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Student Copy HW 13B
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CHE 134 smr ’11 – HW 13B Name:____________________________________________________________ ________ 1.What changes would alter the rate constant (k) for the reaction 2A + B products? 2.If E a for a certain biological reaction is 50. kJ/mol, by what factor (how many times) will the rate of this reaction increase when body temperature increases from 37°C (normal) to 40°C (fever)? 3.At 30°C, by how much is a reaction's activation energy decreased by the addition of a catalyst if the catalyst triples the reaction rate? 4.The activation energy for the following reaction is 60. kJ/mol. Sn 2+ + 2Co 3+ Sn 4+ + 2Co 2+ By what factor (how many times) will the rate constant increase when the temperature is raised from 10°C to 28°C?
Transcript of Student Copy HW 13B
CHE 134 smr ’11 – HW 13B
Name:____________________________________________________________________
1.What changes would alter the rate constant (k) for the reaction 2A + B products?
2.If Ea for a certain biological reaction is 50. kJ/mol, by what factor (how many times) will the rate of this reaction increase when body temperature increases from 37°C (normal) to 40°C (fever)?
3.At 30°C, by how much is a reaction's activation energy decreased by the addition of a catalyst if the catalyst triples the reaction rate?
4.The activation energy for the following reaction is 60. kJ/mol.Sn2+ + 2Co3+ Sn4+ + 2Co2+
By what factor (how many times) will the rate constant increase when the temperature is raised from 10°C to 28°C?
5.Calculate the activation energy, in kJ/mol, for the redox reactionSn2+ + 2Co3+ Sn4+ + 2Co2+.
Temp (°C) k (1/M·s) 2 3.12 103
27 27.0 103
6.According to the collision theory, all collisions do not lead to reaction. Name 2 reasons why not all collisions between reactant molecules lead to reaction?
CHE 134 smr ’11 – HW 13B
7. A reaction mechanism usually isA) the same as the balanced chemical equation.B) restricted to only one possible explanation.C) obvious if the reaction order is known.D) difficult, if not impossible, to prove.E) obvious if the activation energy is known.
8.The rate law for the reaction H2O2 + 2H+ + 2I – I2 + 2H2O is rate = k[H2O2][I –]. The following mechanism has been suggested.H2O2 + I – HOI + OH – slowOH – + H+ H2O fastHOI + H+ + I – I2 + H2O fast
Identify all intermediates included in this mechanism.
9.For the reaction X2 + Y + Z XY + XZ, it is found that the rate equation is rate = k [X2][Y]. Why does the concentration of Z have no effect on the rate?
10. The gas phase reaction of nitrogen dioxide and carbon monoxide was found by experiment to be second-order with respect to NO2, and zeroth-order with respect to CO below 25°C.NO2 + CO NO + CO2
Which one of the following mechanisms is consistent with the observed reaction order?A) NO2 + 2CO N + 2CO2 fast
N + NO2 2NO slowB) NO2 + 2CO N + 2CO2 slow
N + NO2 2NO fastC) NO2 + NO2 NO3 + NO fast
NO3 + CO NO2 + CO2 slowD) NO2 + NO2 NO3 + NO slow
NO3 + CO NO2 + CO2 fast
