Name ______Date______
AP Chemistry Final Exam Review Ch 5-
1.For a particular process q = 20 kJ and w = 15 kJ. Which of the following statements is true?
A)Heat flows from the system to the surroundings.
B)The system does work on the surroundings.
C)E = 35 kJ.
D)All of the above are true.
E)None of the above are true.
2.A 25.0 g piece of aluminum (which has a molar heat capacity of 24.03J/°Cmol) is heated to 82.4°C and dropped into a calorimeter containing water (specific heat capacity of water is 4.18J/g°C) initially at 22.3°C. The final temperature of the water is 24.9°C. Calculate the mass of water in the calorimeter.
A)118 g
B)6.57 g
C)3180 g
D)2120 g
E)none of these
3.You take 200. g of a solid at 30.0°C and let it melt in 400. g of water. The water temperature decreases from 85.1°C to 30.0°C. Calculate the heat of fusion of this solid.
A)125 J/g
B)285 J/g
C)461 J/g
D)518 J/g
E)cannot without the heat capacity of the solid
4.Consider the reaction:
C2H5OH(l) + 3O2(g) 2CO2(g) + 3H2O(l); H = –1.37 x 103 kJ
Consider the following propositions:
I. The reaction is endothermic
II. The reaction is exothermic.
III. The enthalpy term would be different if the
water formed was gaseous.
Which of these propositions is (are) true?
A)I
B)II
C)III
D)I, II
E)II, III
5.Given the heats of the following reactions:
H° (kJ)
I.P4(s) + 6Cl2(g) 4PCl3(g)-1225.6
II.P4(s) + 5O2(g) P4O10(s)–2967.3
III.PCl3(g) + Cl2(g) PCl5(g)–84.2
IV.PCl3(g) + (1/2)O2(g) Cl3PO(g)–285.7
Calculate the value of H° for the reaction below:
P4O10(s) + 6PCl5(g) 10Cl3PO(g)
A)–110.5 kJ
B)–610.1 kJ
C)–2682.2 kJ
D)–7555.0 kJ
E)None of these is within 5% of the correct answer.
6.The heat combustion of acetylene, C2H2(g), at 25°C, is –1299 kJ/mol. At this temperature, Hfo values for CO2(g) and H2O(l) are –393 and –286 kJ/mol, respectively. Calculate for Hfo acetylene.
A)2376 kJ/mol
B)625 kJ/mol
C)227 kJ/mol
D)–625 kJ/mol
E)none of these
15.In which groups do all the elements have the same number of valence electrons?
A)P, S, Cl
B)Ag, Cd, Ar
C)Na, Ca, Ba
D)P, As, Se
E)none
17.List the following atoms in order of increasing ionization energy: Li, Na, C, O, F.
A)Li < Na < C < O < F
B)Na < Li < C < O < F
C)F < O < C < Li < Na
D)Na < Li < F < O < C
E)Na < Li < C < F < O
19.Which of the following statements is incorrect?
A)Ionic bonding results from the transfer of electrons from one atom to another.
B)Dipole moments result from the unequal distribution of electrons in a molecule.
C)The electrons in a polar bond are found nearer to the more electronegative element.
D)A molecule with very polar bonds can be nonpolar.
E)Linear molecules cannot have a net dipole moment.
20.Atoms having greatly differing electronegativities are expected to form:
A)no bonds
B)polar covalent bonds
C)nonpolar covalent bonds
D)ionic bonds
E)covalent bonds
21.Atoms with very similar electronegativity values are expected to form
A)no bonds.
B)covalent bonds.
C)triple bonds.
D)ionic bonds.
E)none of these
22.For the elements Rb, F, and O, the order of increasing electronegativity is:
A)Rb < F < O
B)Rb < O < F
C)O < F < Rb
D)F < Rb < O
E)None of these
23.Select the molecule among the following that has a dipole moment.
A)CO2
B)SeO3
C)XeF4
D)SF4
E)BeCl2
24.Which of the following molecules has a dipole moment?
A)BCl3
B)SiCl4
C)PCl3
D)Cl2
E)none of these
25.Which of the following molecules has no dipole moment?
A)CO2
B)NH3
C)H2O
D)all
E)none
26) Draw the Lewis structures & determine the molecular shape of each of the molecules below.
a) BH3c) SF6
b) NO2d) PCl5
27.In the molecule C2H4 the valence orbitals of the carbon atoms are assumed to be
A)not hybridized.
B)sp hybridized.
C)sp2 hybridized.
D)sp3 hybridized.
E)dsp hybridized.
28.The hybridization of the central atom in SeF4 is:
A)sp
B)sp2
C)sp3
D)dsp3
E)d2sp3
29.The hybridization of the central atom in KrF4O is:
A)sp
B)sp2
C)sp3
D)dsp3
E)d2sp3
30.The hybridization of Br in BrF3 is
A)sp
B)sp2
C)sp3
D)dsp3
E)d2sp3
31.The following reaction occurs in basic solution:
F2 + H2O O2 + F–
When the equation is balanced, the sum of the coefficients is:
A)10
B)11
C)12
D)13
E)none of these
32.When the equation for the following reaction in basic solution is balanced, what is the sum of the coefficients?
MnO2 + HO2- MnO4–
A)11
B)31
C)14
D)9
E)18
33.The reaction below occurs in basic solution. In the balanced equation, what is the sum of the coefficients?
Zn + NO3– Zn(OH)42– + NH3
A)12
B)15
C)19
D)23
E)27
34.How many electrons are transferred in the following reaction?
SO32–(aq) + MnO4–(aq) SO42–(aq) + Mn2+(aq)
A)6
B)2
C)10
D)4
E)3
Use the following to answer questions 35 – 41
The standard reduction potentials are as follows:
MnO4– + 8H+ + 5e– Mn2+ + 4H2OE° = 1.51 V
Cr2O72– +14H+ + 5e– 2 Cr3+ +7H2OE° = 1.33 V
35.When current is allowed to flow, which species is oxidized?
A)Cr2O72–
B)Cr3+
C)MnO4–
D)Mn2+
E)H+
36.When current is allowed to flow, which species is reduced?
A)Cr2O72–
B)Cr3+
C)MnO4–
D)Mn2+
E)H+
37.What is the value of E°cell?
A)–0.18 V
B)2.84 V
C)0.18 V
D)1.79 V
E)2.29 V
38.What is the oxidation state of Cr in Cr2O72–?
A)+7
B)+6
C)+12
D)–1
E)–2
39.In which direction do electrons flow in the external circuit?
A)left to right
B)right to left
C)no current flows; the cell is at equilibrium
41.Calculate G for the rxn.
Use the following to answer 42 & 43.
Consider an electrochemical cell with a cobalt electrode immersed in 1.0M Co2+ and a lead electrode immersed in 1.0M Pb2+.
Co2+ + 2e– CoE° = –0.28 V
Pb2+ + 2e– PbE° = –0.13 V
42.Calculate E° for this cell
A)–0.15 V
B)0.15 V
C)–0.41 V
D)0.41 V
E)none of these
43.Which of the electrodes is the cathode?
A)The cobalt electrode.
B)The lead electrode.
44.The galvanic cell described by Zn(s) | Zn2+(aq) || Cu2+(aq) | Cu(s) has a standard cell potential of 1.101 volts. Given that Zn(s) Zn2+(aq) + 2e– has an oxidation potential of 0.762 volts, determine the reduction potential for Cu2+.
A)–1.863 V
B)1.863 V
C)–0.339 V
D)0.339 V
E)none of these
45.Choose the correct statement given the following information:
Fe3+(aq) + e– Fe2+(aq)E° = 0.77 volt
Fe(CN)63– + e– Fe(CN)64-E° = 0.36 volt
A)Fe2+(aq) is more likely to be oxidized than Fe2+ complexed to CN–.
B)Fe3+(aq) is more likely to be reduced than Fe3+ complexed to CN–.
C)Both a and b are true.
D)Complexation of Fe ions with CN– has no effect on their tendencies to become oxidized or reduced.
E)None of these is true.
47. Of Sn2+, Ag+, and/or Zn2+, which could be reduced by Cu?
A)Sn2+
B)Ag+
C)Zn2+
D)Two of them could be reduced by Cu.
E)All of them could be reduced by Cu.
48.Which of the following is the best reducing agent?
A)Cl2
B)H2
C)Mg
D)Mg2+
E)Cl–
ANSWERS NEXT PG
1)c 2)a 3)c 4)e 5)b 6)c 7 15)e 17)b 19)e 20)d 21)b 22)b 23)d 24)c 25)a 26)
27)c 28)d 29)e 30)d 31)d 32)a 33)c 34)c 35)b 36)c 37)c 38)b 39)a 41)86850 42)b 43)b 44)d 45)b 47)b 48)c