CHM 123HW – Chapter 13-Chemical KineticsName

Due Tuesday 10/18/16

Don’t forget to show all your work

  1. The table presents data for the reaction: 2H2(g) + 2NO(g) 2H2O(g) + N2(g)

The temperature of the reaction is constant. Initial Concentration (M) / Initial Rate
Exp. / [NO] / [H2] / –Δ[NO]/Δt (M/s)
1 / 0.60 / 0.10 / 1.8×10-3
2 / 0.60 / 0.20 / 3.6×10-3
3 / 0.10 / 0.60 / 3.0×10-4
4 / 0.20 / 0.60 / 1.2×10-3
  1. Write a generic rate law for this reaction
  1. Calculate the order of H2 and NO
  1. What is the value of k for the above reaction system.
  1. Write a complete rate law for the reaction
  1. Calculate the necessary [NO] to achieve a rate of 8.0×10-4 M/s when [H2] = 0.35 M.
  1. What is the rate of production of N2(g) in trial #3?
  1. The first-order reaction, 2 N2O(g) → 2 N2(g) + O2(g), has a rate constant equal to 0.76 s-1 at 1000 K. How long will it take for the concentration of N2O to decrease to 42% of its initial concentration?
  1. Nitrosyl bromide decomposes at 10.0oC

2 NOBr(g)  2 NO(g) + Br2(g)

Use the following kinetic data to determine the order of the reaction and the value of the rate constant for the consumption of NOBr (hint: using graphical method and attach or draw it)

Time(s) / 0 / 10 / 20 / 30 / 40
[NOBr] / 0.0400 / 0.0303 / 0.0244 / 0.0204 / 0.0175
  1. In the presence of excess thiocyanate ion, SCN-, the following reaction is first order in chromium (III) ion, Cr3+; The half-life is 96.0 hours.

Cr3+(aq) + SCN-(aq)  Cr(SCN)2+(aq)

  1. What is the rate constant, k?
  1. How long (in hours) would be required for the initial concentration to decrease to 35.5%?
  1. What is the concentration of Cr3+ after 110.0 hours if the initial concentration was 2.60 x 10-4M

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