Name ________________
Kinetics Practice Exam
Date:_________________
1. As the number of effective collisions between reacting particles increases, the rate of reaction
1) decreases
2) increases
3) remains the same
2. A piece of Mg(s) ribbon is held in a Bunsen burner flame and begins to burn according to the equation:
2Mg(s) + O2 (g) ® 2MgO(s).
The reaction begins because the reactants
1)
2)
3)
4)
are activated by heat from the Bunsen burner flame
are activated by heat from the burning magnesium
underwent an increase in entropy
underwent a decrease in entropy
3. As the temperature increases, the rate of an exothermic reaction
1) decreases
2) increases
3) remains the same
4. Which conditions will increase the rate of a chemical reaction?
1)
2)
3)
4)
decreased temperature and decreased concentration of reactants
decreased temperature and increased concentration of reactants
increased temperature and decreased concentration of reactants
increased temperature and increased concentration of reactants
5. Four aluminum samples are each reacted with separate 1 M copper sulfate solutions under the same
conditions of temperature and pressure. Which aluminum sample would react most rapidly?
1) 1 gram bar of Al
2) 1 gram of Al ribbon
3) 1 gram of Al pellets
4) 1 gram of Al powder
6. Given the balanced equation representing a phase change:
C6H4Cl 2(g)
C6H4Cl 2(s) + energy
Which statement describes this change?
1) It is endothermic, and entropy decreases.
3) It is exothermic, and entropy decreases.
2) It is endothermic, and entropy increases. 4) It is exothermic, and entropy increases.
7. Which will occur if a catalyst is added to a reaction mixture?
1)
2)
3)
4)
The activation energy will be changed.
Only the rate of the forward reaction will be increased.
Only the rate of the reverse reaction will be increased.
The energy change ( DH) of the reaction will be decreased.
Chemistry!
Kinetics Practice Quiz
8. When a substance was dissolved in water, the temperature of the water decreased. This process is described
as
1)
2)
3)
4)
endothermic, with the release of energy
endothermic, with the absorption of energy
exothermic, with the release of energy
exothermic, with the absorption of energy
9. Given the reaction:
Fe + S ® FeS + energy
Which statement about this reaction is true?
1)
2)
3)
4)
It is endothermic.
It is exothermic.
The potential energy of the reactants is lower than the potential energy of the product.
The potential energy of the reactants is the same as the potential energy of the product.
10. Which reaction releases the greatest amount of energy per 2 moles of product?
1) 2CO(g) + O 2(g) ® 2CO 2(g)
2) 4Al(s) + 3O 2(g) ® 2Al 2O 3(s)
3) 2H2(g) + O 2(g) ® 2H2O(g)
4) N2(g) + 3H 2(g) ® 2NH 3(g)
11. Given the balanced equation representing a reaction at 101.3 kPa and 298 K:
N2(g) + 3H 2(g)
2NH 3(g) + 91.8 kJ
Which statement is true about this reaction?
1) It is exothermic and H equals –91.8 kJ. 3) It is endothermic and
2) It is exothermic and H equals +91.8 kJ. 4) It is endothermic and
H equals –91.8 kJ.
H equals +91.8 kJ.
12. Given the reaction:
2 H2(g) + O 2(g)
2 H2O( ) + 571.6 kJ
What is the approximate H for the formation of 1 mole of H 2O( )?
1) –285.8 kJ
2) +285.8 kJ
3) –571.6 kJ
Chemistry!
4) +571.6 kJ
Kinetics Practice Quiz
13. The potential energy diagram below represents the reaction
2 KClO 3
2 KCl + 3 O 2.
Which numbered interval on the diagram would change when a catalyst is added?
1) 1
2) 2
3) 3
4) 4
14. Which interval on the potential energy diagram shown below represents the
a+b
1) 1
15.
H of the reaction
c + d?
2) 2
3) 3
4) 4
According to the potential energy diagram shown above, the chemical reaction in
the forward direction is
1) exothermic because it absorbs energy
2) exothermic because it releases energy
3) endothermic because it absorbs energy
4) endothermic because it releases energy
Chemistry!
Kinetics Practice Quiz
16. In the potential energy diagram below, which letter represents the potential energy of the activated
complex?
1) A
2) B
3) C
4) D
17. Which diagram represents the potential energy of an exothermic reaction?
1)
2)
3)
4)
18. The graph below represents the potential energy changes that occur in a chemical reaction. Which letter
represents the activated complex?
1) A
2) B
3) C
4) D
19. Given the balanced equation representing a reaction:
CH4(g) + 2O2(g) ® 2H2O(g) + CO2(g) + heat
Which statement is true about energy in this reaction?
1)
2)
3)
4)
The reaction is exothermic because it releases heat.
The reaction is exothermic because it absorbs heat.
The reaction is endothermic because it releases heat.
The reaction is endothermic because it absorbs heat.
Chemistry!
Kinetics Practice Quiz
20. Which change is exothermic?
1) freezing of water
2) melting of iron
3) vaporization of ethanol
4) sublimation of iodine
21. As the reactants are converted to product in the reaction
A(g) + B(g) ® C(s),
the entropy of the system
1) decreases
2) increases
3) remains the same
22. Which chemical reaction will always be spontaneous?
1)
2)
3)
4)
an exothermic reaction in which entropy decreases
an exothermic reaction in which entropy increases
an endothermic reaction in which entropy decreases
an endothermic reaction in which entropy increases
Chemistry!
Answer Key
Kinetics Practice Quiz
1.
2
2.
1
3.
2
4.
4
5.
4
6.
2
7.
1
8.
2
9.
2
10.
2
11.
1
12.
1
13.
2
14.
2
15.
3
16.
2
17.
4
18.
2
19.
1
20.
1
21.
1
22.
2
Chemistry!