Elementary Reactions and Intermediates

 1) Which of the following reactions could be elementary and unimolecular reactions?

     (a) O₃(g) O₂(g) + O(g)

     (b) Br₂(g) 2Br(g)

     (c) O₃(g) + O(g) 2O₂(g)

     (d) 2NO(g) + 2H₂(g) N₂(g) + 2H₂O(g)

 2) Suppose that for the reaction of nitrogen dioxide and carbon monoxide

NO₂(g) + CO(g) NO(g) + CO₂(g)

the following mechanism has been proposed at high temperatures

NO₂ + CO O-N-O-C-O (slow)

O-N-O-C-O NO + CO₂ (fast)

Which of the following is an intermediate in this mechanism?

     (a) NO₂

     (b) O-N-O-C-O

     (c) NO

     (d) CO

 3) Which of the following reactions could be elementary and unimolecular reactions?

     (a) H(g) + Br₂(g) HBr(g) + Br(g)

     (b) (CH₃)₃CBr(g) (CH₃)₃C⁺(g) + Br^-(g)

     (c) 2H₂(g) + O₂(g) 2H₂O(g)

     (d) I₂(g) 2I(g)

  4) Suppose that for the reaction of nitrogen dioxide and carbon monoxide

NO₂(g) + CO(g) NO(g) + CO₂(g)

the following mechanism has been proposed at high temperatures

NO₂ + NO₂ NO₃ + NO (slow)

NO₃ + CO NO₂ + CO₂ (fast)

Which of the following is an intermediate in this mechanism?

     (a) NO₂

     (b) NO

     (c) NO₃

     (d) CO₂

 5) Which of the following reactions could be elementary and bimolecular reactions?

     (a) 2O₃(g) 3O₂(g)

     (b) N₂O₄(g) 2NO₂(g)

     (c) NO(g) + O₃(g) NO₂(g) + O₂(g)

     (d) 2NO(g) + O₂(g) 2NO₂(g)

 6) Which of the following reactions could not be elementary reactions?

     (a) 2SO₂(g) + O₂(g) 2SO₃(g)

     (b) FClO₂(g) FClO(g) + O(g)

     (c) 2NO₂(g) NO(g) + NO₃(g)

     (d) 2ICl(g) + H₂(g) I₂(g) + 2HCl(g)