Exploring Creation Chemistry Module #14 Test
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01. A chemist makes a solution of NaI (aq) to use as a reactant in an experiment. She makes 500 mL of the solution and only uses 100 mL in the experiment. When she does the experiment, she measures the rate of the reaction that involves NaI. She then takes the 400 mL of left over NaI (aq) and boils it down to only 100 mL. She then allows the NaI solution to cool back down to its original temperature and runs the same experiment again, with this new sample of NaI (aq). Will the rate she measures be larger, smaller, or the same as the rate she measured originally?
02. Explain in your own words why increasing the temperature of a reaction will increase its rate.
03. If the order of a chemical reaction with respect to one of its reactants is zero, how does that reactant's concentration affect the rate of the chemical reaction?
04. What part of the rate equation depends on the temperature of the reaction?
05. Two different reactions have exactly the same activation energy. What can you say about their reaction rates? Assume that temperature and reactant concentration are the same in both reactions.
06. Give the definitions for heterogeneous and homogeneous catalysts.
07. A student is studying the rate of the following chemical reaction:
C
2
H
4
O + NaOH -> H
2
O + NaC
2
H
3
O
Knowing that this is an exothermic reaction, he is measuring the rate of the reaction by timing how quickly the reaction vessel heats up. He notices that if he adds HCl to this reaction, the rate increases dramatically. He also determines that the HCl is being used up during the reaction. Is the HCl catalyst for this reaction?
08. A chemist does a rate analysis on the following reaction:
C
3
H
6
Br
2
+ 3I- -> C
3
H
6
+ 2Br- + 3I-
She gets the following data:
What is the rate equation for this reaction?
09. A chemist does a rate analysis on the following reaction:
2NO + I
2
-> 2NOI
He gets the following data:
What is the rate equation for this reaction?
10. Experiment tells us that the following reaction:
CH
3
OH + KF -> KOH + CH
3
F
is first order with respect to each of its reactants. We also know that the rate constant for this reaction is equal to 0.0123
at 10 °C. What is the instantaneous rate for this reaction at 10 ° C if the initial concentration of CH
3
OH is 0.59 M and the initial concentration of KF is 1.22M?
11. A certain chemical equation has three reactants. According to experiment, it is first order with respect to one of the reactants and second order with respect to each of the other 2 reactants. What is the overall order of the reaction?
12. A chemist runs a reaction at 50 deg;C. and determines its rate to be 0.00451
. If she increases the temperature to 80 °C., what will the rate of the reaction be?
13. A chemist runs a reaction at 25 °C. and determines that the reaction proceeds too quickly. He decides that the reaction needs to be slowed down by a factor of 4. At what emperature should he run the reaction?
14. Two of the following potential energy diagrams are for the same reaction. One represents the reaction with a catalyst, and one represents the reaction without a catalyst. The third diagram is for a completely different reaction. Identify the two diagrams that represent the same reaction and determine which one includes the effect of a catalyst.
15. Identify the catalyst in the following mechanism:
Step 1.
Ce
4+
+ Mn
2+
-> Ce
3+
+ Mn
3+
Step 2.
Ce
4+
+ Mn
3+
-> Ce
3+
+ Mn
4+
Step 3.
Mn
4+
+ Tl
+
-> Tl
3+
+ Mn
2+