108-1st Chem Exam (B)
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) 1.55 kg/m3 is equivalent to ________ g/L.
A) 1.55 × 10-3 B) 1.55 × 106 C) 1.55 × 103 D) 1.55 E) 1.55 × 10-6 Answer: D
2) The correct result (indicating the proper number of significant figures) of the following problem is ________.
(0.002843) (12.80184) 0.00032
A) 1.1 × 102 B) 113.736 C) 113.7 D) 113.73635 E) 113.74
Answer: A
3) There should be ________ significant figures in the answer to the following computation.
(10.07 + 7.395) 2.5
A) 1 B) 2 C) 3 D) 4 E) 5
Answer: B
4) Which one of the following is an extensive property?
A) boiling point B) density C) volume D) freezing point
E) temperature Answer: C
5) A student performs an experiment to determine the density of a sugar solution. She obtains the following results: 1.71 g/mL, 1.73 g/mL, 1.67 g/mL, 1.69 g/mL. If the actual value for the density of the sugar solution is 1.40 g/mL, which statement below best describes her results?
A) Her results are precise, but not accurate.
B) Her results are accurate, but not precise.
C) Her results are both precise and accurate D) Her results are neither precise nor accurate.
E) It isn't possible to determine with the information given.
Answer: A
6) Which of the following are combination reactions?
1) CH4 (g) + O2 (g) CO2 (g) + H2O (l) 2) CaO (s) + CO2 (g) CaCO3 (s) 3) Mg (s) + O2(g) MgO (s) 4) PbCO3 (s) PbO (s) + CO2 (g)
A) 4 only B) 2 and 3 C) 1, 2, 3, and 4 D) 1, 2, and 3 E) 2, 3, and 4 Answer: B
7) Which of the following are combustion reactions?
1) CH4 (g) + O2 (g) CO2 (g) + 2H2O (l) 2) CaO (s) + CO2 (g) CaCO3 (s) 3) PbCO3 (s) PbO (s) + CO2 (g)
4) CH3OH (l) + O2 (g) CO2 (g) + 2H2O (l)
A) 1, 3, and 4 B) 1 and 4 C) 1, 2, 3, and 4 D) 2, 3, and 4 E) 3 and 4 Answer: B
8) Which of the following are decomposition reactions?
1) CH4 (g) + O2 (g) CO2 (g) + H2O (l) 2) CaO (s) + CO2 (g) CaCO3 (s) 3) Mg (s) + O2(g) MgO (s) 4) PbCO3 (s) PbO (s) + CO2 (g)
A) 1, 2, and 3 B) 1, 2, 3, and 4 C) 2, 3, and 4 D) 4 only E) 2 and 3 Answer: D
9)How many oxygen atoms are contained in 2.74 g of Al2(SO4)3?
A) 8.01 × 10-3 B) 12 C) 7.22 × 1024 D) 5.79 × 1022 E) 6.02 × 1023 Answer: D
10) A nitrogen oxide is 63.65% by mass nitrogen. The molecular formula could be ________.
A)N2O B)N2O4 C) NO D)NO2
E)either NO2 or N2O4 Answer: A
11)When the following equation is balanced, the coefficient of H2S is ________.
FeCl3 (aq) + H2S (g) Fe2S3 (s) + HCl (aq)
A) 3 B) 5 C) 4 D) 2 E) 1
Answer: A
12)Calculate the percentage by mass of carbon in CO2.
A) 75.10 B) 72.71 C) 73.05 D) 27.29 E) 37.53
Answer: D
13)A 1.038 g sample of unknown containing C, H, and O yielded 2.48 g of CO2 and 0.510 g of H2O during combustion analysis. Determine the empirical formula of the compound.
A)CH3O B)C2H6O2 C)C3H3O D)C6H6O2 E)C6H6O
Answer: C
14)Under appropriate conditions, nitrogen and hydrogen undergo a combination reaction to yield ammonia:
N2 (g) + 3H2 (g) 2NH3 (g)
If the reaction yield is 81.4 %, how many moles of N2 are needed to produce 8.50 mol of NH3 when H2 is excess in this reaction?
A) 5.22 B) 15.7 C) 10.4 D) 6.92 E) 20.9
Answer: A
15)Sulfur and fluorine react in a combination reaction to produce sulfur hexafluoride:
S (s) + 3F2(g) SF6 (g)
The maximum amount of SF6 that can be produced from the reaction of 32.1 g of sulfur with 114 g of fluorine is ________ g.
A) 219 B) 438 C) 584 D) 146 E) 48.7
Answer: D
16) What is the empirical formula of a compound that contains 29% Na, 41% S, and 30% O by mass?
A)Na2S2O3 B)NaSO3 C) NaSO D)Na2S2O6 E)NaSO2
Answer: A
17) A molecule of water contains hydrogen and oxygen in a 1:8 ratio by mass. This is a statement of ________.
A) the law of conservation of mass B) the law of conservation of energy C) the law of multiple proportions D) the law of constant composition
E) none of the above Answer: D
18) Which of the following atoms has the smallest number of neutrons?
A) carbon-12 B) carbon-13 C) chlorine-35 D) carbon-14 E) bromine-79 Answer: A
19) Which one of the following is not true concerning cathode rays?
A) They travel in straight lines in the absence of electric or magnetic fields.
B) They originate from the negative electrode.
C) They impart a negative charge to metals exposed to them.
D) The characteristics of cathode rays depend on the material from which they are emitted.
E) They are made up of electrons.
Answer: D
20) Silver has two naturally occurring isotopes with the following isotopic masses:
10747 Ag 107 47 Ag 106.90509 108.9047
21) The charge on an electron was determined in the ________.
A) cathode ray tube, by J. J. Thomson B) atomic theory of matter
C) Rutherford gold foil experiment D) Dalton atomic theory
E) Millikan oil drop experiment Answer: E
22) In the Rutherford nuclear-atom model, ________.
A) mass is spread essentially uniformly throughout the atom
B) the heavy subatomic particles, protons and neutrons, reside in the nucleus C) the light subatomic particles, protons and neutrons, reside in the nucleus
D) the three principal subatomic particles (protons, neutrons, and electrons) all have essentially the same mass
E) the three principal subatomic particles (protons, neutrons, and electrons) all have essentially the same mass and mass is spread essentially uniformly throughout the atom
Answer: B
23) Which combination of protons, neutrons, and electrons is correct for the isotope of copper, 6329Cu?
A) 63 p+, 29 n°, 63 e- B) 34 p+, 29 n°, 34 e- C) 29 p+, 29 n°, 63 e- D) 29 p+, 34 n°, 29 e- E) 34 p+, 34 n°, 29 e- Answer: D
24) Elements ________ exhibit similar physical and chemical properties.
A) with similar atomic masses
B) on opposite sides of the periodic table C) with similar chemical symbols
D) in the same group of the periodic table E) in the same period of the periodic table Answer: D
25) Of the choices below, which one is not an ionic compound?
A)MoCl6 B) NaCl C)PCl5 D)PbCl2 E) RbCl
Answer: C
26) Which formula/name pair is incorrect?
A)Mg3N2 magnesium nitrite
B)Mg(MnO4)2 magnesium permanganate C)Mn(NO2)2 manganese(II) nitrite D)Mn(NO3)2 manganese(II) nitrate
E)Mg(NO3)2 magnesium nitrate Answer: A
27) Methane and ethane are both made up of carbon and hydrogen. In methane, there are 12.0 g of carbon for every 4.00 g of hydrogen, a ratio of 3:1 by mass. In ethane, there are 24.0 g of carbon for every 6.00 g of hydrogen, a ratio of 4:1 by mass. This is an illustration of the law of ________.
A) multiple proportions B) octaves
C) conservation of mass D) conservation of matter
E) constant composition Answer: A
28) When aqueous solutions of ________ are mixed, a precipitate forms.
A) NaI and KBr B)NiBr2 and AgNO3 C)K2SO4 and CrCl3 D)Li2CO3 and CsI
E)KOH and Ba(NO3)2 Answer: B
29) The net ionic equation for the reaction between aqueous sulfuric acid and aqueous sodium hydroxide is ________.
A) SO42- (aq) + 2Na+ (aq) 2Na+ (aq) + SO42-(aq)
B) 2H+ (aq) + SO42- (aq) + 2Na+ (aq) + 2OH- (aq) 2H2O (l) + 2Na+ (aq) + SO42- (aq) C) H+ (aq) + HSO4- (aq) + 2Na+ (aq) + 2OH- (aq) 2H2O (l) + 2Na+ (aq) + SO42-(aq) D) 2H+ (aq) + OH- (aq) H2O( l)
E) H+ (aq) + HSO4- (aq) + 2OH- (aq) 2H2O (l) + SO42- (aq) Answer: D
30) Which one of the following is a triprotic acid?
A) chloric acid B) hydrofluoric acid C) sulfuric acid D) phosphoric acid
E) nitric acid Answer: D
31)What are the spectator ions in the reaction between KOH (aq) and HNO3 (aq)?
A) H+ and NO3- B) OH- only C) H+ and OH- D) K+ and H+
E) K+ and NO3- Answer: E
32) In which reaction does the oxidation number of oxygen increase?
A)2H2O (l) 2H2 (g) + O2 (g)
33) Which solution contains the largest number of moles of chloride ions?
A)7.50 mL of 0.500 M FeCl3 B) 25.00 mL of 0.400 M KCl C) 4.00 mL of 1.000 M NaCl D)30.00 mL of 0.100 M CaCl2
E)10.0 mL of 0.500 M BaCl2 Answer: A
34)A 0.355 M K2SO4 solution can be prepared by ________.
A)dissolving 46.7 g of K2SO4 in water and diluting to a total volume of 250.0 mL B)dilution of 1.00 mL of 0.355 M K2SO4 to 1.00 L
C)diluting 46.7 mL of 1.90 M K2SO4 solution to 250.0 mL
D)dissolving 46.7 g of K2SO4 in water and diluting to 500.0 mL, then diluting 25.0 mL of this solution to a total volume of 500.0 mL
E)dilution of 500.0 mL of 1.00 M K2SO4 to 1.00 L Answer: C
35) Which of these metals is the most easily oxidized?
A) Li B) Cu C) Au D) Pt E) Hg
Answer: A
36) Oxidation is the ________ and reduction is the ________.
A) loss of oxygen, gain of electrons B) gain of electrons, loss of electrons C) gain of oxygen, loss of mass D) loss of electrons, gain of electrons
E) gain of oxygen, loss of electrons Answer: D
37)The molarity of an aqueous solution containing 75.3 g of glucose (C6H12O6) in 35.5 mL of solution is ________.
A) 2.12 B) 11.8 C) 481 D) 0.0118 E) 14.8
Answer: B
38)Which hydroxides are strong bases?
Sr(OH)2 KOH NaOH Ba(OH)2 A)KOH, NaOH, Ba(OH)2
B) KOH, NaOH C)KOH, Ba(OH)2
D)Sr(OH)2, KOH, NaOH, Ba(OH)2 E) None of these is a strong base.
Answer: D
39)Which species is oxidized in the reaction below?
Au(s) + 3NO3-(aq) + 6H+(aq) Au3+(aq) + NO(g) + 3H2O (l)
A) H+ B) N+5 C) Au D) O2- E)H2O
Answer: C
40) If an unknown sample contains 39.04% sulfuric acid by mass, then a 0.9368 g of that sample would require ________ mL of 0.2389 M NaOH for neutralization.
A) 31.22 B) 15.61 C) 79.96 D) 39.98 E) 7.80
Answer: A
