Questions 42-43 refer to the following. H2(g) + Cl2(g) <=> 2 HCl(g) K_p = 2 x 10^30 at 298 K HCl(g) — Equilibrium Chemistry Question
Question
Questions 42-43 refer to the following.
H2(g) + Cl2(g) <=> 2 HCl(g) K_p = 2 x 10^30 at 298 K
HCl(g) can be synthesized from H2(g) and Cl2(g) as represented above. A student studying the kinetics of the reaction proposes the following mechanism.
Step 1: Cl2(g) → 2 Cl(g) (slow) ΔH° = 242 kJ/mol_rxn
Step 2: H2(g) + Cl(g) → HCl(g) + H(g) (fast) ΔH° = 4 kJ/mol_rxn
Step 3: H(g) + Cl(g) → HCl(g) (fast) ΔH° = -432 kJ/mol_rxn
Which of the following statements identifies the greatest single reason that the value of K_p for the overall reaction at 298 K has such a large magnitude?
The activation energy for step 1 of the mechanism is large and positive.
The activation energy for step 2 of the mechanism is small and positive.
The value of ΔS° for the overall reaction is small and positive.
The value of ΔH° for the overall reaction is large and negative.