Chemistry 167 SI EXAM REVIEW 3
1. Which illustration best depicts how a catalyst works?
2. The synthesis of a copolymer with one continuous “core” strand of the first monomer with
attached strands of the second monomer creates a(n):
(A)alternating (B) block
3.
(C) graft
(D) random
Which process decreases the entropy of the system?
(A) 2H2O2(l)
2H2O(l) + O2(g)
(B) Cl2(g) + 2NO(g)
2NOCl(g)
(C) SiCl4(s)
Si(s) + 2Cl2(g)
(D) FeCl2(s) + H2(g)
Fe(s) + 2HCl(g)
4.
If the ΔH for the polymerization reaction of a polymer is –79.0 kJ/mol and the ΔS for that
process is –108 J/mol⋅K, at what temperature would depolymerization become feasible?
(A)730 K
(B) 480 K
(C) 275 K
(D) 8530 K
5. Which chemical will have a heat of formation of 0?
(A) Na(g)
(B) O(g)
(C) P(g)
(D) Xe(g)
6. What characteristic of a catalyst indicates its ability to catalyze a large number of reactions
over some length of time:
(A) its rate law
(C) its turnover number
(B) its homogeneity
(D) its activation energy
7. For a reaction of A
products, what is the order of the reaction if the plot of ln[A] vs.
time is linear and what does the slope of the line tell us?
(A) 1st, –k
(B) 1st , –Ea/R
(C) 2nd , 1 / [A]0
(D) 2nd , k
Chemistry 167 SI EXAM REVIEW 3
8. Why do snowflakes form spontaneously only at low temperatures?
(A) because ΔH>0 and ΔS<0 for the formation of a snowflake.
(B) because ΔH>0 and ΔS>0 for the formation of a snowflake.
(C) because ΔH<0 and ΔS<0 for the formation of a snowflake.
(D) because ΔH<0 and ΔS>0 for the formation of a snowflake.
9. In the phase diagram to the right, what happens along the line (shown with arrow)?
(A) gas is heated
(C) gas becomes solid
(B) liquid is heated
(D) liquid become solid
10. The additional of a catalyst in a chemical reaction
a. lowers the enthalpy change in the overall reaction
b. increases the final concentration of products
c. increases the fraction of molecules with a given kinetic energy
d. provides an alternative path with a different activation energy
11. Calculate the packing efficiency of Face centered cubic cell (Show all work)
12. Copper wires heat up because of resistance in the wire. If a 140.0 g wire
initially at 25.4 oC gains 295 J of energy as heat, what is the final temperature of the
wire? (Copper has a specific heat of 0.384 J/goC)
Chemistry 167 SI EXAM REVIEW 3
13. (8 pts) Given these data, calculate the free energy change for the reaction of MnO
with O2(g) to form Mn3O4.
14. The table below gives data for the rate of the reaction,
2HgCl2(aq) + C2O42–(aq)
2Cl–(aq) + 2CO2(g) + Hg2Cl2(s).
Determine the rate law and calculate the rate constant, k.
[HgCl2] (M) [C2O42–] (M) Rate, mol / L⋅s
0.10
0.10
1.3 x 10-7
0.10
0.20
5.2 x10-7
0.20
0.20
10 x 10-7
Chemistry 167 SI EXAM REVIEW 3
15. The table shows initial rate data for the given reaction. Write the rate law and calculate the
rate constant (with correct units).
SO2 + 2Cl2
SOCl2 + CL2O
Chemistry 167 SI EXAM REVIEW 3