Deck 3: Mass Relationships in Chemical Reactions

Question 1

Sodium phosphate reacts with sulfuric acid to form sodium sulfate and phosphoric acid.What is the stoichiometric coefficient for sulfuric acid when the chemical equation is balanced using the lowest whole-number stoichiometric coefficients?

A)1
B)2
C)3
D)none of these

Answer 1

3

Question 2

What is the molar mass of aspartic acid,C₄O₄H₇N?

A)43 g/mol
B)70 g/mol
C)133 g/mol
D)197 g/mol

Answer 2

133 g/mol

Question 3

How many sulfate ions are there in 5.00 g of FeSO₄?

A)5.46 × 10^-26 iron (II)ions
B)1.98 × 10²² iron (II)ions
C)1.83 × 10²⁵ iron (II)ions
D)4.58 × 10²⁶ iron (II)ions

Answer 3

1.98 × 10²² iron (II)ions

Question 4

Which one of the following statements about balanced equations is false? In a balanced reaction

A)atoms must be balanced on both sides of the reaction arrow.
B)mass must be conserved.
C)molecules must be balanced on both sides of the reaction arrow.
D)net charge must be balanced on both sides of the reaction arrow.

Question 5

Given the chemical equation: N₂ + 3 H₂ → 2 NH₃.On a macroscopic level,what do the coefficients mean?

A)1 atom of nitrogen reacts with 3 atoms of hydrogen to give 2 atoms of ammonia.
B)1 mole of nitrogen reacts with 3 moles of hydrogen to give 2 moles of ammonia.
C)1 molecule of nitrogen reacts with 3 molecules of hydrogen to give 2 molecules of ammonia.
D)All of these are true.

Question 6

What is the sum of the coefficients when the following equation is balanced using the lowest whole-numbered coefficients? ________ B₂O₃(s)+ ________ HF(l)→ ________ BF₃(g)+ ________ H₂O(l)

A)8
B)11
C)15
D)none of these

Question 7

Chemical equations are balanced in order to obey the law of

A)definite proportions.
B)mass action.
C)mass conservation.
D)multiple proportions.

Question 8

How many moles are in 1.50 g of ethylamine,CH₃CH₂NH₂?

A)0.0222 mol
B)0.0332 mol
C)90.16 mol
D)45.08 mol

Question 9

Which contains Avogadro's number of formula units?

A)36.5 g of Cl
B)36.5 g of Cl₂
C)36.5 g of HCl
D)All of these

Question 10

What is the mass of a single ozone molecule,O₃?

A)2.656 × 10^-23 g
B)7.969 × 10^-22 g
C)16.0 g
D)48.0 g

Question 11

Which one of the following statements about balanced equations is true? A reaction is balanced by

A)changing the charge on an ion.
B)changing the formula of the molecule.
C)multiplying by suitable coefficients.
D)rearranging atoms in a molecule.

Question 12

Which conducts electricity?

A)a large collection of iron atoms
B)a single iron atom
C)both a large collection of iron atoms and a single iron atom
D)neither a large collection of iron atoms nor a single iron atom

Question 13

How many sodium atoms are in 3.00 g of sodium dichromate,Na₂Cr₂O₇?

A)0.023 oxygen atoms
B)2.82 × 10²⁰ oxygen atoms
C)1.97 × 10²¹ oxygen atoms
D)1.38 × 10²² oxygen atoms

Question 14

What is the molar mass of calcium permanganate?

A)159 g/mol
B)199 g/mol
C)216 g/mol
D)278 g/mol

Question 15

1.00 mole of O₂ contains the same number of oxygen atoms as

A)0.667 mole of O₃.
B)1.00 mole of CH₃CO₂H.
C)2.00 mole of CH₃CH₂OH.
D)All of the above

Question 16

What is the sum of the coefficients when the following equation is balanced using the lowest whole-numbered coefficients? ________ PH₃(g)+ ________ O₂(g)→ ________ P₄O₁₀(s)+ ________ H₂O(g)

A)10
B)12
C)19
D)22

Question 17

Given the chemical equation: N₂ + 3 H₂ → 2 NH₃.On a molecular level,what do the coefficients mean?

A)1 atom of nitrogen reacts with 3 atoms of hydrogen to give 2 atoms of ammonia.
B)28 g of nitrogen reacts with 6 grams of hydrogen to give 34 grams of ammonia.
C)1 mole of nitrogen reacts with 3 moles of hydrogen to give 2 moles of ammonia.
D)1 molecule of nitrogen reacts with 3 molecules of hydrogen to give 2 molecules of ammonia.

Question 18

What is the mass of 0.0500 mol of dichlorodifluoromethane,CF₂Cl₂?

A)4.14 × 10^-4 g
B)6.05 g
C)12.1 g
D)24.2 g

Question 19

What is the molar mass of iodine?

A)126.9 g/mol
B)253.8 g/mol
C)6.02 × 10²³ g/mol
D)1.20 × 10²⁴ g/mol

Question 20

What is the molar mass of Co(NO₃)₂?

A)90 g/mol
B)121 g/mol
C)152 g/mol
D)183 g/mol

Question 21

How many grams of calcium chloride are needed to produce 10.0 g of potassium chloride? CaCl₂(aq)+ K₂CO₃(aq)→ 2 KCl(aq)+ CaCO₃(aq)

A)0.134 g
B)7.44 g
C)9.28 g
D)18.56 g

Question 22

If the percent yield for the following reaction is 60.0%,and 45.0 g of NO₂ are consumed in the reaction,how many grams of nitric acid,HNO₃(aq),are produced?
3 NO₂(g)+ H₂O(l)→ 2 HNO₃(aq)+ NO(g)

A)24.6 g
B)41.1 g
C)54.8 g
D)69.3 g

Question 23

What is the identity of substance X if 0.380 mol of X weighs 17.5 g?

A)NO₂
B)NO₃
C)N₂O
D)N₂O₄

Question 24

What mass of sulfur hexafluoride,SF₆,has the same number of fluorine atoms as 50.0 g of oxygen difluoride,OF₂?

A)202.7 g
B)8.33 g
C)43.0 g
D)135.1 g

Question 25

Which of the following has the greatest mass?

A)6.02 × 10²³ molecules of Cl₂
B)35.45 g of Cl₂
C)0.500 mol of Cl₂
D)All of these have the same mass.

Question 26

What is the molar mass of aspirin if 5.19 × 10¹⁶ molecules of aspirin weigh 15.53 μg?

A)180 g/mol
B)80.6 g/mol
C)133.8 g/mol
D)200 g/mol

Question 27

When methane,CH₄,undergoes combustion with oxygen,the usual products are carbon dioxide and water.Carbon monoxide is formed when the limiting reactant is

A)carbon dioxide.
B)methane.
C)oxygen.
D)water.

Question 28

How many cations are in 0.500 g of MgBr₂?

A)1.37 × 10²¹ anions
B)1.64 × 10²¹ anions
C)2.22 × 10²⁶ anions
D)4.43 × 10²⁶ anions

Question 29

Balance the chemical equation given below,and determine the number of moles of iodine that reacts with 5.0 g of aluminum. ________ Al(s)+ ________ I₂(s)→ ________ Al₂I₆(s)

A)0.185 mol
B)0.278 mol
C)0.139 mol
D)0.834 mol

Question 30

3.0 moles of nitrogen is reacted with 11.0 moles of hydrogen to produce ammonia according to the chemical equation shown below.Which one of the following statements is false? N₂(g)+ 3 H₂(g)→ 2 NH₃(g)

A)2.0 moles of hydrogen are left over.
B)Hydrogen is the excess reactant.
C)Nitrogen is the limiting reactant.
D)12.0 moles of ammonia are produced.

Question 31

The density of ethanol,C₂H₅OH,is 0.789 g/mL.How many milliliters of ethanol are needed to produce 5.00 g of CO₂ according to the following chemical equation?
C₂H₅OH(l)+ 3 O₂(g)→ 2 CO₂(g)+ 3 H₂O(l)

A)2.06 mL
B)3.32 mL
C)6.60 mL
D)13.3 mL

Question 32

Which of the following has the smallest mass?

A)6.02 × 10²³ molecules of I₂
B)70.0 g of Cl₂
C)2.00 mol of F₂
D)0.040 kg of Br₂

Question 33

In the reaction between glucose and oxygen,10.0 g of glucose reacts and 7.50 L of carbon dioxide is formed.What is the percent yield if the density of CO₂ is 1.26 g/L?
C₆H₁₂O₆(s)+ 6 O₂(g)→ 6 CO₂(g)+ 6 H₂O(l)

A)26.1%
B)40.6%
C)43.1%
D)64.5%

Question 34

Balance the chemical equation given below,and determine the number of grams of Fe needed to produce 15.0 g of Fe₂O₃. ________ MgO(s)+ ________ Fe(s)→ ________ Fe₂O₃(s)+ ________ Mg(s)

A)11.36 g
B)3.78 g
C)5.245 g
D)10.49 g

Question 35

How many anions are in 10.0 g of sodium phosphate?

A)3.67 × 10²² cations
B)1.10 × 10²³ cations
C)9.87 × 10²⁴ cations
D)2.96 × 10²⁵ cations

Question 36

Which of the following has the greatest mass?

A)6.0 × 10²³ atoms of O
B)3.0 × 10²³ molecules of O₂
C)2.0 × 10²³ molecules of O₃
D)All have the same mass.

Question 37

5.0 g of nitrogen is reacted with 5.0 g of hydrogen to produce ammonia according to the chemical equation shown below.Which one of the following statements is false?
N₂(g)+ 3 H₂(g)→ 2 NH₃(g)

A)2.8 grams of hydrogen are left over.
B)Hydrogen is the excess reactant.
C)Nitrogen is the limiting reactant.
D)The theoretical yield of ammonia is 6.1 g.

Question 38

What mass of carbon monoxide,CO,contains the same number of molecules as 3.00 g of trichlorofluoromethane,CCl₃F?

A)3.00 g
B)0.612 g
C)1.63 g
D)9.33 g

Question 39

Tablets of ascorbic acid,or Vitamin C,C₆H₈O₆,are taken as a dietary supplement.If a typical tablet contains 500 mg,how many molecules of Vitamin C are in a tablet?

A)500 molecules
B)1.71 × 10²⁴ molecules
C)3.0 × 10²⁴ molecules
D)1.71 × 10²¹ molecules

Question 40

4.0 g of iron is reacted with 4.0 g of water according to the chemical equation shown below.Which one of the following statements is false? 3 Fe(s)+ 4 H₂O(l)→ Fe₃O₄(s)+ 4 H₂(g)

A)6.91 g of Fe₃O₄ are produced.
B)2.28 g of H₂O are left over.
C)Mass is conserved in this reaction.
D)Fe is the limiting reactant.

Question 41

The sugar fructose has an empirical formula of CH₂O.The mass spectrum shows a molecular ion peak at a mass of 179.9.What is the molecular formula of fructose?

A)CH₂O
B)C₂H₄O₄
C)C₆H₁₁O₆
D)C₆H₁₂O₆

Question 42

Consider two reactants,A and B.The molar mass of A is greater han the molar mass of B.You add equal masses of A and B together and let them react.Which of the following statements must be true?

A)Reactant A must be limiting.
B)Reactant B must be limiting.
C)Reactant A is the excess reactant.
D)None of the above choices must be true.

Question 43

Which statement about elemental analysis by combustion is not correct?

A)Carbon is determined from the amount of CO₂ formed.
B)Hydrogen is determined from the amount of H₂O formed.
C)Oxygen is determined from the amount of H₂O formed.
D)Only carbon and hydrogen can be determined directly from CO₂ and H₂O.

Question 44

How many grams of the excess reagent are left over when 6.00 g of CS₂ gas react with 10.0 g of Cl₂ gas in the following reaction? CS₂(g)+ 3 Cl₂(g)→ CCl₄(l)+ S₂Cl₂(l)

A)2.42 g
B)2.77 g
C)3.58 g
D)4.00 g

Question 45

What is the empirical formula for ethyl fluoride if the compound contains 49.97% carbon,10.51% hydrogen,and 39.52% fluorine by mass?

A)C₂H₅F
B)C₄H₁₀F₂
C)C₄H₁₀F₄
D)C₂₅F₂

Question 46

Which of the following statements about mass spectrometry is false?

A)Mass spectrometry can be used to determine the molecular weight of a compound.
B)The curvature of the path in a magnetic field is determined by the mass of the ion.
C)The paths of heavier ions are deflected more strongly than the paths of lighter ions.
D)The sample is changed into positively charged ions.

Question 47

Which one of the following contains 38.7% carbon by mass?

A)C₂H₂
B)CH₄
C)CH₃NH₂
D)CO₂

Question 48

In the combustion analysis of an unknown compound containing only carbon,hydrogen,and oxygen,the grams of oxygen are found from the grams of

A)CO₂ only.
B)H₂O only.
C)CO₂ and H₂O only.
D)CO_2,H₂O and unknown compound.

Question 49

A compound responsible for the odor of garlic has a molecular weight of 146 g/mol.A 0.650 g sample of the compound contains 0.321 g of carbon,0.044 g of hydrogen,and 0.285 g of sulfur.What is the molecular formula of the compound?

A)CH₅S
B)C₃H₅S
C)C₃H₁₅S₃
D)C₆H₁₀S₂

Question 50

When silver nitrate reacts with barium chloride,silver chloride and barium nitrate are formed.How many grams of silver chloride are formed when 8.0 g of silver nitrate reacts with 15.0 g of barium chloride?

A)6.752 g
B)9.40 g
C)11.9 g
D)18.8 g

Question 51

Which of the following statements is false concerning the formula of a compound?

A)The empirical formula is the simplest whole numbered ratio of atoms in a compound.
B)The molecular formula is the true ratio of atoms in a compound.
C)The molecular formula and empirical formula can be identical.
D)The number of atoms in a molecular formula is always greater than the number of atoms in an empirical formula.

Question 52

Combustion analysis of an unknown compound containing only carbon and hydrogen produced 2.845 g of CO₂ and 1.744 g of H₂O.What is the empirical formula of the compound?

A)CH₂
B)CH₃
C)C₄H₁₀
D)C₅H₂

Question 53

Each molecule of cortisone contains 21 atoms of carbon (plus other atoms).The mass percentage of carbon in cortisone is 69.98%.What is the molar mass of cortisone?

A)176.5 g/mol
B)252.2 g/mol
C)287.6 g/mol
D)360.4 g/mol

Question 54

Acetone has the formula C₃H₆O.Which ball and stick model shown above represents acetone? [gray spheres = C,black spheres = O,unshaded spheres = H]

A)model a)
B)model b)
C)model c)
D)model d)

Question 55

When iron(III)oxide reacts with hydrochloric acid,iron(III)chloride and water are formed.How many grams of iron(III)chloride are formed from 10.0 g of iron(III)oxide and 10.0 g of hydrochloric acid?

A)11.1 g
B)14.8 g
C)20.3 g
D)35.1 g

Question 56

Molecular mass can be determined by

A)combustion analysis.
B)mass spectrometry.
C)titration.
D)weighing with an analytical balance.

Question 57

Combustion analysis of 2.796 g of an unknown compound containing carbon,hydrogen,and oxygen produced 5.597 g of CO₂ and 2.268 g of H₂O.What is the empirical formula of the compound?

A)C₂H₅O
B)C₂H₅O₂
C)C₂H₁₀O₃
D)C₂H₄O

Question 58

Isoeugenol is the compound which gives the characteristic odor to nutmeg and contains carbon,hydrogen,and oxygen.If a 0.500 g sample of isoeugenol is combusted it gives 1.341 g of CO₂ and 0.329 g of H₂O.Isoeugenol has a molecular weight of 164 g/mol.What is the molecular formula of isoeugenol?

A)C₂HO
B)C₅H₆O
C)C₈H₄O₄
D)C₁₀H₁₂O₂

Question 59

Balance the chemical equation given below,and calculate the volume of nitrogen monoxide gas produced when 8.00 g of ammonia is reacted with 14.0 g of oxygen at 25°C? The density of nitrogen monoxide at 25°C is 1.23 g/L. ________ NH₃(g)+ ________ O₂(g)→ ________ NO(g)+ ________ H₂O(l)

A)8.54 L
B)11.1 L
C)11.5 L
D)18.8 L

Question 60

Combustion analysis of a 0.675 g sample of an unknown compound that contains only carbon,hydrogen,and oxygen gives 0.627 g of CO₂ and 1.534 g of H₂O.The molecular mass of the unknown is

A)C₃H₆O.
B)C₆H₁₂O₂.
C)C₉H₁₈O₃.
D)unable to be determined from this data.

Question 61

The following diagram represents the reaction of A (unshaded spheres)with B (shaded spheres).What is the balanced chemical equation for this reaction,and what is the limiting reactant?

A)A₂ + 2B → 2AB;A₂ is the limiting reactant.
B)A₂ + 2B → 2AB;B is the limiting reactant.
C)4A₂ + 6B → 6AB;A₂ is the limiting reactant.
D)4A₂ + 6B → 6AB;B is the limiting reactant.

Question 62

What is the balanced chemical equation for the reaction of element A (unshaded spheres)with element B (shaded spheres)as represented below?

A)A + B → AB
B)A + 3B → 2AB
C)A₂ + B₂ → AB₃
D)A₂ + 3B₂ → 2AB₃

Question 63

2-Propanol has the molecular formula C₃H₈O.Which ball and stick model shown above represents 2-propanol? [gray spheres = C,black spheres = O,unshaded spheres = H]

A)model a)
B)model b)
C)model c)
D)model d)

Question 64

What is the balanced chemical equation for the reaction of element A (unshaded spheres)with element B (shaded spheres)as represented below?

A)A + B → AB
B)4A + 2B → 4AB
C)A₂ + B₂ → A₂B
D)2A₂ + B₂ → 2A₂B

Question 65

Reaction of A (unshaded spheres)with B₂ (shaded spheres)is shown schematically in the following diagram.Which equation best describes the stoichiometry of the reaction?

A)4 A + B₂ → 8 A₂B
B)4 A + B₂ → A₄B₂
C)16 A + 4 B₂ → 8 A₂B
D)16 A + 4 B₂ → 4 A₄B₂

Question 66

The following diagram represents the reaction of A₂ (unshaded spheres)with B₂ (shaded spheres).How many moles of product can be produced from the reaction of 1.0 mol of A₂ and 1.0 mol of B₂?

A)0.5 mol of product
B)1.0 mol of product
C)2.0 mol of product
D)4.0 mol of product

Question 67

What is the stoichiometric coefficient for oxygen when the following equation is balanced using the lowest whole-number coefficients? ________ C₃H₆O₂(l)+ ________ O₂(g)→ ________ CO₂(g)+ ________ H₂O(l)

A)1
B)3
C)5
D)7

Question 68

The following diagrams represent the reaction of A₂ (shaded spheres)with B₂ (unshaded spheres).How many moles of product can be made from 1.0 mol of A₂ and 1.0 mol of B₂?

A)0.67 mol product
B)1.0 mol product
C)2.0 mol product
D)3.0 mol product

Question 69

The following diagrams represent the reaction of A₂ (shaded spheres)with B₂ (unshaded spheres).Identify the limiting reactant and write a balanced equation for the reaction.

A)A₂ is the limiting reactant;A + 4 B → AB₄.
B)A₂ is the limiting reactant;A₂ + 4 B₂ → 2 AB₄.
C)B₂ is the limiting reactant;A + 4 B → AB₄.
D)B₂ is the limiting reactant;A₂ + 4 B₂ → 2 AB_4.

Question 70

The following diagram represents the reaction of A₂ (unshaded spheres)with B (shaded spheres).What is the balanced chemical equation for this reaction,and what is the limiting reactant?

A)2A₂ + B → A₄B;A₂ is the limiting reactant.
B)2A₂ + B → A₄B;B is the limiting reactant.
C)4A₂ + 6B → 2A₄B;A₂ is the limiting reactant.
D)4A₂ + 6B → 2A₄B;B is the limiting reactant.

Question 71

Diethyl ether has the molecular formula C₄H₁₀O.Which ball and stick model shown above represents diethyl ether? [gray spheres = C,black spheres = O,unshaded spheres = H]

A)model a)
B)model b)
C)model c)
D)model d)

Question 72

What is the balanced chemical equation for the reaction of element A (unshaded spheres)with element B (shaded spheres)as represented below?

A)A + B → AB
B)2A + 3B → 2AB
C)A + B₂ → AB₃
D)2A + 3B₂ → 2AB₃

Question 73

Ethanol has the molecular formula C₂H₆O.Which ball and stick model shown above represents ethanol? [gray spheres = C,black spheres = O,unshaded spheres = H]

A)model a)
B)model b)
C)model c)
D)model d)

Question 74

The following diagram represents the reaction of A₂ (unshaded spheres)with B (shaded spheres).How many moles of product can be produced from the reaction of 1.0 mol of A₂ and 1.0 mol of B?

A)0.5 mol of product
B)1.0 mol of product
C)3.0 mol of product
D)6.0 mol of product

Question 75

Aluminum metal reacts with aqueous copper(II)sulfate to form aqueous aluminum sulfate and copper metal.What is the stoichiometric coefficient for aluminum when the chemical equation is balanced using the lowest whole-number stoichiometric coefficients?

A)1
B)2
C)3
D)4

Question 76

Reaction of A (unshaded spheres)with B₂ (shaded spheres)is shown schematically in the following diagram.Which equation best describes the stoichiometry of the reaction?

A)A₂ + 2 B → A₂B₂
B)8 A + 4 B₂ → 4 A₂B₂
C)2 A + B₂ → A₂B₂
D)4 A + 4 B₂ → 4 A₂B₂

Question 77

If unshaded spheres represent nitrogen atoms and shaded spheres represent oxygen atoms,which box represents reactants and which represents products for the reaction 2 NO₂(g)→ 2 NO(g)+ O₂(g)?

A)box (a)reactants and box (b)products
B)box (a)reactants and box (d)products
C)box (c)reactants and box (b)products
D)box (c)reactants and box (d)products

Question 78

The following diagrams represent the reaction of A₂ (shaded spheres)with B₂ (unshaded spheres).Identify the limiting reactant and write a balanced equation for the reaction.

A)A₂ is the limiting reactant;A + 3 B → AB₃.
B)A₂ is the limiting reactant;A₂ + 3 B₂ → 2 AB₃.
C)B₂ is the limiting reactant;A + 3 B → AB₃.
D)B₂ is the limiting reactant;A₂ + 3 B₂ → 2 AB_3.

Question 79

If unshaded spheres represent nitrogen atoms and shaded spheres represent oxygen atoms,which box represents reactants and which represents products for the reaction 2 N₂O(g)→ 2 N₂(g)+ O₂(g)?

A)box (a)reactants and box (c)products
B)box (a)reactants and box (d)products
C)box (b)reactants and box (c)products
D)box (b)reactants and box (d)products

Question 80

What is the balanced chemical equation for the reaction of element A (unshaded spheres)with element B (shaded spheres)as represented below?

A)A + B → AB
B)A + 3B → 3AB
C)A₂ + B → AB
D)A₂ + 2B → 2AB