The chlorine-atom-catalyzed chlorination of methane is thought to proceed by a t

Question

The chlorine-atom-catalyzed chlorination of methane is thought to proceed by a two-step mechanism:

CH4(g) + Cl(g) --> CH3(g) + HCl(g) (slow)
CH3(g) + Cl2(g) --> CH3Cl(g) + Cl(g)




(a) If the first step of this mechanism is rate-determining (slow), choose the correct rate law for the overall process.


Rate = k [CH4]2
Rate = k [Cl] [CH4]
Rate = k [CH4]2 [Cl2]
Rate = k [CH4] [Cl2]
Rate = k [Cl] [CH3]
Rate = k [CH3] [Cl2]




(b) Choose the correct chemical equation for the overall process.


CH4(g) + Cl2(g) --> CH3Cl(g) + HCl(g)
CH4(g) + Cl(g) --> CH3(g) + HCl(g)
CH3(g) + Cl2(g) --> CH3Cl(g) + Cl(g)




(c) Identify an intermediate in the reaction.


CH3
CH3Cl
CH4
Cl




(d) Identify the catalyst in the reaction.


CH4
Cl
CH3Cl
CH3




(e) Identify a reactant in the reaction.


Cl
CH3
CH4
CH3Cl




(f) Identify a product in the reaction.


CH4
CH3Cl
Cl
CH3

Explanation / Answer

(a) Rate = rate of slow step 1 = k[Cl][CH4]

Rate law: Rate = k[Cl][CH4]

(b) Add step 1 + step 2:

CH4(g) + Cl(g) + CH3(g) + Cl2(g) --> CH3(g) + HCl(g) + CH3Cl(g) + Cl(g)

Cancel common terms to get overall reaction:

CH4(g) + Cl2(g) --> HCl(g) + CH3Cl(g)

(c) Intermediate is species created and consumed in mechanism but does not appear in overall reaction:
CH3

(d) Catalyst is species that remains unchanged at end of the reaction: Cl

(e) Reactant is species that is consumed in the reaction and appears in overall reaction: CH4

(f) Product is species that is produced in the reaction and appears in overall reaction: CH3Cl

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.