1071-1st Chem Exam-1071017(A)
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) The correct answer (reported to the proper number of significant figures) to the following is __________.
(2.05631)(6.9391136) / 12.59326 = _____
A) 1.133064 B) 1.1361 C) 1.13306 D) 1.1330639
E) none of the above Answer: C
2) In the following list, only __________ is not an example of a chemical reaction.
A) dissolution of a penny in nitric acid B) the rusting of iron
C) the formation of polyethylene from ethylene D) the condensation of water vapor
E) a burning candle Answer: D
3) An object will sink in a liquid if the density of the object is greater than that of the liquid. The mass of a sphere is 4.69 g. If the volume of this sphere is less than __________ cm3, then the sphere will sink in liquid mercury (density = 13.6 g/cm3).
A) 2.90 B) 7.48 C) 0.345 D) 1.08
E) none of the above Answer: C
4) A temperature of 300 K is the same as __________°F.
A) 351 B) 81 C) 63 D) 260 E) 711
Answer: B
5) _________is the abbreviation for the prefix "milli".
A) M B) k C) d D) m E) n
Answer: D
6) The number 1.00430 has __________ significant figures.
A) 6 B) 3 C) 4 D) 2 E) 5
Answer: A
7) The density of mercury is 13.6 g/cm3. The density of mercury is __________ kg/m3.
A) 1.36 × 104 B) 1.36 × 10-5 C) 1.36 × 10-4 D) 1.36 × 10-2 E) 1.36 × 108 Answer: A
8) The recommended adult dose of Elixophyllin , a drug used to treat asthma, is 6.00 mg/kg of body mass.
Calculate the dose in milligrams for a 115-lb person. 1 lb = 453.59 g.
A) 24 B) 1.5 C) 1,521 D) 3.1 × 105 E) 313
Answer: E
9) The correct answer (reported to the proper number of significant figures) to the following is __________.
(12.67 + 19.2)(3.99) / (1.36 + 11.366) = _____
A) 9.999 B) 9.9985 C) 1.00 x 101 D) 9.99851
E) none of the above Answer: E
10) There are __________ significant figures in the answer to the following computation:
(29.2 - 20.0) (1.79 × 105) 1.39
A) 1 B) 2 C) 3 D) 4 E) 5
Answer: B
11) Which of these metals is the least easily oxidized?
NaAu FeCa
AgA) Au B) Fe C) Na D) Ag E) Ca
Answer: A
12) Which one of the following is a triprotic acid?
A) chloric acid B) sulfuric acid C) phosphoric acid D) nitric acid
E) hydrofluoric acid Answer: C
13) Which combination will produce a precipitate?
A) Pb(NO3)2 (aq) and HCl (aq) B) Cu(NO3)2 (aq) and KC2H3O2 (aq) C) NaOH (aq) and Sr(NO3)2 (aq) D) AgC2H3O2 (aq) and HC2H3O2 (aq)
E) KOH (aq) and HNO3 (aq) Answer: A
14) Which of the following is insoluble in water at 25 °C?
A) (NH4)2CO3 B) Ca(OH)2 C) Na2S
D) Ba(C2H3O2)2 E) Mg3(PO4)2 Answer: E
15) What is the concentration (M) of CH3OH in a solution prepared by dissolving 11.7 g of CH3OH in sufficient water to give exactly 230. mL of solution?
A) 0.0841 B) 1.59 C) 11.9 D) 0.00159 E) 3.17
Answer: B
16) A stock solution of HNO3 is prepared and found to contain 13.5 M of HNO3. If 25.0 mL of the stock solution is diluted to a final volume of 0.500 L, the concentration of the diluted solution is __________ M.
A) 1.48 B) 0.270 C) 0.675 D) 270 E) 675
Answer: C
17) With which of the following will the potassium ion form an insoluble salt?
A) sulfate B) chloride C) carbonate
D) sulfate and carbonate E) none of the above Answer: E
18) Lead ions can be precipitated from aqueous solutions by the addition of aqueous iodide:
Pb2+ (aq) + 2I- (aq) PbI2 (s)
Lead iodide is virtually insoluble in water so that the reaction appears to go to completion. How many milliliters of 3.550 M HI(aq) must be added to a solution containing 0.700 mol of Pb(NO3)2 (aq) to completely precipitate the lead?
A) 197 B) 2.54 × 10-3 C) 0.394 D) 394 E) 0.197
Answer: D
19) Which one of the following is not true concerning 2.00 L of 0.100 M solution of Ca3(PO4)2?
A) This solution contains 0.800 mol of oxygen atoms.
B) 1.00 L of this solution is required to furnish 0.300 mol of Ca2+ ions.
C) This solution contains 6.67 × 10-2 mol of Ca2+.
D) This solution contains 0.200 mol of Ca3(PO4)2.
E) There are 6.02 × 1022 phosphorus atoms in 500.0 mL of this solution.
Answer: A
20) A 0.200 M K2SO4 solution is produced by __________.
A) dissolving 43.6 g of K2SO4 in water and diluting to a total volume of 250.0 mL B) diluting 20.0 mL of 5.00 M K2SO4 solution to 500.0 mL
C) dissolving 20.2 g of K2SO4 in water and diluting to 250.0 mL, then diluting 25.0 mL of this solution to a total volume of 500.0 mL
D) dilution of 250.0 mL of 1.00 M K2SO4 to 1.00 L E) dilution of 1.00 mL of 250 M K2SO3 to 1.00 L Answer: B
21) With which of the following will the ammonium ion form an insoluble salt?
A) carbonate
B) sulfate and carbonate C) sulfate
D) chloride
E) none of the above Answer: E
22) Mixing 10.00 mL of an aqueous solution with 10.00 mL of water represents a __________.
A) tenfold dilution B) crystallization C) titration D) neutralization
E) twofold dilution Answer: E
23) What are the respective concentrations (M) of Fe3+ and I- afforded by dissolving 0.200 mol FeI3 in water and diluting to 725 mL?
A) 0.828 and 0.276 B) 0.145 and 0.435 C) 0.276 and 0.828 D) 0.145 and 0.0483
E) 0.276 and 0.276 Answer: C
24) The balanced molecular equation for complete neutralization of H2SO4 by KOH in aqueous solution is __________.
A) 2H+ (aq) + 2OH- (aq) 2H2O (l)
B) H2SO4 (aq) + 2KOH (aq) 2H2O (l) + K2SO4 (aq) C) H2SO4 (aq) + 2OH- (aq) 2H2O (l) + SO42- (aq) D) H2SO4 (aq) + 2KOH (aq) 2H2O (l) + K2SO4 (s)
E) 2H+ (aq) + 2KOH (aq) 2H2O (l) + 2K+ (aq) Answer: B
25) The nucleus of an atom does not contain __________.
A) protons
B) subatomic particles C) protons or neutrons D) electrons
E) neutrons Answer: D
26) The nucleus of an atom contains __________.
A) protons and neutrons B) protons and electrons C) protons
D) electrons
E) protons, neutrons, and electrons Answer: A
27) Predict the charge of the most stable ion of potassium.
A) 1+ B) 3+ C) 2+ D) 2- E) 1-
Answer: A
28) The element X has two naturally occurring isotopes. The masses (amu) and % abundances of the isotopes are given in the table below. The average atomic mass of the element is __________ amu.
Isotope Abundance (%) Mass (amu)
31X 35.16 31.16
34X 64.84 34.30
A) 32.73 B) 30.20 C) 35.22 D) 34.02 E) 33.20
Answer: E
29) Elements in Group 7A are known as the __________.
A) alkaline earth metals B) alkali metals
C) chalcogens D) noble gases
E) halogens Answer: E
30) The name of the ionic compound NH4CN is __________.
A) ammonium hydrogen cyanate B) nitrogen hydrogen cyanate C) ammonium carbonitride D) ammonium cyanide
E) cyanonitride Answer: D
31) The charge on the copper ion in the salt CuO is __________.
A) -1 B) +2 C) +1 D) +3 E) -2
32) A certain mass of carbon reacts with 23.3 g of oxygen to form carbon monoxide. __________ grams of oxygen would react with that same mass of carbon to form carbon dioxide, according to the law of multiple
proportions?
A) 46.6 B) 25.6 C) 23.3 D) 11.7 E) 233
Answer: A
33) Elements in Group 6A are known as the __________.
A) alkaline earth metals B) alkali metals
C) halogens D) noble gases
E) chalcogens Answer: E
34) The mass number of an atom of 128Xe is __________.
A) 120 B) 128 C) 182 D) 74 E) 54
Answer: B
35) When the following equation is balanced, the coefficients are __________.
NH3 (g) + O2 (g) NO2 (g) + H2O (g)
A) 4, 7, 4, 6 B) 4, 3, 4, 3 C) 2, 3, 2, 3 D) 1, 3, 1, 2 E) 1, 1, 1, 1 Answer: A
36) The molecular weight of acetic acid ( HC2H3O2 ), the acid in vinegar, is __________ amu (rounded to one decimal place).
A) 59.0 B) 29.0 C) 32.0 D) 60.1 E) 8.0
Answer: D
37) How many grams of sodium carbonate contain 1.773 × 1017 carbon atoms?
A) 1.517 × 10-5 B) 3.121 × 10-5 C) 6.066 × 10-5 D) 9.100 × 10-5 E) 1.011 × 10-5 Answer: B
38) A compound that is composed of only carbon and hydrogen contains 80.0% C and 20.0% H by mass. What is the empirical formula of the compound?
A) C20H60 B) CH4 C) CH3 D) C2H6 E) C7H20
Answer: C
39) How many atoms of nitrogen are in 10 g of NH4NO3?
A) 3.5 B) 2 C) 1.5 × 1023 D) 3.0 × 1023 E) 1.8
Answer: C
40) What is the empirical formula of a compound that contains 49.4% K, 20.3% S, and 30.3% O by mass?
A) K2SO4 B) KSO4 C) K2SO3 D) KSO3 E) KSO2
Answer: C
41) How many molecules of CH4 are in 48.2 g of this compound?
A) 1.81 × 1024 B) 3.00 C) 5.00 × 1024 D) 4.00 E) 2.90 × 1025
Answer: A
42) Solid aluminum and gaseous oxygen react in a combination reaction to produce aluminum oxide:
4Al (s) + 3O2 (g) 2Al2O3 (s)
In a particular experiment, the reaction of 2.5 g of Al with 2.5 g of O2 produced 3.5 g of Al2O3. The % yield of the reaction is __________.
A) 37 B) 66 C) 47 D) 74 E) 26
Answer: D
43) Calculate the percentage by mass of nitrogen in Pb(NO3)2.
A) 8.5 B) 10.4 C) 5.2 D) 12.6 E) 4.2
Answer: A
44) The compound responsible for the characteristic smell of garlic is allicin, C6H10OS2. The mass of 1.00 mol of allicin, rounded to the nearest integer, is __________ g.
A) 61 B) 34 C) 86 D) 19 E) 162
Answer: E
45) There are __________ hydrogen atoms in 25 molecules of C4H4S2.
A) 100 B) 6.0 × 1025 C) 3.8 × 1024 D) 25 E) 1.5 × 1025
Answer: A
46) Silver nitrate and aluminum chloride react with each other by exchanging anions:
3AgNO3 (aq)+ AlCl3 (aq) Al(NO3)3 (aq) + 3AgCl (s)
What mass in grams of AgCl is produced when 4.22 g of AgNO3 react with 7.73 g of AlCl3?
A) 11.9 B) 17.6 C) 4.22 D) 3.56 E) 24.9
Answer: D
47) Pentacarbonyliron (Fe(CO)5) reacts with phosphorous trifluoride (PF3) and hydrogen, releasing carbon monoxide:
Fe(CO)5 + PF3 + H2 Fe(CO)2(PF3)2(H)2 + CO (not balanced)
The reaction of 5.0 mol of Fe(CO)5, 8.0 mol of PF3 and 6.0 mol of H2 will release __________ mol of CO.
A) 6.0 B) 5.0 C) 12 D) 15 E) 24
Answer: C
48) 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) 2, 3, and 4 B) 2 and 3 C) 1, 2, and 3 D) 4 only E) 1, 2, 3, and 4 Answer: D
49) The formula of nitrobenzene is C6H5NO2. The molecular weight of this compound is __________ amu.
A) 43.03 B) 3.06 C) 123.11 D) 109.10 E) 107.11
Answer: C
50) How many sulfur dioxide molecules are there in 0.180 mol of sulfur dioxide?
A) 6.02 × 1024 B) 6.02 × 1023 C) 1.08 × 1024 D) 1.80 × 1023 E) 1.08 × 1023 Answer: E
