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V–1

SECTION V: STOICHIOMETRY

INDEX: V001 LEVEL: (U) ANSWER: (B)KEYWORDS: formulas and equations, ALTERNATIVE FORMAT: (SA)

Omit responses.

When an electric discharge is passed through boron trichloride a new compound is formed. What is its simplest formula if on analysis it is shown to contain 0.0878 g of chlorine and 0.0131 g of boron?

Atomic Molar MassesB 10.8 g·mol–1

Cl 35.5 g·mol–1

(A) BCl (B) BCl2 (C) BCl3 (D) B2Cl3

INDEX: V002 LEVEL: (U) ANSWER: (A)KEYWORDS: formulas and equationsALTERNATIVE FORMAT: (SA)

Omit responses.

What is the empirical formula for the substance with this analysis:

Elemental AnalysisNa 54.0%B 8.50%O 37.5%


Na 23.0 g·mol–1

O 16.0 g·mol–1

(A) Na3BO3 (C) Na2B2O3

(B) Na4BO4 (D) NaB2O2


Omit responses.

A compound is found to consist of 34.9% sodium, 16.4% boron and 48.6% oxygen. Its simplest formula is


Na 23.0 g·mol–1

O 16.0 g·mol–1

(A) NaBO2 (D) Na3BO3

(B) NaBO3 (E) Na3BO4

(C) Na2B4O7


Omit responses.

When Pb(NO3)2 is heated in air, it decomposes to a lead oxide. If 2.00 g Pb(NO3)2 produce 1.35 g of the oxide, what is the formula of the oxide?

Atomic Molar MassesN 14. g·mol–1

O 16. g·mol–1

(SA) = short answer; (FR) = free response; (TF) = true/false (U) = understanding; (A) = analysis; (G) = generalization

V–2 Stoichiometry

Pb 207. g·mol–1

(A) PbO (B) PbO2 (C) Pb2O3 (D) Pb3O4

INDEX: V005 LEVEL: (U) ANSWER: (C)KEYWORDS: formulas and equationsALTERNATIVE FORMAT: (SA)

Omit responses.

If 2.68 g of hydrated sodium sulfate, Na2SO4.xH2O, on heating produces 1.26 g H2O, what is the empirical formula of this compound?

Molar MassesNa2SO4 142. g·mol–1

H2O 18.0 g·mol–1

(A) Na2SO4·3H2O (C) Na2SO4·7H2O

(B) Na2SO4·5H2O (D) Na2SO4·10H2O


A compound of sodium, sulfur, and oxygen contains 29.1% Na, 40.6% S, ad 30.3% 0. What is the correct empirical formula?

Atomic Molar MassesNa 23.0 g·mol–1

S 32.1 g·mol–1

O 16.0 g·mol–1

A compound of sodium, sulfur, and oxygen contains 29.08% Na, 40.56% S, and 30.36% 0. Which formula is correct?


S 32.1 g·mol–1

O 16.0 g·mol–1

(A) Na2SO3 (D) Na2S2O8

(B) Na2SO4 (E) Na2S4O6

(C) Na2S2O3

INDEX: V007 LEVEL: (A) ANSWER: (D)KEYWORDS: formulas and equations, organic chemistryALTERNATIVE FORMAT: (SA)

Omit responses.

A hydrocarbon undergoes complete combustion to give 0.44 g of CO2 and 0.27 g of H2O. What is the simplest (empirical) formula of the hydrocarbon?

Molar MassesCO2 44.0 g·mol–1

H2O 18.0 g·mol–1

(A) C44H27 (B) CH4 (C) C2H3 (D) CH3

INDEX: V008 LEVEL: (A) ANSWER: (B)KEYWORDS: formulas and equations, organic chemistryALTERNATIVE FORMAT: (SA)

A hydrocarbon (CxHy) was burned completely in air yielding 0.18 g of water and 0.44 g of carbon dioxide. What formula is consistent with this data?

A hydrocarbon (CxHy) was burned completely in air yielding 0.18 g of water and 0.44 g of carbon dioxide. Which formula could give such data?

Molar MassesCO2 44.0 g·mol–1

H2O 18.0 g·mol–1


Stoichiometry V–3

(A) C2H2 (B) C2H4 (C) C2H6 (D) C6H6

INDEX: V009 LEVEL: (U) ANSWER: (D)KEYWORDS: formulas and equations, organic chemistryALTERNATIVE FORMAT: (SA)

Omit responses.

A gaseous compound contained 90% carbon and 10% hydrogen by mass. What is the simplest formula for the gas?

Atomic Molar MassesC 12.0 g·mol–1

H 1.0 g·mol–1

(A) CH4 (B) C2H2 (C) C2H6 (D) C3H4

(E) C9H2O

INDEX: V010 LEVEL: (A) ANSWER: (B)KEYWORDS: formulas and equations, organic chemistry, gasesALTERNATIVE FORMAT: (SA)

Omit responses.

A gaseous compound of carbon and hydrogen contains 90% C and 10% H by mass. If 45 L of the gas has a mass of approximately 80 g at standard conditions, what is the molecular formula of the gas?


H 1.0 g·mol–1

(A) C6H8 (B) C3H4 (C) C7H14 (D) C3H8

INDEX: V011 LEVEL: (U) ANSWER: (A)KEYWORDS: formulas and equations, organic chemistryALTERNATIVE FORMAT: (SA)

Omit responses.

A compound containing only carbon and hydrogen has this composition: C = 80% and H = 20%. What is the simplest formula of the compound?


H 1.0 g·mol–1

(A) CH3 (B) CH4 (C) C2H6 (D) C3H8

(E) C4H

INDEX: V012 LEVEL: (U) ANSWER: (A)KEYWORDS: formulas and equations, organic chemistryALTERNATIVE FORMAT: (SA)

Omit responses.

The empirical (simplest) formula of a compound containing 54.53% carbon, 9.15% hydrogen, and 36.32% oxygen is


H 1.0 g·mol–1

O 16.0 g·mol–1

(A) C2H4O (D) C4H8O2

(B) C4H9O2 (E) CHO


V–4 Stoichiometry

(C) C5H9O

INDEX: V013 LEVEL: (U) ANSWER: (C)KEYWORDS: formulas and equations, organic chemistryALTERNATIVE FORMAT: (SA)

Omit responses.

The simplest (empirical) formula of a compound is C2H2O. At STP, 11.2 L has a mass of 63 g. What is the correct molecular formula?


H 1.0 g·mol–1

O 16.0 g·mol–1

(A) C4H4O2 (C) C6H6O3

(B) C3H1OO5 (D) C4H14O4

INDEX: V014 LEVEL: (A) ANSWER: (C)KEYWORDS: formulas and equations, organic chemistryALTERNATIVE FORMAT: (SA)

Omit responses.

The simplest formula of a substance is found to be CH2O, and its approximate molar mass is found by experiment to be 93 g·mol–1. What is its exact molar mass?


H 1.0 g·mol–1

O 16.0 g·mol–1

(A) 30.0 g·mol–1 (D) 92.0 g·mol–1

(B) 87.0 g·mol–1 (E) 93.0 g·mol–1

(C) 90.0 g·mol–1

INDEX: V015 LEVEL: (U) ANSWER: (D)KEYWORDS: formulas and equations, acids and basesALTERNATIVE FORMAT: (SA)

Omit responses.

A compound of hydrogen, chlorine and oxygen contains 1.18% H and 42.0% Cl. What is the simplest formula of this compound?

Atomic Molar MassesH 1.0 g·mol–1

O 16.0 g·mol–1

Cl 35.5 g·mol–1

(A) HCl (B) HClO (C) HClO2 (D) HClO3

(E) HClO4

INDEX: V016 LEVEL: (U) ANSWER: (C)KEYWORDS: formulas and equations, environmental and consumer chemistryALTERNATIVE FORMAT: (SA)

Omit responses.

A compound contains 30.5% nitrogen and 69.5% oxygen by mass and has a molar mass greater than 50 g·mol–1. What is its molecular formula?

Atomic Molar Masses


Stoichiometry V–5

N 14.0 g·mol–1

O 16.0 g·mol–1

(A) NO (B) NO2 (C) N2O4 (D) N2O3

(E) N2O5

INDEX: V017 LEVEL: (U) ANSWER: (A)KEYWORDS: formulas and equations, environmental and consumer chemistryALTERNATIVE FORMAT: (SA)

Omit responses.

A nitrogen oxide contains 46.67% nitrogen and 53.33% oxygen by mass. What is the simplest formula of this compound?

Atomic Molar MassesN 14.0 g·mol–1

O 16.0 g·mol–1

(A) NO (B) N2O (C) NO2 (D) N2O5

INDEX: V018 LEVEL: (U) ANSWER: (D)KEYWORDS: formulas and equationsALTERNATIVE FORMAT: (SA)

Omit responses.

An oxide of nitrogen contains 25.9% nitrogen and 74.1% oxygen by mass. What is the empirical formula of this compound?


O 16.0 g·mol–1

(A) NO (B) NO2 (C) N2O3 (D) N2O5


Omit responses.

A compound was analyzed and found to contain 36.9% nitrogen and 63.1% oxygen. What is the simplest formula for this compound?


O 16.0 g·mol–1

(A) N2O (B) NO (C) N2O3 (D) NO2

(E) N2O5


Omit responses.

An oxysulfide of phosphorus was found to contain 39.2% phosphorus, 40.4% oxygen and 20.3% sulfur. Its simplest formula is

Atomic Molar MassesP 31.0 g·mol–1

S 32.1 g·mol–1

O 16.0 g·mol–1

(A) P2O4S (C) P4O6S2


V–6 Stoichiometry

(B) POS (D) P2O3·SO2

INDEX: V021 LEVEL: (A) ANSWER: (B)KEYWORDS: formulas and equations, laboratoryALTERNATIVE FORMAT: (SA)

Omit responses.


Stoichiometry V–7

. ..

0.0 0.2 0.4 0.6 0.8 1.0mole fraction of A

1.0

2.0

3.0(SA) = short answer; (FR) = free response; (TF) = true/false (U) = understanding; (A) = analysis; (G) = generalization

V–8 Stoichiometry

INDEX: V022 LEVEL: (A) ANSWER: (D)KEYWORDS: formulas and equationsALTERNATIVE FORMAT: (SA)

Omit responses.

The atomic molar mass of a hypothetical element X is 100 u. It is found that the 50.0 g of X combines with 32.0 g of oxygen. What is the simplest formula for the oxide of X?

Atomic Molar MassO 16.0 g·mol–1

(A) X2O (B) XO2 (C) X2O3 (D) XO4

INDEX: V023 LEVEL: (U) ANSWER: (C)KEYWORDS: formulas and equations, environmental and consumer chemistry, organic chemistryALTERNATIVE FORMAT: (SA)

Omit responses.

An amino acid has a molar mass of 776.9 g·mol–1 and contains 65.34% iodine by mass. What is the number of iodine atoms per molecule of amino acid?

(A) one (B) three (C) four (D) five

INDEX: V024 LEVEL: (A) ANSWER: (B)KEYWORDS: formulas and equations, laboratory, metals & nonmetalsALTERNATIVE FORMAT: (SA)

Omit responses.

A 6.80 g coin was dissolved in nitric acid and 6.21 g of AgCl was precipitated by the addition of excess sodium chloride,

Ag+(aq) + Cl–(aq) AgCl(s)

Calculate the percentage silver in the coin.

Atomic Molar MassesAg 108. g·mol–1

Cl 135.5 g·mol–1

(A) 24.7% (B) 68.7% (C) 75.3% (D) 91.3%

INDEX: V025 LEVEL: (U) ANSWER: (C)KEYWORDS: formulas and equations, coordination chemistry, gasesALTERNATIVE FORMAT: (SA)

Omit responses.

If a 17.0 g sample of impure nickel metal reacts under standard conditions with 25.0 L of CO to form 6.25 L of Ni(CO)4 gas, what is the percentage of Ni in the metal sample?

Ni(s) + 4CO(g) Ni(CO)4(g)

Molar MassesNi 58.7 g·mol–1

Ni(CO)4 171. g·mol–1

(A) 24.1% (B) 25.0% (C) 96.4% (D) 100%

INDEX: V026 LEVEL: (U) ANSWER: (B)KEYWORDS: formulas and equations, metals & nonmetals, laboratoryALTERNATIVE FORMAT: (SA)

Omit responses.

A 2.000 g sample of a Ni-Tl-Zn alloy is dissolved in nitric acid and 1.750 g of thallium(I) iodide, TlI, is precipitated by the addition of hydriodic acid. Calculate the percentage of thallium in the alloy.

Molar Masses


Stoichiometry V–9

Ni 58.71 g·mol–1

Tl 204.4 g·mol–1

Zn 65.37 g·mol–1

TlI 331.3 g·mol–1

(A) 39.03% (B) 53.98% (C) 62.22% (D) 87.50%

INDEX: V027 LEVEL: (U) ANSWER: (B)KEYWORDS: formulas and equations, metals & nonmetalsALTERNATIVE FORMAT: (SA)

Omit responses.

A piece of silver foil having a mass of 0.5840 g had become tarnished because of formation of Ag2S, with a mass increase of 0.0010 g. What percentage of the original silver has been converted to Ag2S?

Atomic Molar MassesS 32. g·mol–1

Ag 108. g·mol–1

(A) 0.6% (B) 1.2% (C) 1.8% (D) 2.4%


Omit responses.

What is the percentage of nitrogen by mass in (NH4)3PO4?


N 14.0 g·mol–1

O 16.0 g·mol–1

P 31.0 g·mol–1

(A) 14/62 100% (C) 14/l13 100%

(B) 21/80 100% (D) 42/149 100%

INDEX: V029 LEVEL: (A) ANSWER: (B)KEYWORDS: formulas and equations, laboratory, metals & nonmetalsALTERNATIVE FORMAT: (SA)

Omit responses.

A 2.00 g mixture of NaCl and NaNO3 dissolved in water required 90 mL of 0.10 M AgNO3 to precipitate all the chloride. What is the mass percentage of NaCl in the original sample?


Ag 107.9 g·mol–1

Cl 35.5 g·mol–1

N 14.0 g·mol–1

O 16.0 g·mol–1

(A) 10 (B) 26 (C) 58 (D) 90

INDEX: V030 LEVEL: (A) ANSWER: (A)KEYWORDS: formulas and equationsALTERNATIVE FORMAT: (SA)

Omit responses.

The formula of a hypothetical compound of tellurium is M2Te. Its composition is 80.0% Te, 20.0% M. The approximate atomic molar mass of element M is

Atomic Molar Mass


V–10 Stoichiometry

Te 127 g·mol–1

(A) 16 g·mol–1 (D) 79 g·mol–1

(B) 32 g·mol–1 (E) 159 g·mol–1

(C) 51 g·mol–1

INDEX: V031 LEVEL: (U) ANSWER: (D)KEYWORDS: formulas and equations, organic chemistryALTERNATIVE FORMAT: (TF)

The formula for methane is CH4. This means that in methane . Use each response in a separate question.


H 1.0 g·mol–1

The formula for methane is CH4. This means that, in methane,


H 1.0 g·mol–1

(A) for every 100 atoms of hydrogen there are 400 atoms of carbon.

(B) for every atom of carbon there are four grams of hydrogen.

(C) for every gram of hydrogen there are twelve grams of carbon.

(D) the compound is 25% hydrogen by mass.

(E) the compound is 80% hydrogen by mass.


Omit responses.

The percent by mass of oxygen in Ca(NO3)2 is

Atomic Molar MassesCa 40.1 g·mol–1

N 14.0 g·mol–1

O 16.0 g·mol–1

(A) 100 (D) 100

(B) 100 (E) 100

(C) 100


What is the mass fraction of oxygen in K2SO4·Al2(SO4)3·24H2O?

The mass fraction of oxygen in K2SO4·Al2(SO4)3·24H2O can be represented as

Molar MassesK2SO4 174.3 g·mol–1

Al2(SO4)3 342.1 g·mol–1

H2O 18.0 g·mol–1

(A) (C)


Stoichiometry V–11

(B) (D)


Omit responses.

How many moles of Fe are needed to produce10.0 mol of H2?

4H2O(g) + 3Fe(s) Fe3O4(s) + 4H2(g)

(A)7.50 mol (C) 15.0 mol

(B) 13.3 mol (D) 30.0 mol

INDEX: V035 LEVEL: (U) ANSWER: (D)KEYWORDS: formulas and equations, environmental and consumer chemistryALTERNATIVE FORMAT: (SA)

Omit responses.

Assuming complete oxidation in the reaction

C(s) + O2(g) CO2(g)

what mass of CO2 will 15 g of carbon produce?

Molar MassesC 12. g·mol–1

O2 32. g·mol–1

CO2 44. g·mol–1

(A) 11 g (B) 22 g (C) 44 g (D) 55 g


Omit responses.

How many grams of aluminum chloride can one obtain from 6.00 mol of barium chloride?

Al2(SO4)3 + 3BaCl2 3BaSO4 + 2AlCl3

Atomic Molar MassesAl 27.0 g·mol–1

Cl 35.5 g·mol–1

(A) 1250 g (B) 801 g (C) 534 g (D) 134 g


Omit responses.

If 0.50 mol of Na3PO4 is mixed with 0.30 mol of BaCl2, the maximum number of moles of barium phosphate which can be formed is

(A) 0.10 (B) 0.15 (C) 0.30 (D) 0.50

INDEX: V038 LEVEL: (A) ANSWER: (B)KEYWORDS: formulas and equations, environmental and consumer chemistryALTERNATIVE FORMAT: (SA)

Omit responses.

How many moles of sulfur dioxide, SO2, can be produced from 160 g of sulfur and 320 g of oxygen?

Atomic Molar MassesS 32. g·mol–1

O 16. g·mol–1

(A) 2.5 mol (B) 5.0 mol (C) 7.5 mol (D) 10.0 mol




Omit responses.

A reaction between Na2O and P4O10 forms Na3PO4. How many grams of Na3PO4 will be produced from the reaction of 0.200 mol of Na2O with excess P4O10?

Molar MassesNa3PO4 164. g·mol–1

Na2O 62. g·mol–1

P4O10 284. g·mol–1

(A) 21.9 g (B) 32.8 g (C) 43.8 g (D) 131 g

INDEX: V040 LEVEL: (A) ANSWER: (C)KEYWORDS: formulas and equations, laboratoryALTERNATIVE FORMAT: (SA)

Omit responses.

What mass of KClO3 will produce 48.0 g of oxygen if the decomposition is complete?

Molar MassesKClO3 122.5 g·mol–1

O2 32.0 g·mol–1

(A) 61.3 g (B) 74.5 g (C) 122.5 g (D) 245.0 g

INDEX: V041 LEVEL: (A) ANSWER: (C)KEYWORDS: formulas and equationsALTERNATIVE FORMAT: (SA)

Omit responses.

The density of a liquid sulfur compound is 1.14 g·mL–1. This compound contains 23.7% sulfur. How many milliliters of the compound must be burned to obtain 6.40 g of SO2?

Molar MassSO2 64.1 g·mol–1

(A) 1.52 (B) 4.22 (C) 11.9 (D) 23.7


Omit responses.

What mass of iron(III) sulfide is produced from the reaction of 11.6 g of iron(III) nitrate with excess sodium sulfide?

2Fe(NO3)3(aq) + 3Na2S(aq) Fe2S3(s) + 6NaNO3(aq)

Molar MassesFe2S3 208 g·mol–1

Fe(NO3)3 242 g·mol–1

(A) 4.99 g (B) 6.75 g (C) 9.97 g (D) 11.6 g

INDEX: V043 LEVEL: (U) ANSWER: (C)KEYWORDS: formulas and equations, organic chemistryALTERNATIVE FORMAT: (SA)

Omit responses.

What mass of oxygen is needed for complete combustion of 88.6 mL of C6H6 to carbon dioxide and water?

2 C6H6(l) + 15O2(g) 12CO2(g) + 6H2O(l)



Molar MassesC6H6 208 g·mol–1

O2 32 g·mol–1

CO2 44 g·mol–1

H2O 18 g·mol–1

DensityC6H6 0.88 g·mL–1

(A) 7.5 g (B) 19 g (C) 240 g (D) 310 g


Omit responses.

A sample of Fe2O3 was found to contain 10.2 g of iron. How many moles of iron are there in the sample?

Atomic Molar MassesFe 55.85 g·mol–1

O 16.00 g·mol–1

(A) 0.180 (B) 0.360 (C) 2.00 (D) 3.60

INDEX: V045 LEVEL: (U) ANSWER: (C)KEYWORDS: formulas and equationsALTERNATIVE FORMAT: (TF)

Ammonia gas is released when an ammonium salt is heated with calcium hydroxide. A sample of will give a greater mass of ammonia than will a sample of when heated with excess calcium hydroxide. Use pairs of responses in separate questions.

Ammonia gas is released when an ammonium salt is heated with calcium hydroxide. Which sample will give the greatest mass of ammonia when heated with excess calcium hydroxide?

Molar MassesNH4NO3 80. g·mol–1

(NH4)2SO4 132. g·mol–1

NH4Cl 53.5 g·mol–1

(A) 120 g NH4NO3 (C) 120 g NH4Cl

(B) 66 g (NH4)2SO4 (D) 1 mol of (NH4)2SO4

INDEX: V046 LEVEL: (U) ANSWER: (A)KEYWORDS: introductory conceptsALTERNATIVE FORMAT: (TF)

The number of atoms in 9.0 g of aluminum is the same as the number of atoms in . Use each response in a separate question.


Mg 24.3 g·mol–1

The number of atoms in 9.0 g of aluminum is the same as the number of atoms in


Mg 24.3 g·mol–1

(A) 8.1 g of magnesium. (D) 18.0 g of magnesium.

(B) 9.0 g of magnesium. (E) 24.3 g of magnesium.

(C) 12.15 g of magnesium.

INDEX: V047 LEVEL: (U) ANSWER: (A)KEYWORDS: introductory concepts

A new element, X, is discovered. Analysis of four of its compounds showed the following number of grams of X in



ALTERNATIVE FORMAT: (SA)Omit responses.

one mole of each compound:

Compound: I II III IVGrams of X: 160 240 160 320

What is the most probable atomic molar mass of X?

(A) 80 g·mol–1 (D) 320 g·mol–1

(B) 160 g·mol–1 (E) 640 g·mol–1

(C) 240 g·mol–1

INDEX: V048 LEVEL: (A) ANSWER: (C)KEYWORDS: formulas and equationsALTERNATIVE FORMAT: (TF)

would produce 18.0 g of H2O. Use each response in a separate question.


H 1.0 g·mol–1

Na 23.0 g·mol–1

O 16.0 g·mol–1

S 32.0 g·mol–1

Which reaction, carried out with the kind and amounts of reactants given, would produce 18.0 g of H2O?


H 1.0 g·mol–1

Na 23.0 g·mol–1

O 16.0 g·mol–1

S 32.0 g·mol–1

(A) complete combustion of 16.0 g CH4

(B) complete combustion of 12.0 g H2

(C) neutralization of 40.0 g NaOH with H2SO4

(D) complete dehydration of one mole of Na2CO3·10H2O


Omit responses.

A 5.00 g sample of a metal reacts with 4.00 g of oxygen gas, O2, to form an oxide with a formula MO. What is the atomic molar mass of the metal?

Atomic Molar MassesO 16.0 g·mol–1

(A) 10.0 (B) 16.0 (C) 20.0 (D) 40.0

(E) 80.0

INDEX: V050 LEVEL: (A) ANSWER: (A)KEYWORDS: introductory conceptsALTERNATIVE FORMAT: (SA)

Omit responses.

Three volatile compounds containing element Q were analyzed and this data obtained:

ApproximateMolar Mass Percent Q in

Compound (g·mol–1) Compound1 60 402 90 403 96 50



The approximate atomic molar mass of Q, from these data, is

(A) 12. (B) 24. (C) 36. (D) 48.

(E) 72.

INDEX: V051 LEVEL: (A) ANSWER: (B)KEYWORDS: formulas and equations, metals & nonmetalsALTERNATIVE FORMAT: (SA)

Omit responses.

Hydrochloric acid reacts with CaCO3 according to equation (1). What mass of NaOH would be required to react according to equation (2) with the CO2 liberated from

20 g of CaCO3?

CaCO3(s) + 2HCl(aq) CaCl2(aq) + H2O(l) + CO2(g) (1)CO2(g) + NaOH(aq) Na2CO3(aq) + H2O(l) (2)


Ca 40.1 g·mol–1

H 1.0 g·mol–1

Na 23.0 g·mol–1

O 16.0 g·mol–1

(A) 8.0 g (B) 16 g (C) 20 g (D) 40 g

(E) 44 g

INDEX: V052 LEVEL: (U) ANSWER: (D)KEYWORDS: formulas and equations, oxidation and reductionALTERNATIVE FORMAT: (SA)

Omit responses.

0.3000 mol of aluminum metal is combined with chlorine to form aluminum chloride, AlCl3. How many grams of chlorine are combined with the metal?


Cl 35.5 g·mol–1

(A) 0.900 g (B) 8.10 g (C) 10.7 g (D) 32.0 g

(E) 40.1 g

INDEX: V053 LEVEL: (U) ANSWER: (D)KEYWORDS: introductory conceptsALTERNATIVE FORMAT: (TF)

The expression “one mole of copper(II) sulfide” refers to . Use each response in a separate question.

To what mass does the expression “one mole of copper(II) sulfide” refer?

(A) the mass of copper(II) sulfide needed to occupy one liter

(B) the mass of solid copper(II) sulfide needed to occupy 22.4 L at STP.

(C) the mass of copper combined with sulfur in one molecule.



(D) the mass of copper(II) sulfide in grams equal to one formula molar mass

(E) the mass in grams of one molecule of copper(II) sulfide

INDEX: V054 LEVEL: (U) ANSWER: (E)KEYWORDS: introductory conceptsALTERNATIVE FORMAT: (SA)

A single molecule of a certain compound weighs 3.4 10–22 g. What is its molar mass?

A single molecule of a certain compound weighs 3.4 10–22 g. Which figure comes nearest to the mass of a mole as ordinarily expressed?

(A) 25 g·mol–1 (D) 150 g·mol–1

(B) 50 g·mol–1 (E) 200 g·mol–1

(C) 100 g·mol–1

INDEX: V055 LEVEL: (A) ANSWER: (D)KEYWORDS: laboratoryALTERNATIVE FORMAT: (SA)

Omit responses.

Given the experimental data for three compounds of the element X, it can be deduced that a reasonable provisional atomic molar mass of element X in g·mol–1 is

Approximate PercentMolar Mass of X

Compound 1 60 g·mol–1 40Compound 2 90 g·mol–1 40Compound 3 48 g·mol–1 50

(A) 72 (B) 36 (C) 24 (D) 12

(E) 6

INDEX: V056 LEVEL: (A) ANSWER: (B)KEYWORDS: formulas and equationsALTERNATIVE FORMAT: (SA)

Omit responses.

The atomic mass of an element is 32.06 u and its atomic number is 16. What number of grams of this element will combine with 1.008 g of hydrogen?

Atomic Molar MassH 1.008 g·mol–1

(A) 8.02 (B) 16.03 (C) 32.06 (D) 64.12

INDEX: V057 LEVEL: (U) ANSWER: (E)KEYWORDS: solutions and colloids,ALTERNATIVE FORMAT: (SA)

Omit responses.

A 40–mL portion of a 0.1 M MgSO4 solution contains how many grams of MgSO4?

Atomic Molar MassesMg 24.3 g·mol–1

O 16.0 g·mol–1

S 32.1 g·mol–1

(A) 120 g (B) 24 g (C) 0.96 g (D) 0.6 g

(E) 0.48 g



INDEX: V058 LEVEL: (U) ANSWER: (D)KEYWORDS: solutions and colloids, laboratoryALTERNATIVE FORMAT: (SA)

Omit responses.

What mass of MgCl2 is required to prepare 2.00 L of 0.550 M solution?

Molar MassMgCl2 95.2 g·mol–1

(A) 1.10 g (B) 28.9 g (C) 86.5 g (D) 105 g

INDEX: V059 LEVEL: (U) ANSWER: (C)KEYWORDS: solutions and colloids, organic chemistryALTERNATIVE FORMAT: (SA)

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What is the concentration of CH3OH in 0.20 Lof aqueous solution which contains 55 g CH3OH?

Molar MassCH3OH 32.0 g·mol–1

(A) 1.7 M (B) 0.34 M (C) 8.6 M (D) 2.9 M


Omit responses.

What mass of Na2SO4·10H2O is required to prepare 500 mL of 0.20 M Na2SO4 solution?

Molar MassNa2SO4·10H2O 322.2 g·mol–1

(A) 5.0 g (B) 10 g (C) 28 g (D) 32 g

INDEX: V061 LEVEL: (U) ANSWER: (B)KEYWORDS: solutions and colloidsALTERNATIVE FORMAT: (SA)

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What is the molarity of a solution containing 11.7 g of NaCl in 400 mL of solution?

Molar MassNaCl 58.5 g·mol–1

(A) 0.0290 M (C) 2.92 M

(B) 0.500 M (D) 5.00 M

INDEX: V062 LEVEL: (U) ANSWER: (B)KEYWORDS: solutions and colloids, laboratoryALTERNATIVE FORMAT: (SA)

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How many grams of sodium sulfate are needed to make 2.00 L of a 0.250 M solution?

Molar MassNa2SO4 142 g·mol–1

(A) 30.5 (B) 71.0 (C) 142 (D) 284

INDEX: V063 LEVEL: (U) ANSWER: (A)KEYWORDS: acids and bases, solutions and colloids, laboratoryALTERNATIVE FORMAT: (SA)

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To what volume in liters must 105 mL of hydrochloric acid, containing 47.5 g of HCl, be diluted to make a 1.05 M solution?




Cl 35.5 g·mol–1

(A) 1.24 L (B) 1.30 L (C) 2.00 L (D) 3.40 L

INDEX: V064 LEVEL: (U) ANSWER: (C)KEYWORDS: acids and bases, solutions and colloidsALTERNATIVE FORMAT: (SA)

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An aqueous solution containing 49 g of sulfuric acid per liter has a concentration of

Molar MassH2SO4 98.1 g·mol–1

(A)1.0 M (C) 0.50 M

(B) 4.9% by mass (D) 4.9 M

INDEX: V065 LEVEL: (A) ANSWER: (C)KEYWORDS: acids and bases, solutions and colloids, laboratoryALTERNATIVE FORMAT: (SA)

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A 1.20 L sample is drawn from a bottle labeled “86.0% by weight H2SO4, density 1.787 g·mL–1”. What is the molarity of the sample?


(A) 8.78 M (B) 10.5 M (C) 5.7 M (D) 18.2 M

INDEX: V066 LEVEL: (U) ANSWER: (A)KEYWORDS: solutions and colloidsALTERNATIVE FORMAT: (SA)

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What is the molarity of a solution 15.0 mL of which contains 89.3 mg KBr?

Molar MassKBr 119 g·mol–1

(A) 0.0500 M (C) 0.170 M

(B) 0.0900 M (D) 19.0 M

INDEX: V067 LEVEL: (A) ANSWER: (C)KEYWORDS: solutions and colloids, acids and basesALTERNATIVE FORMAT: (SA)

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A solution containing 70.0% HF by mass has a density of 1.25 g·mL–1. Its molarity, with respect to HF, is

Molar MassHF 20.0 g·mol–1

(A) 28.0 M (B) 35.5 M (C) 43.8 M (D) 84.3 M

INDEX: V068 LEVEL: (U) ANSWER: (B)KEYWORDS: solutions and colloids, laboratoryALTERNATIVE FORMAT: (SA)

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How many grams of CuSO4·5H2O are required for the preparation of 200 mL of a 0.1 M solution of CuSO4?

Atomic Molar MassesCu 63.5 g·mol–1

H 1.0 g·mol–1

O 16.0 g·mol–1



S 32.0 g·mol–1

(A) 3.2 g (B) 5 g (C) 16 g (D) 25 g

(E) 50 g


Omit responses.

How many grams of CuSO4·5H2O are required to make 3.00 L of a 0.150 M solution?

Molar MassCuSO4·5H2O 249.6 g·mol–1

(A) 37.4 (B) 71.8 (C) 95.0 (D) 112

INDEX: V070 LEVEL: (U) ANSWER: (B)KEYWORDS: solutions and colloids, acids and basesALTERNATIVE FORMAT: (SA)

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How many grams of H2SO4 are there in 135 mL of 0.250 M H2SO4?


(A) 1.65 (B) 3.31 (C) 6.62 (D) 13.2

INDEX: V071 LEVEL: (U) ANSWER: (B)KEYWORDS: solutions and colloids, acids and basesALTERNATIVE FORMAT: (SA)

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A sulfuric acid solution contains 80.0% by mass of H2SO4 and has a density of 1.73 g·mL–1. What is its molarity?

(A) 1.0 (B) 14.1 (C) 18.0 (D) 28.2

(E) 36.0

INDEX: V072 LEVEL: (U) ANSWER: (A)KEYWORDS: acids and bases, solutions and colloidsALTERNATIVE FORMAT: (SA)

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Two liters of a solution contain 147 g of sulfuric acid. What is the molarity of the solution?


O 16.0 g·mol–1

S 32.1 g·mol–1

(A) 0.75 N (B) 1.5 N (C) 2.25 N (D) 2.94 N

(E) 3.0 N

INDEX: V073 LEVEL: (U) ANSWER: (C)KEYWORDS: acids and bases, solutions and colloidsALTERNATIVE FORMAT: (SA)

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A 75.0% (by mass) solution of H3PO4 has a density of 1.60 g·mL–1. What is the molarity of the solution?

Molar MassH3PO4 98.0 g·mol–1

(A) 7.4 (B) 9.8 (C) 12.2 (D) 16.3



(E) 36.6

INDEX: V074 LEVEL: (U) ANSWER: (B)KEYWORDS: oxidation and reduction, laboratoryALTERNATIVE FORMAT: (SA)

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What volume of 0.100 M SO32–(aq) is needed to titrate

24.0 mL of 0.200 M Fe3+(aq)?

2Fe3+(aq) + SO32–(aq) + H2O(l)

2Fe2+(aq) + SO42–(aq) + 2H+(aq)

(A) 48.0 mL (B) 24.0 mL (C) 12.0 mL (D) 6.00 mL

INDEX: V075 LEVEL: (U) ANSWER: (B)KEYWORDS: acids and bases, laboratoryALTERNATIVE FORMAT: (SA)

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If 10 mL of 6.0 M NaOH neutralizes 30 mL of hydrochloric acid, what is the molarity of the acid?

(A) 1.0 M (B) 2.0 M (C) 3.0 M (D) 0.20 M

INDEX: V076 LEVEL: (U) ANSWER: (D)KEYWORDS: acids and bases, laboratoryALTERNATIVE FORMAT: (SA)

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10.0 mL of a solution of acetic acid, HC2H3O2, requires 25.0 mL of 0.400 M sodium hydroxide to neutralize it. How many moles of acetic acid are present in the sample?

(A) 2.00 (B) 1.00 (C) 0.100 (D) 0.0100

INDEX: V077 LEVEL: (U) ANSWER: (D)KEYWORDS: acids and basesALTERNATIVE FORMAT: (SA)

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In the reaction

3Ca(OH)2(s) + 2H3PO4(aq) Ca3(PO4)2(s) + 6H2O(l)

how many grams of Ca(OH)2 are required to neutralize 10 L of 0.60 M H3PO4 solution?

Molar MassesCa(OH)2 74. g·mol–1

H3PO4 94. g·mol–1

(A) 300 g (B) 330 g (C) 390 g (D) 670 g

INDEX: V078 LEVEL: (U) ANSWER: (C)KEYWORDS: acids and basesALTERNATIVE FORMAT: (SA)

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How many grams of CaO will react with 30.0 L of 1.00 l0–3 M Na3PO4 solution, assuming complete reaction?

2PO43–(aq) + 3Ca2+(aq) Ca3(PO4)2(s)

Molar MassCaO 56.1 g·mol–1

(A) 1.2 (B) 1.68 (C) 2.52 (D) 7.57

INDEX: V079 LEVEL: (U) ANSWER: (C) What volume of 0.131 M BaCl2 is required to react



KEYWORDS: metals & nonmetals, laboratoryALTERNATIVE FORMAT: (SA)

Omit responses.

completely with 42.0 mL of 0.453 M Na2SO4?

Ba2+(aq) + SO42–(aq) BaSO4(s)

(A) 12.1 mL (B) 72.6 mL (C) 145 mL (D) 290 mL

INDEX: V080 LEVEL: (U) ANSWER: (C)KEYWORDS: acids and bases, laboratoryALTERNATIVE FORMAT: (SA)

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What volume of 0.060 M H2SO4 will neutralize 50.00 mL of 0.24 M NaOH?

(A) 12.5 mL (B) 25 mL (C) 100 mL (D) 200 mL

INDEX: V081 LEVEL: (U) ANSWER: (C)KEYWORDS: acids and bases, laboratoryALTERNATIVE FORMAT: (SA)

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If 26.32 mL of 0.100 M H2SO4 is exactly neutralized by 34.56 mL of NaOH solution, what is the molar concentration of the original base solution?

(A) 0.0762 M (C) 0.152 M

(B) 0.131 M (D) 0.262 M

INDEX: V082 LEVEL: (A) ANSWER: (A)KEYWORDS: acids and bases, laboratoryALTERNATIVE FORMAT: (SA)

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A 25.0-mL sample of HNO3 was titrated with standard 0.100 M NaOH solution. The end–point was reached when 20.0 mL of the NaOH solution was added. How many grams of HNO3 did the sample contain?

Molar MassHNO3 63.0 g·mol–1

(A) 0.126 g (B) 0.155 g (C) 0.197 g (D) 0.252 g

(E) 0.312 g

INDEX: V083 LEVEL: (U) ANSWER: (B)KEYWORDS: acids and bases, laboratoryALTERNATIVE FORMAT: (SA)

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One hundred milliliters of a solution of oxalic acid, (COOH)2, is neutralized with 50.0 mL of 0.750 M KOH solution. What is the molarity of the oxalic acid solution?

(A) 0.099 M (D) 0.375 M

(B) 0.188 M (E) 0.750 M

(C) 0.333 M

INDEX: V084 LEVEL: (U) ANSWER: (B)KEYWORDS: oxidation and reduction, laboratoryALTERNATIVE FORMAT: (SA)

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In acidic solution the dichromate ion, Cr2O72– will oxidize

Fe2+ to Fe3+ with the formation of Cr3+. How many milliliters of 0.100 M K2Cr2O7 is required to oxidize 60.0 mL of 0.250 M FeSO4?

(A) 7.00 mL (B) 25.0 mL (C) 42.0 mL (D) 58.4 mL

(E) 175 mL



INDEX: V085 LEVEL: (A) ANSWER: (E)KEYWORDS: acids and bases, laboratoryALTERNATIVE FORMAT: (SA)

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When 50 mL of 0.10 M HCl is mixed with 50 mL of 0.30 M NaOH, what is the approximate pH of the resulting solution?

(A) 1 (B) 7 (C) 9 (D) 11

(E) 13

INDEX: V086 LEVEL: (A) ANSWER: (D)KEYWORDS: acids and bases, formulas and equationsALTERNATIVE FORMAT: (FR)

What is the difference, if any, in the amount of 0.1 M sodium hydroxide solution required to titrate one liter of 0.1 M acetic acid or one liter of 0.1 M HCl to the equivalence point? Explain your answer.

Given one liter of 0.1 M acetic acid and one liter of 0. l M hydrochloric acid:

(A) Both solutions have the same pH.

(B) Both solutions contain the same number of H3O+ ions.

(C) Both solutions contain the same number of grams of acid.

(D) Both solutions would require the same amount of 0.1 M NaOH solution for titration to the equivalence point.

(E) If both were titrated with the same amount of 0.1 M NaOH solution, the resulting solutions would have the same pH.

INDEX: V087 LEVEL: (U) ANSWER: (B)KEYWORDS: acids and bases, laboratory, formulas and equationsALTERNATIVE FORMAT: (SA)

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One liter of a 0.100 M solution of HNO3 would be neutralized by what volume of 0.400 M Ba(OH)2?

(A) 0.25 L (B) 0.50 L (C) l.0 L (D) 2.0 L

(E) 4.0 L

INDEX: V088 LEVEL: (A) ANSWER: (D)KEYWORDS: acids and bases, laboratory, formulas and equationsALTERNATIVE FORMAT: (SA)

A sample of 25.0 mL of vinegar (acetic acid) is titrated with standard sodium hydroxide solution, which is 0.500 M. If 30.0 mL of the NaOH solution are required for exact neutralization (phenolphthalein as indicator), the concentration of the vinegar is

A sample of 25.0 mL of vinegar (acetic acid) is titrated with standard sodium hydroxide solution, which is 0.500 M. If 30.0 mL of the NaOH solution are required for exact neutralization (phenolphthalein as indicator), the vinegar is

(A) 0.060 M (B) 0.425 M (C) 0.450 M (D) 0.600 M

(E) 6.00 M

INDEX: V089 LEVEL: (U) ANSWER: (A)KEYWORDS: acids and bases, laboratory, formulas and equationsALTERNATIVE FORMAT: (SA)

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30 mL of 0.02 M HCl is to be neutralized with 0.02 M Ba(OH)2. What volume of Ba(OH)2 solution must be used?

(A) 15 mL (B) 30 mL (C) 60 mL (D) 120 mL

INDEX: V090 LEVEL: (U) ANSWER: (D) What volume of 3 M NaOH would be required to



KEYWORDS: acids and bases, laboratory, formulas and equationsALTERNATIVE FORMAT: (SA)

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neutralize 10 mL of 6 M H2SO4?

(A) 20 mL (B) 10 mL (C) 120 mL (D) 40 mL

(E) 2.5 mL

INDEX: V091 LEVEL: (U) ANSWER: (D)KEYWORDS: acids and bases, laboratory, formulas and equationsALTERNATIVE FORMAT: (SA)

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What volume, in milliliters, of 0.05 M Ba(OH)2 is required to neutralize 30 mL of 0.2 M HCl?

(A) 3 (B) 6 (C) 30 (D) 60

(E) 120

INDEX: V092 LEVEL: (A) ANSWER: (E)KEYWORDS: acids and bases, laboratoryALTERNATIVE FORMAT: (SA)

When 50 mL of 0.1 M HCl is mixed with 50 mL of 0.2 M NaOH, what is the resulting hydronium ion concentration?

When 50 mL of 0.1 M HCl is mixed with 50 mL of 0.2 M NaOH, the resulting hydronium ion concentration will be

(A) 0.05 M. (D) l 10–7 M.

(B) 0.1 M. (E) none of these

(C) 0.2 M.

INDEX: V093 LEVEL: (U) ANSWER: (B)KEYWORDS: gases, industrial chemistryALTERNATIVE FORMAT: (SA)

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What mass of CaCO3 will produce 8.0 L of CO2 (measured at STP) in this reaction.

CaCO3(s) CaO(s) + CO2(g) ?

Molar MassCaCO3 100. g·mol–1

(A)g (C) g

(B) 100 g (D) 100 g

INDEX: V094 LEVEL: (U) ANSWER: (C)KEYWORDS: gases, organic chemistry, environmental and consumer chemistry, oxidation and reductionALTERNATIVE FORMAT: (SA)

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How many liters of CO2 gas at STP can be obtained by completely burning one mole of C3H8?

C3H8(g) + 5O2(g) 3CO2(g) + 4H2O(g)

(A) 11.2 (B) 44.8 (C) 67.2 (D) 112

INDEX: V095 LEVEL: (U) ANSWER: (B)KEYWORDS: gases, oxidation and reductionALTERNATIVE FORMAT: (SA)

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What volume of pure N2O at STP could be prepared by the controlled decomposition of 8.00 g of ammonium nitrate?

NH4NO3(s) N2O(g) + 2H2O(l)


O 16.0 g·mol–1



H 1.01 g·mol–1

(A) 1.12 L (B) 2.24 L (C) 3.36 L (D) 4.48 L

INDEX: V096 LEVEL: (U) ANSWER: (B)KEYWORDS: gases, organic chemistry, oxidation and reductionALTERNATIVE FORMAT: (SA)

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Benzene, C6H6, can be burned in oxygen according to the equation:

2C6H6(l) + 15O2(g) 12CO2(g) + 6H2O(g)

If 5.0 L of oxygen measured at STP were required to burn a given amount of benzene, the STP volume of CO2 formed would be

(A) 22.4 L

(B) 5.0 L

(C) 2.78 g benzene

(D) 5.0 L

INDEX: V097 LEVEL: (U) ANSWER: (B)KEYWORDS: gases, industrial chemistry, oxidation and reductionALTERNATIVE FORMAT: (SA)

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How many moles of H2O can be produced when 8.0 g of O2 are used in the reaction, assuming an ample amount of NH3?

4NH3(g) + 5O2(g) 4NO(g) + 6H2O(l)

Molar MassO2 32.0 g·mol–1

(A) 0.28 (B) 0.30 (C) 0.40 (D) 0.60

INDEX: V098 LEVEL: (U) ANSWER: (D)KEYWORDS: gases, industrial chemistryALTERNATIVE FORMAT: (SA)

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How many liters of hydrogen gas at STP are required to prepare 45.0 g of ammonia?

N2(g) + 3H2(g) 2NH3(g)

Molar MassesN2 28.0 g·mol–1

H2 2.0 g·mol–1

(A) 39.5 (B) 30.0 (C) 59.3 (D) 88.9

INDEX: V099 LEVEL: (U) ANSWER: (B)KEYWORDS: gases, oxidation and reductionALTERNATIVE FORMAT: (SA)

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How many liters of hydrogen at STP can be produced by the reaction of 9.00 g of Al with excess dilute H2SO4?

Atomic Molar MassAl 27.0 g·mol–1

2Al(s) + 3H2SO4(aq) Al2(SO4)3(aq) + 3H2(g)



(A) 5.61 L (B) 11.2 L (C) 33.6 L (D) 67.2 L

INDEX: V100 LEVEL: (U) ANSWER: (D)KEYWORDS: gases, organic chemistry, oxidation and reduction, formulas and equationsALTERNATIVE FORMAT: (SA)

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Gaseous 2-propanol burns in air according to the equation

C3H7OH(g) + O2(g) CO2(g) + H2O(g) (not balanced)

What volume of air (20% oxygen) is required to burn 3 L of 2-propanol?

(A) 9.0 L (B) 13.5 L (C) 22.4 L (D) 67.5 L

INDEX: V101 LEVEL: (U) ANSWER: (A)KEYWORDS: gases, oxidation and reductionALTERNATIVE FORMAT: (SA)

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If 11.2 L of NO2(g) at STP reacted with water, how many moles of HNO2 would form?

2NO2(g) + H2O(l) HNO2(aq) + HNO3(aq)

(A) 0.25 mol (C) 1.0 mol

(B) 0.50 mol (D) 1.5 mol

INDEX: V102 LEVEL: (A) ANSWER: (D)KEYWORDS: gases, organic chemistry, oxidation and reduction, formulas and equationsALTERNATIVE FORMAT: (SA)

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What mass of oxygen is needed to oxidize completely 88 g of propane, C3H8, to give only the products CO2 and H2O?

Molar MassesC3H8 44.1 g·mol–1

O2 32.0 g·mol–1

(A) 96 g (B) 160 g (C) 192 g (D) 320 g

(E) 640 g

INDEX: V103 LEVEL: (U) ANSWER: (D)KEYWORDS: gases, metals & nonmetalsALTERNATIVE FORMAT: (SA)

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What volume of ammonia gas, NH3, measured at STP, will be produced by the decomposition of two moles of ammonium carbonate?

(NH4)2CO3(s) 2NH3(g) + CO2(g) + H2O(g)

(A) 22.4 L (B) 33.6 L (C) 44.8 L (D) 89.6 L

(E) 112 L

INDEX: V104 LEVEL: (U) ANSWER: (A)KEYWORDS: gases, industrial chemistryALTERNATIVE FORMAT: (SA)

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In the reaction

N2(g) + 3H2(g) 2NH3(g)

what volume of nitrogen will combine with 12 L of hydrogen, both measured at STP?

(A) 4 L (B) 8 L (C) 12 L (D) 22.4 L



(E) 28 L

INDEX: V105 LEVEL: (U) ANSWER: (C)KEYWORDS: gases, metals & nonmetalsALTERNATIVE FORMAT: (SA)

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Given the equation

Sb2S3(s) + 6H+(aq) 2Sb3+(aq) + 3H2S(g)

What volume of H2S, measured at STP, can be formed from 0.5 mol of Sb2S3?

(A) 8.4 L (B) 16.8 L (C) 33.6 L (D) 44.8 L

(E) 67.2 L

INDEX: V106 LEVEL: (A) ANSWER: (A)KEYWORDS: gases, laboratoryALTERNATIVE FORMAT: (TF)

Experimental evidence for the assertion that the formula of hydrogen sulfide gas is H2S is that . Use each response in a separate question.

The best experimental evidence for the assertion that the formula of hydrogen sulfide gas is H2S is that

(A) at STP the mass of 22.4 L of hydrogen sulfide gas is 34 g, of which 32 g is sulfur.

(B) sulfur and hydrogen atoms combine in a ratio of two to one.

(C) free hydrogen gas consists of H2 molecules, but sulfuris solid.

(D) when hydrogen sulfide is burned in air or oxygen, H2O and SO2 are formed.

(E) the sulfur atom has six electrons in its outer level, and obtains the two electrons needed for a stable arrangement by combining with two hydrogen atoms.

INDEX: V107 LEVEL: (A) ANSWER: (B)KEYWORDS: gases, organic chemistry, industrial chemistryALTERNATIVE FORMAT: (SA)

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If 6.41 g of CaC2 react with an excess of water, according to the equation

CaC2(s) + 2H2O(l) C2H2(g) + Ca(OH)2(aq)

how many liters of C2H2, measured dry at STP, are obtained?


C 12.0 g·mol–1

H 1.0 g·mol–1

O 16.0 g·mol–1

(A) 0.100 (B) 2.24 (C) 2.60 (D) 11.2

(E) 22.4



INDEX: V108 LEVEL: (A) ANSWER: (A)KEYWORDS: gases, acids and basesALTERNATIVE FORMAT: (SA)

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Given the equation:

SO2(g) + CaO(s) CaSO3(s)

what volume of SO2 at standard conditions is required to prepare 30 g of CaSO3?


S 32.1 g·mol–1

O 16.0 g·mol–1

(A) 5.6 L (B) 11.2 L (C) 16.8 L (D) 22.4 L

(E) 33.6 L

INDEX: V109 LEVEL: (A) ANSWER: (A)KEYWORDS: gases, industrial chemistry, organic chemistry, oxidation and reductionALTERNATIVE FORMAT: (SA)

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The equation for the complete combustion of ethanol is

C2H5OH(l) + 3O2(g) 2CO2(g) + 3H2O(g)

The volume of oxygen required for each liter of carbon dioxide produced, assuming all volumes are measured at 20 °C and 1 atm pressure, is

(A) 1.5 L

(B) 1.5 22.4 L

(C) 3 L

(D) 22.4 L

(E) L

INDEX: V110 LEVEL: (A) ANSWER: (E)KEYWORDS: gases, organic chemistry, industrial chemistry, oxidation and reductionALTERNATIVE FORMAT: (SA)

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Acetylene burns according to the equation

2C2H2(g) + 5O2(g) 4CO2(g) + 2H2O(g)

The amount of CO2 produced by burning 2 L of C2H2 gas, assuming that all volumes are under standard conditions, would he:

(A) 4 22.4 L (D) 4 mol

(B) 4 44 g (E) 4 L

(C) 4 g

INDEX: V111 LEVEL: (A) ANSWER: (D)KEYWORDS: oxidation and reduction, gasesALTERNATIVE FORMAT: (FR)

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Assume the reaction of magnesium with these three acids takes place as shown and goes to completion.

(1) Mg + 2HCl MgCl2 + H2



(2) Mg + H2SO4 MgSO4 + H2

(3) 3Mg + 2H3PO4 Mg3(PO4)2 + 3H2

If an equal mass of magnesium is dissolved in each acid, how will the yields of gas compare under the same conditions?

(A) Reactions (1) and (2) yield equal volumes of hydrogen, and reaction (3) yields a larger volume.

(B) Reactions (1) ad (2) yield equal volumes of hydrogen, and reaction (3) yields a smaller volume, since phosphoric acid is a weak acid.

(C) Reaction (1) yields the smallest volume of hydrogen; reaction (2) yields twice as great a volume as reaction (1); and reaction (3) yields three times as great a volume as reaction (1).

(D) All three reactions yield equal volumes of hydrogen.

(E) Reaction (2) yields the same volume of hydrogen as reaction (1), and reaction (3) yields three times as great a volume as reaction (1).

INDEX: V112 LEVEL: (U) ANSWER: (A)KEYWORDS: formulas and equations, gases, acids and bases, laboratoryALTERNATIVE FORMAT: (SA)

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When 0.2 mol of NaHCO3 reacts with excess sulfuric acid, the volume of dry CO2 produced at 30 °C and at a pressure of 740 mmHg is

(A) 4.48 (D) 8.80

(B) 4.48 (E) 4.48

(C) 2.24

INDEX: V113 LEVEL: (U) ANSWER: (C)KEYWORDS: gases, organic chemistry, oxidation and reduction, environmental and consumer chemistryALTERNATIVE FORMAT: (SA)

If 1 L of C3H8 and 5 L of O2 react according to the equation

C3H8 + 5O2 3CO2 + 4H2O

and and assuming that all products are in the gaseous state, then what volume will the products will occupy (under the same conditions)?

If 1 L of C3H8 and 5 L of O2 react completely according to the equation

C3H8(g) + 5O2(g) 3CO2(g) + 4H2O(g)

and assuming that all products are in the gaseous state, then the products will occupy (under the same conditions)

(A) 1 L (B) 6 L (C) 7 L (D) 8 L

INDEX: V114 LEVEL: (A) ANSWER: (C)KEYWORDS: gases, organic chemistry, oxidation and reduction, environmental and consumer chemistry, formulas and equations

How many liters of air (containing 20% oxygen by volume) are needed to burn completely 4 L of propane, if both gases are measured at standard conditions?



ALTERNATIVE FORMAT: (SA)Omit responses.

(A) 5 (B) 20 (C) 100 (D) 22.4 5

INDEX: V115 LEVEL: (U) ANSWER: (A)KEYWORDS: gases, oxidation and reduction, formulas and equations, laboratoryALTERNATIVE FORMAT: (SA)

What mass, in grams, of H2O2 are necessary to obtain one liter of oxygen at standard conditions?


O 16.0 g·mol–1

Which expression would give the mass, in grams, of H2O2 necessary to obtain one liter of oxygen at standard conditions?


O 16.0 g·mol–1

(A) (D)

(B) (E)

(C)

INDEX: V116 LEVEL: (U) ANSWER: (B)KEYWORDS: gases, industrial chemistry, oxidation and reduction, environmental and consumer chemistry, organic chemistryALTERNATIVE FORMAT: (SA)

Omit responses.

Ethane gas burns according to the equation

2C2H6(g) + 7O2(g) 4CO2(g) + 6H2O(g)

How many liters of CO2, measured at STP, are formed for each mole of C2H6 burned?

(A) 22.4 (B) 44.8 (C) 88.0 (D) 89.6

(E) 176

INDEX: V117 LEVEL: (A) ANSWER: (B)KEYWORDS: gases, industrial chemistry, oxidation and reduction, environmental and consumer chemistry, organic chemistryALTERNATIVE FORMAT: (SA)

Omit responses.

What is the maximum mass of CO2 which can be produced by the reaction between one mole of CH4 and one mole of O2? Assume the reaction to be

CH4(g) + 2O2(g) CO2(g) + 2H2O(g)

Molar MassesCH4 16. g·mol–1

O2 32. g·mol–1

CO2 44. g·mol–1

H2O 18. g·mol–1

(A) 11 g (B) 22 g (C) 33 g (D) 44 g

INDEX: V118 LEVEL: (A) ANSWER: (A)KEYWORDS: gases, oxidation and reductionALTERNATIVE FORMAT: ( )

Assume that the reaction between hydrogen and oxygen goes to completion. Which statement is true if 10.0 g of hydrogen is mixed with 64.0 g of oxygen and ignited?

Atomic Molar Masses



H 1.01 g·mol–1

O 16.0 g·mol–1

(A) The limiting reagent is oxygen.

(B) 74 g of water will form.

(C) 3 mol of hydrogen will be left over after the reaction.

(D) 68 g of water will form.

INDEX: V119 LEVEL: (A) ANSWER: (C)KEYWORDS: metals & nonmetals, oxidation and reduction, formulas and equationsALTERNATIVE FORMAT: (SA)

Omit responses.

How many moles of Al2O3 can be produced from 27 g of aluminum and 16 g of oxygen?


O 16.0 g·mol–1

(A) 0.67 (B) 0.50 (C) 0.33 (D) 0.17

INDEX: V120 LEVEL: (A) ANSWER: (B)KEYWORDS: gases, oxidation and reductionALTERNATIVE FORMAT: (SA)

Omit responses.

Beginning with 84.0 g CaH2 and 18.0 g H2O, how many liters of H2 at STP can be produced in this reaction?

CaH2(s) + 2H2O(l) 2H2(g) + Ca(OH)2(s)

Molar MassesCaH2 42.0 g·mol–1

H2O 18.0 g·mol–1

(A) 11.2 L (B) 22.4 L (C) 44.8 L (D) 89.6 L

INDEX: V121 LEVEL: (A) ANSWER: (A)KEYWORDS: acids and basesALTERNATIVE FORMAT: (SA)

Omit responses.

If 7.30 g of HCl and 4.00 g of NH3 are mixed, how many grams of NH4Cl can be formed?

HCl(g) + NH3(g) NH4Cl(s)

Molar MassesHCl 36.5 g·mol–1

NH3 17.0 g·mol–1

(A) 10.7 (B) 11.3 (C) 12.6 (D) 13.3

INDEX: V122 LEVEL: (A) ANSWER: (A)KEYWORDS: oxidation and reductionALTERNATIVE FORMAT: (SA)

Omit responses.

How many moles of NH3 can be formed when 0.50 mol of NCl3 is allowed to react with 0.40 mol of H2?

2NCl3 + 3H2 2NH3 + 3Cl2

(A) 0.27 mol (C) 0.60 mol



(B) 0.50 mol (D) 0.90 mol

INDEX: V123 LEVEL: (A) ANSWER: (C)KEYWORDS: acids and basesALTERNATIVE FORMAT: (SA)

Omit responses.

What mass of NH3 remains after a mixture of 73.0 g of NH3 and 73.0 g of HCl undergo reaction?

NH3(g) + HCl(g) NH4Cl(s)

Molar MassesNH3 17.0 g·mol–1

HCl 36.5 g·mol–1

(A) 0.00 g (B) 19.5 g (C) 39.0 g (D) 73.0 g

INDEX: V124 LEVEL: (A) ANSWER: (B)KEYWORDS: oxidation and reductionALTERNATIVE FORMAT: (SA)

Omit responses.

How much of each reactant remains after 54 g of aluminum and 32 g of oxygen undergo the reaction

4Al(s) + 3O2(g) 2Al2O3(s)

Atomic Molar MassesAl 27 g·mol–1

O 16 g·mol–1

(A) no Al, no O2 (C) no Al, 8.0 g O2

(B) 18 g Al, no O2 (D) 6.0 g Al, no O2

INDEX: V125 LEVEL: (A) ANSWER: (A)KEYWORDS: oxidation and reduction, formulas and equationsALTERNATIVE FORMAT: (SA)

Omit responses.

Magnesium hydride contains 92.4% Mg. If 2.30 g of hydrogen and 30.0 g of magnesium are brought to reaction conditions, how many grams of will be formed?

(A) 30.2 (B) 27.9 (C) 15.0 (D) 14.0

INDEX: V126 LEVEL: (A) ANSWER: (E)KEYWORDS: formulas and equations, solutions and colloidsALTERNATIVE FORMAT: (SA)

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If 0.50 mol of CaCl2 is mixed with 0.20 mol of Na3PO4, the maximum number of moles of Ca3(PO4)2 that can be formed is

(A) 0.67 (B) 0.50 (C) 0.20 (D) 0.17

(E) 0.10

INDEX: V127 LEVEL: (A) ANSWER: (C)KEYWORDS: ALTERNATIVE FORMAT: (SA)

Omit responses.

A hypothetical compound, AB, consists of 76% by mass A and 24.0% by mass B. If 19.0 g of A is allowed to react with 24.0 g of B, what mass of AB is formed?

(A) 6.0 g (B) 18.0 g (C) 25.0 g (D) 27.0 g

(E) 43.0 g



INDEX: V128 LEVEL: (A) ANSWER: (D)KEYWORDS: gases, oxidation and reduction, organic chemistry, environmental and consumer chemistry, industrial chemistryALTERNATIVE FORMAT: (SA)

Omit responses.

The reaction

2C2H6(g) + 7O2(g) 4CO2(g) + 6H2O(g)

is carried out at an elevated temperature at which the reaction goes essentially to completion. All gas volumes are measured at the same temperature and pressure. If the reaction mixture was originally composed of 3.0 L of C2H6 and 3.5 L of O2, the volume of the gaseous mixture remaining after the reaction would be

(A) 5.0 L (B) 6.0 L (C) 6.5 L (D) 7.0 L

(E) 10.0 L

INDEX: V129 LEVEL: (A) ANSWER: (A)KEYWORDS: oxidation and reduction, environmental and consumer chemistryALTERNATIVE FORMAT: (SA)

Omit responses.

When 24.3 g of magnesium is burned in 32.0 g of oxygen, which reactant, if any, will be in excess?

Atomic Molar MassesMg 24.3 g·mol–1

O 16.0 g·mol–1

(A) oxygen (C) both reactants

(B) magnesium (D) neither reactant

INDEX: V130 LEVEL: (A) ANSWER: (A)KEYWORDS: industrial chemistry, acids and basesALTERNATIVE FORMAT: (SA)

Omit responses.

What is the maximum mass of (NH4)2SO4 that could be formed from 17 pounds of NH3 and 100 pounds of solution containing 49 per cent H2SO4 by mass if they react according to the equation

2NH3(g) + H2SO4(aq) (NH4)2SO4(aq)


N 14.0 g·mol–1

O 16.0 g·mol–1

S 32.0 g·mol–1

(A) 66 lb (B) 67 lb (C) 67 g (D) 117 lb

(E) 117 g

INDEX: V131 LEVEL: (A) ANSWER: (D)KEYWORDS: formulas and equations, organic chemistryALTERNATIVE FORMAT: (SA)

Omit responses.

A 6.16 g sample of CCl4 reacted with excess oxidizing agent to form 3.64 g of COCl2 as the only carbon-containing compound. What was the percentage yield of the process?

Molar MassesCCl4 154. g·mol–1

COCl2 99. g·mol–1



(A) 59% (B) 78% (C) 84% (D) 92%

INDEX: V132 LEVEL: (A) ANSWER: (D)KEYWORDS: organic chemistry, industrial chemistryALTERNATIVE FORMAT: (SA)

Omit responses.

When 30.0 g of CH4 reacts completely with excess chlorine yielding 52.0 g of HCl, what is the percentage yield?

CH4(g) + Cl2(g) CH3Cl(g) + HCl(g)

Molar MassesCH4 16.0 g·mol–1

HCl 36.5 g·mol–1

(A) 24.0% (B) 25.2% (C) 42.3% (D) 76.0%

INDEX: V133 LEVEL: (A) ANSWER: (B)KEYWORDS: oxidation and reduction, gasesALTERNATIVE FORMAT: (SA)

Omit responses.

Given the equation in which the element molybdenum has been prepared by the reduction of molybdenum trioxide by hydrogen:

MoO3(s) + 3H2(g) Mo(s) + 3H2O(g)

When 24.0 g of molybdenum trioxide reacts with 11.2 L of hyrdogen measured at STP, the mass of molybdenum produced was 14.4 g. What is the percent of theoretical yield?

Atomic Molar MassesO 16.0 g·mol–1

Mo 96.0 g·mol–1

(A) 100.% (B) 90.0% (C) 60.7% (D) 50.6%


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