Unformatted text preview: CHM 152, Group Work 1, Spring 2009, Burk, Names: ___________________________________ due 2‐3‐9 1. Write the rate equalities for this unbalanced reaction: CH4(g) + O2(g) CO2(g) + H2O(g) 2. Without any experimental data, write the rate law for the above reaction. ___________________________ 3. Calculate the average rate if initially the reactant concentration is 2.0M and after 10.0 seconds the reactant concentration is 0.50M. Show your work and circle your final answer. a. +0.15 M/s b. ‐0.15 M/s c. +6.7 M/s d. ‐6.7 M/s e. ‐15.0 M/s 4. To graphically find the rate constant for a first order reaction you should plot ___________ versus ______. 5. What percentage of a sample would remain after four half‐lives? _____________ 6. According to the following unbalanced reaction, if the rate of appearance of oxygen gas is 4.00 x 10‐2 M/s, what is the rate of disappearance of KClO3 (g)? KClO3(g) → KCl(g) + O2(g) (high Temp rxn) Show your work and circle your final answer. a. 2.67 x 10‐2 M/s b. 6.00 x 10‐2 M/s c. 2.00 x 10‐2 M/s d. 3.00 x 10‐2 M/s e. 5.33 x 10‐2 M/s 7. What is the half‐life for a first order reaction if the initial concentration of reactant is 1.25M and after 69.2 seconds the concentration has dropped to 0.955M? Show your work and circle your final answer. a. 178 s b. 232 s c. 0.00389 s d. 39.3 s e. 389 s 8. What is the reactant concentration after 78.9 seconds for a second order reaction with a half‐life of 3.l0 minutes if the initial concentration was 0.555M? Show your work and circle your final answer. a. 0.0392M b. 0.390M c. 0.477M d. 0.0514M e. 0.0210M 9. The rate law for a reaction is rate = k[H2][F2]. If the rate is 3.15 x 10‐4 M/s when [H2] = 0.084 M and [F2] = 0.25 M, calculate the rate when [H2] = 0.039 M and [F2] = 0.099 M. Show your work and circle your final answer. a. 0.015 M/s b. 2.6 x 10‐8 M/s c. 5.8 x 10‐5 M/s d. 6.3 x 10‐6 M/s e. 1.6 x 10‐3 M/s 10. The following experimental data was collected for this reaction. 2 NO(g) + 2 H2(g) N2(g) + 2 H2O(g). What is the rate law? Show your work and circle your final answer. Trial [NO] (M) [H2] (M) Rate (M/s) 1 0.60 0.15 0.076 2 0.60 0.30 0.15 3 0.60 0.60 0.30 4 1.20 0.60 1.21 ...
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