Deck 3: Formulas, equations, and Moles

Question 1

Which represents one formula unit?

A)One H
B)One H₂
C)One NaH
D)All of these

Answer 1

All of these

Question 2

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

Answer 2

36.5 g of HCl

Question 3

1.00 mole of O₂ contains the same number of molecules as

A)0)667 mole of O₃.
B)1)00 mole of CH₃CO₂H.
C)2)00 mole of CH₃CH₂OH.
D)All of these

Answer 3

1)00 mole of CH₃CO₂H.

Question 4

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 5

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 6

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 7

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 8

What is the stoichiometric coefficient for oxygen when the following equation is balanced using the lowest whole-number coefficients
_____ C₃H₈O(l)+ _____ O₂(g)→ _____ CO₂(g)+ _____ H₂O(l)

A)3
B)5
C)7
D)9

Question 9

Aluminum metal reacts with iron(II)sulfide to form aluminum sulfide and iron 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 10

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 11

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

Question 12

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 13

Which is a formula mass?

A)1)0 amu of H
B)2)0 amu of H₂
C)24.0 amu of NaH
D)All of these

Question 14

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 15

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 16

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 17

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 18

Chemical equations are balanced in order to obey the law of

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

Question 19

Calcium phosphate reacts with sulfuric acid to form calcium 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

Question 20

What is the molar mass of hydrogen gas?

A)1)00 g/mol
B)2)00 g/mol
C)6)02 × 10²³ g/mol
D)1)20 × 10²³ g/mol

Question 21

How many chloride ions are in 1.50 mol of aluminum chloride?

A)3)00 chloride ions
B)4)50 chloride ions
C)9)03 × 10²³ chloride ions
D)2)71 × 10²⁴ chloride ions

Question 22

What mass of sulfur hexafluoride,SF₆,has the same number of fluorine atoms as 25.0 g of oxygen difluoride,OF₂?

A)0)901 g
B)8)33 g
C)22.5 g
D)203 g

Question 23

Which of the following has the greatest mass?

A)6)02 × 10²³ molecules of O₂
B)16.0 g of O₂
C)0)500 mol of O₂
D)All of these have the same mass.

Question 24

How many moles are in 1.50 g of ethanol,CH₃CH₂OH?

A)0)0145 mol
B)0)0326 mol
C)30.7 mol
D)69.0 mol

Question 25

How many cations 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 26

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)14.9 g
D)29.8 g

Question 27

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 28

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

A)0)0801 oxygen atoms
B)9)85 × 10²⁰ oxygen atoms
C)6)90 × 10²¹ oxygen atoms
D)4)83 × 10²² oxygen atoms

Question 29

How many iron(II)ions,Fe²⁺ 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

Question 30

What mass of dinitrogen monoxide,N₂O,contains the same number of molecules as 3.00 g of trichlorofluoromethane,CCl₃F?

A)0)106 g
B)0)961 g
C)1)04 g
D)9)37 g

Question 31

How many moles of CuO can be produced from 0.450 mol of Cu₂O in the following reaction?
2 Cu₂O(s)+ O₂(g)→ 4 CuO(s)

A)0)225 mol
B)0)450 mol
C)0)900 mol
D)1)80 mol

Question 32

How many anions are in 0.500 g of MgBr₂?

A)1)64 × 10²¹ anions
B)3)27 × 10²¹ anions
C)2)22 × 10²⁶ anions
D)4)43 × 10²⁶ anions

Question 33

How many moles of BCl₃ are needed to produce 25.0 g of HCl(aq)in the following reaction?
BCl₃(g)+ 3 H₂O(l)→ 3 HCl(aq)+ B(OH)₃(aq)

A)0)229 mol
B)0)686 mol
C)2)06 mol
D)4)38 mol

Question 34

Which of the following has the smallest mass?

A)3)50 × 10²³ molecules of I₂
B)85.0 g of Cl₂
C)2)50 mol of F₂
D)0)050 kg of Br₂

Question 35

What is the mass of 0.500 mol of dichlorodifluoromethane,CF₂Cl₂?

A)4)14 × 10^-3 g
B)60.5 g
C)121 g
D)242 g

Question 36

Balance the chemical equation given below,and determine the number of moles of iodine that reacts with 10.0 g of aluminum.
_____ Al(s)+ _____ I₂(s)→ _____ Al₂I₆(s)

A)0)247 mol
B)0)556 mol
C)0)741 mol
D)1)11 mol

Question 37

What is the mass of 8.50 × 10²² molecules of NH₃?

A)0)00830 g
B)0)417 g
C)2)40 g
D)120 g

Question 38

What is the mass of a single chlorine molecule,Cl₂?

A)5)887 × 10^-23 g
B)1)177 × 10^-22 g
C)35.45 g
D)70.90 g

Question 39

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 40

What is the molar mass of butane if 5.19 × 10¹⁶ molecules of butane weigh 5.00 μg?

A)58.0 g/mol
B)172 g/mol
C)232 g/mol
D)431 g/mol

Question 41

5.0 g of iron is reacted with 5.0 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)85 g of H₂O are left over.
C)Mass is conserved in this reaction.
D)Water is the limiting reactant.

Question 42

When 5.00 × 10²² molecules of ammonia react with 4.00 × 10²² molecules of oxygen according to the chemical equation shown below,how many grams of nitrogen gas are produced?
4 NH₃(g)+ 3 O₂(g)→ 2 N₂(g)+ 6 H₂O(g)

A)1)16 g
B)1)24 g
C)2)79 g
D)4)65 g

Question 43

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

A)0)0877 g
B)1)26 g
C)3)78 g
D)11.4 g

Question 44

Which substance is the limiting reactant when 2.0 g of sulfur reacts with 3.0 g of oxygen and 4.0 g of sodium hydroxide according to the following chemical equation:
2 S(s)+ 3 O₂(g)+ 4 NaOH(aq)→ 2 Na₂SO₄(aq)+ 2 H₂O(l)

A)S(s)
B)O_2(g)
C)NaOH (aq)
D)None of these substances is the limiting reactant.

Question 45

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 46

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 47

When silver nitrate reacts with barium chloride,silver chloride and barium nitrate are formed.How many grams of silver chloride are formed when 10.0 g of silver nitrate reacts with 15.0 g of barium chloride?

A)8)44 g
B)9)40 g
C)11.9 g
D)18.8 g

Question 48

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 49

Molarity is defined as

A)moles of solute per liter of solution.
B)moles of solute per liter of solvent.
C)moles of solvent per liter of solution.
D)moles of solvent per liter of solvent.

Question 50

When 10.0 g of calcium metal is reacted with water,5.00 g of calcium hydroxide is produced.Using the following balanced equation,calculate the percent yield for the reaction?
Ca(s)+ 2 H₂O(l)→ Ca(OH)₂(aq)+ H₂(g)

A)13.5%
B)27.1%
C)50.0%
D)92.4%

Question 51

If the percent yield for the following reaction is 65.0%,how many grams of KClO₃ are needed to produce 42.0 g of O₂?
2 KClO₃(s)→ 2 KCl(s)+ 3 O₂(g)

A)69.7 g
B)107 g
C)165 g
D)371 g

Question 52

Balance the chemical equation given below,and calculate the volume of nitrogen monoxide gas produced when 8.00 g of ammonia is reacted with 12.0 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)7)32 L
B)11.1 L
C)11.5 L
D)18.8 L

Question 53

Dinitrogen monoxide gas decomposes to form nitrogen gas and oxygen gas.How many grams of oxygen are formed when 5.00 g of dinitrogen monoxide decomposes?

A)0)550 g
B)1)82 g
C)3)64 g
D)7)27 g

Question 54

How many grams of AgNO₃ are needed to make 250.mL of a solution that is 0.135 M?

A)0)0917 g
B)0)174 g
C)5)73 g
D)9)17 g

Question 55

The density of ethanol,C₂H₅OH,is 0.789 g/mL.How many milliliters of ethanol are needed to produce 10.0 g of CO₂ according to the following chemical equation?
C₂H₅OH(l)+ 3 O₂(g)→ 2 CO₂(g)+ 3 H₂O(l)

A)4)12 mL
B)6)63 mL
C)13.2 mL
D)26.5 mL

Question 56

10 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 15 g.

Question 57

What is the concentration of FeCl₃ in a solution prepared by dissolving 10.0 g of FeCl₃ in enough water to make 275 mL of solution?

A)2)24 × 10^-4 M
B)0)224 M
C)4)46 M
D)4)46 × 10³ M

Question 58

If the percent yield for the following reaction is 75.0%,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)30.8 g
B)41.1 g
C)54.8 g
D)69.3 g

Question 59

What volume of a 0.540 M NaOH solution contains 15.5 g of NaOH?

A)0)209 L
B)0)718 L
C)1)39 L
D)4)78 L

Question 60

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 61

A student prepared a stock solution by dissolving 20.0 g of KOH in enough water to make 150.mL of solution.She then took 15.0 mL of the stock solution and diluted it with enough water to make 65.0 mL of a final solution.What is the concentration of KOH for the final solution?

A)0)548 M
B)0)713 M
C)1)40 M
D)1)82 M

Question 62

What is the concentration of HCl in the final solution when 65 mL of a 12 M HCl solution is diluted with pure water to a total volume of 0.15 L?

A)2)8 × 10^-2 M
B)5)2 M
C)28 M
D)5)2 × 10³ M

Question 63

How many milliliters of 0.260 M Na₂S are needed to react with 25.00 mL of 0.315 M AgNO₃?
Na₂S(aq)+ 2 AgNO₃(aq)→ 2 NaNO₃(aq)+ Ag₂S(s)

A)15.1 mL
B)30.3 mL
C)41.3 mL
D)60.6 mL

Question 64

Balance the chemical equation given below,and determine the number of milliliters of 0.0300 M phosphoric acid required to neutralize 25.00 mL of 0.0150 M calcium hydroxide.
_____ Ca(OH)₂(aq)+ _____ H₃PO₄(aq)→ _____ Ca₃(PO₄)₂(s)+ _____ H₂O(l)

A)1)69 mL
B)8)33 mL
C)12.5 mL
D)18.8 mL

Question 65

Which contains the greatest number of chloride ions?

A)25 mL of 2.0 M NaCl
B)50 mL of 1.0 M CaCl₂
C)10 mL of 2.5 M FeCl₃
D)All contain the same number of chloride ions.

Question 66

If the reaction of phosphate ion with water is ignored,what is the total concentration of ions in a solution prepared by dissolving 3.00 g of K₃PO₄ in enough water to make 350.mL of solution?

A)0)0101 M
B)0)0404 M
C)0)162 M
D)0)323 M

Question 67

Which statement about diluted solutions is false? When a solution is diluted

A)the concentration of the solution decreases.
B)the molarity of the solution decreases.
C)the number of moles of solute remains unchanged.
D)the number of moles of solvent remains unchanged.

Question 68

How many milliliters of 0.550 M hydriodic acid are needed to react with 25.00 mL of 0.217 M CsOH?
HI(aq)+ CsOH(aq)→ CsI(aq)+ H₂O(l)

A)0)0158 mL
B)0)101 mL
C)9)86 mL
D)63.4 mL

Question 69

In an acid-base neutralization reaction 23.74 mL of 0.500 M potassium hydroxide reacts with 50.00 mL of sulfuric acid solution.What is the concentration of the H₂SO₄ solution?

A)0)119 M
B)0)237 M
C)0)475 M
D)2)11 M

Question 70

How many milliliters of a 9.0 M H₂SO₄ solution are needed to make 0.25 L of a 3.5 M H₂SO₄ solution?

A)0)097 mL
B)0)64 mL
C)97 mL
D)640 mL

Question 71

How many milliliters of 0.200 M FeCl₃ are needed to react with an excess of Na₂S to produce 2.75 g of Fe₂S₃ if the percent yield for the reaction is 65.0%?
3 Na₂S(aq)+ 2 FeCl₃(aq)→ Fe₂S₃(s)+ 6 NaCl(aq)

A)50.9 mL
B)86.0 mL
C)102 mL
D)203 mL

Question 72

How many grams of CaCl₂ are formed when 35.00 mL of 0.00237 M Ca(OH)₂ reacts with excess Cl₂ gas?
2 Ca(OH)₂(aq)+ 2 Cl₂(g)→ Ca(OCl)₂(aq)+ CaCl₂(s)+ 2 H₂O(l)

A)0)00460 g
B)0)00921 g
C)0)0184 g
D)0)0217 g

Question 73

When 200.mL of ç M hydrochloric acid is added to 125 mL of 1.75 × 10^-4 M Mg(OH)₂,the resulting solution will be

A)acidic.
B)basic.
C)neutral.
D)It is impossible to tell from the information given.

Question 74

What is the concentration of an AlCl₃ solution if 150.mL of the solution contains 250.mg of Cl^- ion?

A)1)57 × 10^-2 M
B)3)75 × 10^-2 M
C)4)70 × 10^-2 M
D)1)41 × 10^-1 M

Question 75

How many mL of a 0.175 M FeCl₃ solution are needed to make 250.mL of a solution that is
0)300 M in Cl^- ion?

A)0)429 mL
B)143 mL
C)429 mL
D)It is not possible to make a more concentrated solution from a less concentrated solution.

Question 76

A student dissolved 3.00 g of Co(NO₃)₂ in enough water to make 100.mL of stock solution.He took 4.00 mL of the solution then diluted it with water to give 275 mL of a final solution.How many grams of NO₃^- ion are there in the final solution?

A)0)0148 g
B)0)0296 g
C)0)0407 g
D)0)0813 g

Question 77

What is the concentration of NO₃^- ions in a solution prepared by dissolving 15.0 g of Ca(NO₃)₂ in enough water to produce 300.mL of solution?

A)0)152 M
B)0)305 M
C)0)403 M
D)0)609 M

Question 78

If 100.mL of 0.100 M Na₂SO₄ is added to 200.mL of 0.150 M NaCl,what is the concentration of Na⁺ ions in the final solution? Assume that the volumes are additive.

A)0)133 M
B)0)167 M
C)0)250 M
D)0)350 M

Question 79

When 125 mL of 0.500 M AgNO₃ is added to 100.mL of 0.300 M NH₄Cl,how many grams of AgCl are formed?
AgNO₃(aq)+ NH₄Cl(aq)→ AgCl(s)+ NH₄NO₃(aq)

A)4)30 g
B)8)96 g
C)13.3 g
D)25.8 g

Question 80

When a 1.0 M solution of NaCl at 25°C is heated to 55°C,the

A)density decreases and the molarity decreases.
B)density decreases and the molarity increases.
C)density increases and the molarity decreases.
D)density increases and the molarity increases.