2) place the following in order of decreasing dipole moment
I. cis-CHCl=CHCl II. trans-CHCl=CHCl III. cis-CHF=CHF
A) III > I > II
B) II > I > III
C) I > III > II
D) II > III > I
E) I = III > II
A. The trans dichloroethane actually cancels itself out and has 0 dipole moment. Then for the cis flourine, it has higher dipole moment than I, so A.
3) Give the hybridization for the O in OF2
A) sp
B) sp3
C) sp2
D) sp3d
E) sp3d2
Answer: B. To get this, draw the lewis structure for OF2. Then count the lone pairs and the number of atoms bonded to O. This is the steric number. if the steric number is 4, the atom is sp3, if it's 3 -> sp2, if it's 2 -> sp
4) Give the hybridization for the S in SO3
A) sp
B) sp3
C) sp2
D) sp3d
E) sp3d2
Answer: C. To get this, draw the lewis structure for SO3. Then count the lone pairs and the number of atoms bonded to S. This is the steric number. if the steric number is 4, the atom is sp3, if it's 3 -> sp2, if it's 2 -> sp
5) How many of the following molecules have sp2 hybridization on the central atom?
HCN SO2 OCl2 XeCl2
A) 4
B) 3
C) 2
D) 1
E) 0
Answer: D. To get this, draw the lewis structure for each molecule. Then count the lone pairs and the number of atoms bonded to the central atoms. This is the steric number. if the steric number is 4, the atom is sp3, if it's 3 -> sp2, if it's 2 -> sp
6) Give the hybridization for the C in C2F2
A) sp3d2
B) sp3d
C) sp3
D) sp2
E) sp
E. The lewis structure is linear because of the tripple bond between the two carbon atoms. Linear = sp
7) How many p-orbitals participate in the Molecular orbitals in Benzene and how many MOs does this give?
A) 0
B) 2
C) 4
D) 6
E) 12
D
8) A chemical change
A) occurs when methane gas is burned.
B) occurs when paper is shredded.
C) occurs when water is vaporized.
D) occurs when salt is dissolved in water.
E) occurs when powdered lemonade is stirred into water.
A
9) What is the stoichiometric coefficient for oxygen?
B2H6(g) + O2(g) -> B2O3(s) + H2O(g)
What is the stoichiometric coefficient for oxygen?
A) 1
B) 2
C) 3
D) 4
E) 6
C
10) Balance the following equation with the smallest whole number coefficients. Choose the answer that is the sum of the coefficients in the balanced equation. Do not forget coefficients of “one.”
Cr2(SO4)3 + RbOH -> Cr(OH)3 + Rb2SO4
A) 10
B) 12
C) 13
D) 14
E) 15
B
11) What is the percent yield of C2H2 if 62.80 g of water yields 15.38 g of C2H2 using the following equation.
CaC2(s) + 2 H2O(l) → Ca(OH)2(aq) + C2H2(g)
A) 13.84%
B) 33.90%
C) 91.47%
D) 48.10%
E) 68.52%
B
12) Determine the percent yield of a reaction that produces 28.65 g of Fe when 50.00 g of Fe2O3 react with excess Al to produce aluminum oxide and Fe. (Al: 26.98, Fe: 55.85)
A) 61.03 %
B) 28.65 %
C) 57.30 %
D) 20.02 %
E) 81.93 %
E
13) In the reaction of Zn with hydrochloric acid (HCl) to give zinc(II) chloride and hydrogen, 25.0 grams of Zn have reacted with 17.5 g of HCl. How many grams of H2 will be produced? (Zn: 65.38, Cl: 35.45)
A) 0.385 g H2
B) 0.484 g H2
C) 0.765 g H2
D) 25.0 g H2
Answer: B
14) According to the following reaction, what amount of Al2S3 remains when 20.00 g of Al2S3 and 2.00 g of H2O are reacted? A few of the molar masses are as follows: Al2S3 = 150.17 g/mol, H20 = 18.02 g/mol.
Al2S3 + 6H2O -> 2Al(OH)3 + 3H2S
A) 0 g
B) 14.00 g
C) 8.33 g
D) 19.78 g
E) 17.22 g
Answer: E
15) Two samples of calcium and fluoride are decomposed into their constituent elements. The first sample showed that the yield of products was 100% (really!). If the second sample produced 294 mg of fluorine, how many g of calcium were formed? (Ca: 40.08, F: 19.00)
A) 0.280 g
B) 3.10 * 10^2 g
C) 3.13 g
D) 0.310 g
E) 2.80 * 10^2 g
D
16) Determine the molarity of a solution formed by dissolving 97.7 g LiBr in enough water to yield 750.0 mL of solution. (Li: 6.941, Br: 79.90)
A) 1.50 M
B) 1.18 M
C) 0.130 M
D) 0.768 M
E) 2.30 M
A
17) What is the concentration of HCl in the final solution when 65 mL of a 9.0 M HCl solution is diluted with pure water to a total volume of .15 L?
A) 2.1 × 10-2 M
B) 3.9 M
C) 21 M
D) 3.9 × 10^3 M
B
18) How many molecules of sucrose (C12H22O11, molar mass = 342.30 g/mol) are contained in 14.3 mL of 0.140 M sucrose solution
A) 8.29 * 10^22 molecules C12H22O11
B) 1.21 * 10^21 molecules C12H22O11
C) 6.15 * 10^22 molecules C12H22O11
D) 1.63 * 10^23 molecules C12H22O11
E) 5.90 * 10^24 molecules C12H22O11
B
19) What volume of 0.244 M KCl solution is required to react exactly with 50.0 mL of 0.210 M PB(NO3)2 solution?
A) 97.4 mL
B) 116 mL
C) 43.0 mL
D) 86.1 mL
E) 58.1 mL
D
20) Which of the following will have the highest electrical conductivity?
A) 0.045 M Al2(SO4)3
B) 0.050 M (NH4)2CO3
C) 0.10 M NaBr
D) 0.10 M Kl
E) 0.10 M KF
A
21) K2SO4 is soluble
True
False
True
22) Ba2SO4 is soluble
True
False
False
23) NH4CO3 is slightly soluble
True
False
False (It's very soluble)
24) Ba(OH)2 is slightly soluble
True
False
True
25) Ni(II)I2 is soluble
True
False
True
26) Which pair of compounds is soluble in water?
A) Hg2Cl2 and HgBr2
B) NiS and Li2S
C) NH4I and Ni(NO3)2
D) LiNO3 and CuCO3
C
27) Give the complete ionic equation for the reaction (if any) that occurs when aqueous solutions of lithium sulfide and copper (II) nitrate are mixed.
31) The titration of 25.0 mL of an unknown concentration of H2SO4 solution requires 83.6 mL of 0.12 M LiOH solution. What is the concentration of the H2SO4 solution?
A) 0.20 M
B) 0.40 M
C) 0.10 M
D) 0.36 M
E) 0.25 M
A
32) The titration of 80.0 mL of an unknown concentration of H3PO4 solution requires 126 mL of .218 M KOH solution. What is the concentration of H3PO4 solution (in M)
A) 1.03 M
B) 0.343 M
C) 0.114 M
D) 0.138 M
E) 0.0461 M
C
33) Determine the oxidation state of nitrogen in NO2
A) +5
B) +3
C) 0
D) +2
E) +4
E
34) What element is undergoing reduction (if any) in the following reaction?
Zn(s) + 2AgNO3(aq) -> Zn(NO3)2(aq) + 2 Ag(s)
A) Zn
B) N
C) O
D) Ag
E) This is not an oxidation-reduction reaction
D
35) Which choice gives the correct oxidation numbers for all three elements in Rb2SO3 in the order that the elements are shown in the formula?
A) -2, +6, -2
B) -1, +4, -3
C) +2, +4, -2
D) +1, +4, -2
E) +1, +6, -6
D
36) Which of the following signs on q and w represent a system that is doing work on the surroundings, as well as gaining heat from the surroundings?
A) q = +, w = -
B) q = -, w = +
C) q = +, w = +
D) q = -, w = -
E) None of these represent the system referenced
A
37) Which of the following signs on q and w represent a system that the surroundings are doing work on, as well as gaining heat from the surroundings?
A) q = +, w = -
B) q = -, w = +
C) q = +, w = +
D) q = -, w = -
E) None of these represent the system referenced
C
38) How many of the following molecules are polar?
PCl5 COS XeO3 SeBr2
A) 2
B) 0
C) 1
D) 3
E) 4
D
39) When an aqueous solution of manganese (II) nitrate is combined with an aqueous solution of ammonium sulfide,
what should precipitate out?
A) MnS
B) Mn(SO3)2
C) Mn(SO4)2
D) Mn2SO3
E) Mn2SO4
Answer: A. Sulfides accept for sodium. Sulfide is 2- so it just goes into the Mn.
40) Give the net ionic equation for the reaction (if any) that occurs when aqueous solutions of K2S and Fe(NO3)2 are mixed.
45) Determine the theoretical yield of HCl if 60.0 g of BCl3 and 37.5 g of H2O are reacted according to the following balanced reaction. (molar mass of BCl3 = 117.16 g/mol, B: 10.81, Cl:35.45, O:15.999, H:1.0079)