaction is 275 kJ. Hence, option- & option-4 and true statement Note: In presence of catalyst activation energy lowers not increases. so in presence of catalyst Ea will be lower than 205 kJ. so, 1st statement is false. catalyst doesn't change the energy level of reactant or product & it changes only the energy of the transition state or activated species. So, The value of doesn't changes in presence of catalyst. So option - 3 is also a false statement.