Chem 116 ASU Final review Exam
Questions & Correct Verified
Answers| Already Passed
The effect of the catalyst on the reaction is to provide a different reaction mechanism
and reduce the activation energy of the reaction. The catalyst is recovered once the
reaction is completed.
Which of the following statements is true?
A catalyst lowers the change in enthalpy, ΔH, for a reaction by providing a different
reaction mechanism.
The catalyst does not participate in the chemical reaction.
The effect of the catalyst on the reaction is to provide a different reaction mechanism
and reduce the activation energy of the reaction. The catalyst cannot be recovered
once the reaction is completed.
The effect of the catalyst on the reaction is to provide a different reaction mechanism
and reduce the activation energy of the reaction. The catalyst is recovered once the
reaction is completed.
No. Intermediates in a chemical reaction can be present in very low concentrations.
If experiments show that during the decomposition of N2O, NO2 does not
accumulate in measurable quantities, does this rule out the proposed mechanism?
,Yes. All substances in a chemical reaction must be present in measurable amounts,
hence the proposed mechanism must be ruled out
No. Intermediates in a chemical reaction can be present in very low concentrations.
B
Consider a rate law of the form: rate = k[A]2. The total order of the reaction is 2.
Which elementary mechanism below is compatible with this rate law?
9.3 s
The rate constant for a particular reaction is 2.4 x 10 ⎻2 s −1 at 125°C. If the initial
concentration of reactant is 0.50 M, how long does it take for the concentration to
decrease to 0.40 M.
21 s
38 s
9.3
s
7.9 s
False
Is the following statement true or false? A catalyst does not participate in the chemical
reaction which is why it does not appear in the balanced net chemical equation.
,False
True
EA=270 kJ mol-1
What is the value of the activation energy for this reaction?
EA=190 kJ mol-1
EA=420 kJ mol-1
EA=270 kJ mol-1
Two
How many intermediate states can be identified in this reaction profile?
Three.
Two.
4.39 s
1.14 x 10-1 s
2.85 x 10-2 s
, 1.52 s
4.39 s
5.48x10-1 s
Approximately 6.0 h
What is the half-life of this radio-isotope?
Hint: You may need to make an appropriate graph and curve fit to determine the half-
life but if you understand the concept of half-life, you should be able to look at the table
data and available answers to come up with the answer.
Approximately 10.0 h
Approximately 18.0 h
Approximately 12.0 h
Approximately 6.0 h
Cl
Sc
Ti
Questions & Correct Verified
Answers| Already Passed
The effect of the catalyst on the reaction is to provide a different reaction mechanism
and reduce the activation energy of the reaction. The catalyst is recovered once the
reaction is completed.
Which of the following statements is true?
A catalyst lowers the change in enthalpy, ΔH, for a reaction by providing a different
reaction mechanism.
The catalyst does not participate in the chemical reaction.
The effect of the catalyst on the reaction is to provide a different reaction mechanism
and reduce the activation energy of the reaction. The catalyst cannot be recovered
once the reaction is completed.
The effect of the catalyst on the reaction is to provide a different reaction mechanism
and reduce the activation energy of the reaction. The catalyst is recovered once the
reaction is completed.
No. Intermediates in a chemical reaction can be present in very low concentrations.
If experiments show that during the decomposition of N2O, NO2 does not
accumulate in measurable quantities, does this rule out the proposed mechanism?
,Yes. All substances in a chemical reaction must be present in measurable amounts,
hence the proposed mechanism must be ruled out
No. Intermediates in a chemical reaction can be present in very low concentrations.
B
Consider a rate law of the form: rate = k[A]2. The total order of the reaction is 2.
Which elementary mechanism below is compatible with this rate law?
9.3 s
The rate constant for a particular reaction is 2.4 x 10 ⎻2 s −1 at 125°C. If the initial
concentration of reactant is 0.50 M, how long does it take for the concentration to
decrease to 0.40 M.
21 s
38 s
9.3
s
7.9 s
False
Is the following statement true or false? A catalyst does not participate in the chemical
reaction which is why it does not appear in the balanced net chemical equation.
,False
True
EA=270 kJ mol-1
What is the value of the activation energy for this reaction?
EA=190 kJ mol-1
EA=420 kJ mol-1
EA=270 kJ mol-1
Two
How many intermediate states can be identified in this reaction profile?
Three.
Two.
4.39 s
1.14 x 10-1 s
2.85 x 10-2 s
, 1.52 s
4.39 s
5.48x10-1 s
Approximately 6.0 h
What is the half-life of this radio-isotope?
Hint: You may need to make an appropriate graph and curve fit to determine the half-
life but if you understand the concept of half-life, you should be able to look at the table
data and available answers to come up with the answer.
Approximately 10.0 h
Approximately 18.0 h
Approximately 12.0 h
Approximately 6.0 h
Cl
Sc
Ti
