Deck 7: Chemical Reactions and Quantities

Question 1

In the following reaction, when the equation is correctly balanced, what is the correct coefficient for H₂?
Fe(s) + HCl(aq) → FeCl₃(aq) + H₂(g)

A)1
B)2
C)3
D)4
E)5

Answer 1

3

Question 2

In any balanced chemical equation, the number of each type of atom on both sides of the equation is

A)doubled.
B)the same.
C)decreased by one.
D)increased by one.
E)dependent on the temperature.

Answer 2

the same.

Question 3

In the following reaction, when the equation is correctly balanced, what is the correct coefficient for aluminum chloride?
Al(s) + Cl₂(g) → AlCl₃(s)

A)1
B)2
C)3
D)4
E)5

Answer 3

2

Question 4

Which of the following is an oxidation-reduction reaction?

A)CaCl₂+ Na₂SO₄→ CaSO₄+ 2NaCl
B)KOH + HNO₃→ H₂O + KNO₃
C)N₂ + O₂ → 2NO
D)AgNO₃+ NaCl → AgCl + NaNO₃
E)Al₂(SO₄)3 + 6KOH → 2Al(OH)3 + 3K₂SO₄

Question 5

Pentane (C₅H₁₂) reacts with oxygen (O₂) to form carbon dioxide (CO₂) and water (H₂O) according to the following reaction. Answer the question(s) that follow about this reaction.
C₅H₁₂ + ? O₂ → ? CO₂ + ? H₂O
What is the coefficient for carbon dioxide in the balanced equation?

A)2
B)4
C)5
D)6
E)8

Question 6

In the following reaction, when the equation is correctly balanced, what is the correct coefficient for sodium chloride?
Pb(NO₃)₂(aq) + NaCl(aq) → PbCl₂(s) + NaNO₃(aq)

A)1
B)2
C)3
D)4
E)5

Question 7

Which of the following gives the balanced equation for this reaction?
K₃PO₄ + Ca(NO₃)₂ → Ca₃(PO₄)₂ + KNO₃

A)KPO₄+ CaNO₃+ KNO₃
B)K₃PO₄+ Ca(NO₃)₂→ Ca₃(PO₄)₂+ 3KNO₃
C)2K₃PO₄+ Ca(NO₃)₂→ Ca₃(PO₄)₂+ 6KNO₃
D)2K₃PO₄+ 3Ca(NO₃)₂→ Ca₃(PO₄)₂+ 6KNO₃
E)K₃PO₄+ Ca(NO₃)₂→ Ca₃(PO₄)₂+ KNO₃

Question 8

The reaction of carbon with oxygen to produce carbon monoxide is an example of which class of reaction?
2C(s) + O₂(g) → 2CO(g)

A)single replacement
B)double replacement
C)combination
D)catalytic
E)endothermic

Question 9

What is the coefficient of hydrogen, H₂, when the following equation is balanced?
Al + H₂SO₄ → Al₂(SO₄)₃ + ? H₂

A)1
B)2
C)3
D)4
E)5

Question 10

Which of the following correctly gives the best coefficients for the reaction below? N₂H₄ + H₂O₂ → N₂ + H₂O

A)1, 1, 1 ,1
B)1, 2, 1, 4
C)2, 4, 2, 8
D)1, 4, 1, 4
E)2, 4, 2, 4

Question 11

In a ________ reaction, two or more elements or compounds form one product.

A)decomposition
B)single replacement
C)dehydration
D)double replacement
E)combination

Question 12

The following reaction takes place when an electric current is passed through water. It is an example of a ________ reaction. 2H₂O → 2H₂ + O₂

A)combination
B)single replacement
C)dehydration
D)decomposition
E)double replacement

Question 13

Pentane (C₅H₁₂) reacts with oxygen (O₂) to form carbon dioxide (CO₂) and water (H₂O) according to the following reaction. Answer the question(s) that follow about this reaction.
C₅H₁₂ + ? O₂ → ? CO₂ + ? H₂O
What is the coefficient for oxygen in the balanced equation?

A)2
B)4
C)5
D)6
E)8

Question 14

In this reaction, what is the coefficient for calcium oxide? CaO(s) + CO₂(g) → CaCO₃(s)

A)1
B)2
C)3
D)4
E)5

Question 15

What is the classification for this reaction?
SO₃ (g) + H₂O (l) → H₂SO₄(l)

A)decomposition
B)combination
C)replacement
D)double replacement
E)oxidation reduction

Question 16

What coefficient is placed in front of O₂ to complete the balancing of the following equation? C₅H₈ + ? O₂ → 5CO₂ + 4H₂O

A)1
B)3
C)5
D)7
E)9

Question 17

A chemical equation is balanced when

A)the total number of molecules is the same in reactants and products.
B)the total number of ions is the same in reactants and products.
C)the sum of the coefficients of the reactants is equal to the sum of the coefficients of the products.
D)the number of atoms of each element is the same in reactants and products.
E)the charge on each atom is the same in reactants and products.

Question 18

Pentane (C₅H₁₂) reacts with oxygen (O₂) to form carbon dioxide (CO₂) and water (H₂O) according to the following reaction. Answer the question(s) that follow about this reaction.
C₅H₁₂ + ? O₂ → ? CO₂ + ? H₂O
What is the coefficient for water in the balanced equation?

A)2
B)4
C)5
D)6
E)8

Question 19

The reaction of methane with oxygen to produce carbon dioxide and water is an example of which class of reaction?
CH₄(g) + 2O₂(g) → CO₂(g) + 2H₂O(g)

A)single replacement
B)double replacement
C)combination
D)oxidation
E)endothermic

Question 20

What is the classification for this unbalanced reaction?
Fe + HCl → FeCl₃ + H₂

A)dehydration
B)combination
C)decomposition
D)single replacement
E)double replacement

Question 21

The molar mass of potassium is

A)19 g.
B)31.0 g.
C)6.02 × 10²³ grams.
D)39.1 g.
E)15g.

Question 22

How many moles of water, H₂O, are present in 75.0 g of H₂O?

A)4.41 moles
B)4.16 moles
C)75.0 moles
D)7.50 moles
E)1.35 × 10³ moles

Question 23

0.100 mole of lithium has a mass of

A)3.00 g.
B)0.300 g.
C)6.94 g.
D)0.694 g.
E)0.700 g.

Question 24

How many atoms of neon are present in 1.30 moles of neon?

A)3.15 × 10²³ atoms
B)4.63 × 10²³ atoms
C)7.83 × 10²³ atoms
D)6.02 × 10²³ atoms
E)7.83 × 10²⁴ atoms

Question 25

What is the molar mass of sodium phosphate, Na₃PO₄ ?

A)119 g
B)308 g
C)164 g
D)226 g
E)354 g

Question 26

How many moles of carbon atoms are there in 0.500 mole of C₂H₆?

A)0.500 moles
B)1.00 moles
C)3.00 moles
D)6.02 × 10²³ moles
E)4.00 moles

Question 27

How many hydrogen atoms are present in 75.0 g of H₂O?

A)75.0 atoms
B)4.17 atoms
C)7.53 × 10²⁴ atoms
D)2.51 × 10²⁴ atoms
E)5.02 × 10²⁴ atoms

Question 28

In an oxidation-reduction reaction, the substance reduced always

A)takes on oxygen atoms.
B)shows a loss of electrons.
C)gives up hydrogen atoms.
D)shows a gain of electrons.
E)becomes a charged species.

Question 29

How many moles of iron are present in 3.15 × 10²⁴ atoms of iron?

A)5.23 moles
B)1.90 moles
C)292 moles
D)0.523 moles
E)1.90 × 10⁴⁸ moles

Question 30

Which of the following describes an oxidation reaction?

A)loss of electrons or loss of oxygen
B)loss of electrons or gain of oxygen
C)loss of electrons or gain of hydrogen
D)gain of electrons or gain of oxygen
E)gain of electrons or loss of H

Question 31

Avogadro's number is the number of

A)particles in 1 mole of a substance.
B)amu in 1 mole of a substance.
C)grams in 1 mole of a substance.
D)moles in 6.02 × 10²³ grams of an element.
E)moles in 6.02 × 10²³ amu of an element.

Question 32

Calculate the molar mass of magnesium chloride, MgCl₂ .

A)24.3 g
B)95.2 g
C)125.9 g
D)59.8 g
E)70.0 g

Question 33

In an oxidation-reduction reaction, the substance oxidized always

A)takes on oxygen atoms.
B)shows a loss of electrons.
C)gives up hydrogen atoms.
D)shows a gain of electrons.
E)becomes a charged species.

Question 34

One mole of helium gas has a mass of

A)1.00 g.
B)2.00 g.
C)3.00 g.
D)4.00 g.
E)8.00 g.

Question 35

One mole of particles of any substance contains how many particles?

A)10⁶
B)3 × 10^-10
C)3 × 10¹⁰
D)6.02 × 10²³
E)6.02 × 10^-23

Question 36

How many molecules of water, H₂O, are present in 75.0 g of H₂O?

A)75.0 molecules
B)4.17 molecules
C)7.53 × 10²⁴ molecules
D)2.51 × 10²⁴ molecules
E)5.02 × 10²⁴ molecules

Question 37

In this reaction, what is the substance oxidized? Zn(s) + 2 HCl(aq) → ZnCl₂(aq) + H₂(g)

A)chlorine
B)zinc chloride
C)hydrogen
D)zinc
E)oxygen

Question 38

What is oxidized and what is reduced in the following reaction?
2Al(s) +3Br₂(g) → 2AlBr₃(s)

A)Al is oxidized and Br₂ is reduced.
B)AlBr₃ is reduced and Br₂ is oxidized.
C)Al is reduced and Br₂ isoxidized.
D)AlBr₃ is reduced and Al is oxidized.
E)AlBr₃ is oxidized and Al is reduced.

Question 39

Calculate the molar mass of potassium chloride, KCl.

A)74.6 g
B)54.5 g
C)6.74 g
D)67.4 g
E)19.0 g

Question 40

What is the molar mass of copper(II) sulfate, CuSO₄ ?

A)16.0 g
B)63.6 g
C)111.6 g
D)159.6 g
E)319.2 g

Question 41

The molar mass of C₃H₈O₂ is

A)76.0 g.
B)60.0 g.
C)29.0 g.
D)69.0 g.
E)52.0 g.

Question 42

When 4 moles of aluminum are allowed to react with an excess of chlorine gas, Cl₂ , how many moles of aluminum chloride are produced?

A)1 mole
B)2 moles
C)3 moles
D)4 moles
E)5 moles

Question 43

What is the molar mass of Mg₃(PO₄)₂ , a substance formerly used in medicine as an antacid?

A)71.3 g
B)118 g
C)150. g
D)214 g
E)263 g

Question 44

In the reaction of nitrogen gas, N₂, with hydrogen gas, H₂, to form ammonia gas, NH₃ , how many moles of hydrogen are needed to react with two moles of nitrogen?

A)2 moles
B)4 moles
C)6 moles
D)8 moles
E)10 moles

Question 45

One mole of neon atoms has a mass of

A)6.02 × 10²³ grams.
B)14.0 g.
C)10.0 g.
D)20.2 g.
E)30.2 g.

Question 46

For the question(s) that follow, consider the following equation.
2Mg + O₂ → 2MgO
How many grams of MgO are produced when 40.0 grams of O₂ react completely with Mg?

A)30.4 g
B)50.4 g
C)60.8 g
D)101 g
E)201 g

Question 47

For the question(s) that follow, consider the following balanced equation.
Mg₃N₂(s) + 6H₂O(l) → 3Mg (OH)₂(s) + 2NH₃(g)
When 2 moles of Mg₃ N₂ are allowed to react, how many moles of H₂O also react?

A)1 mole
B)4 moles
C)6 moles
D)8 moles
E)12 moles

Question 48

For the question(s) that follow, consider the following balanced equation.
Mg₃N₂(s) + 6H₂O(l) → 3Mg (OH)₂(s) + 2NH₃(g)
What is the correct form of the conversion factor needed to convert the number of moles of H₂O to the number of moles of NH₃ produced?

A)
B)
C)
D)
E)

Question 49

Given the following equation, what is the correct form of the conversion factor needed to convert the number of moles of O₂ to the number of moles of Fe₂O₃ produced? 4Fe(s) + 3O₂ (g) → 2Fe₂O₃(s)

A)
B)
C)
D)
E)

Question 50

How many moles of magnesium are needed to react with 0.50 mole of O₂?

A)0.50 mole
B)1.0 moles
C)2.0 moles
D)3.0 moles
E)4.0 moles

Question 51

1.25 moles of PbO₂ have a mass of

A)191 g.
B)279 g.
C)178 g.
D)239 g.
E)299 g.

Question 52

The molar mass of calcium hydroxide, Ca(OH)₂ , is

A)58.1 g.
B)57.1 g.
C)74.1 g.
D)114.2 g.
E)38.0 g.

Question 53

For the question(s) that follow, consider the following equation.
2Mg + O₂ → 2MgO
The number of moles of oxygen gas needed to react with 4.0 moles of Mg is

A)1.0 mole.
B)2.0 moles.
C)3.0 moles.
D)4.0 moles.
E)6.0 moles.

Question 54

3.00 moles of NO₂ have a mass of

A)138 g.
B)46.0 g.
C)30.0 g.
D)90.0 g.
E)45.0 g.

Question 55

How many moles of K₂ SO₄ are in 15.0 g of K₂ SO₄ ?

A)0.172 moles
B)2.61 × 10³ moles
C)0.111 moles
D)0.0861 moles
E)0.119 moles

Question 56

What is the molar mass of sucrose (C₁₂H₂₂O₁₁)?

A)29.0 g
B)50.2 g
C)210 g
D)342 g
E)182 g

Question 57

How many grams of glucose (C₆H₁₂O₆) are in 3.55 moles of glucose?

A)180. g
B)639 g
C)103 g
D)426 g
E)50.7 g

Question 58

How many grams of Fe₂O₃ are there in 0.500 mole of Fe₂O₃ ?

A)79.9 g
B)35.9 g
C)63.8 g
D)51.9 g
E)160. g

Question 59

For the question(s) that follow, consider the following equation.
2Mg + O₂ → 2MgO
The number of moles of MgO produced when 0.20 mole of O2 reacts completely is

A)0.10 mole.
B)0.20 mole.
C)0.40 mole.
D)0.60 mole.
E)0.80 mole.

Question 60

4.00 moles of sodium have a mass of

A)4.60 g.
B)11.0 g.
C)23.0 g.
D)44.0 g.
E)92.0 g.

Question 61

How many grams of NO are required to produce 145 g of N₂ in the following reaction? 4NH₃(g) + 6NO(g) → 5N₂(g) + 6H₂O(l)

A)186 g
B)155 g
C)125 g
D)129 g
E)145 g

Question 62

For the reaction: 2H₂O(l) + 137 kcal → 2H₂ (g) + O₂ (g), how many kcal are needed to react 50.0 g H₂O(l)?

A)380. kcal
B)137 kcal
C)274 kcal
D)190. kcal
E)760. kcal

Question 63

When 85.0 g of CH₄ are mixed with 160. g of O₂ the limiting reactant is CH₄ + 2O₂ → CO₂ + 2H₂O

A)CH₄
B)O₂.
C)CO₂.
D)H₂O.

Question 64

When 36.0 g of H₂O react, how many grams of NH₃ are produced?

A)34.0 g
B)10.0 g
C)5.67 g
D)11.3 g
E)102 g

Question 65

How many grams of hydrogen are needed to produce 1.80 g of water according to this equation? 2H₂ + O₂ → 2H₂O

A)0.100 g
B)0.180 g
C)0.200 g
D)2.00 g
E)4.00 g

Question 66

When 10.0 g of NH₃ reacts, the actual yield of N₂ is 8.50 g. What is the percent yield? 4NH₃(g) + 6NO(g) → 5N₂(g) + 6H₂O(l)

A)85.0%
B)51.5%
C)20.6%
D)41.3%
E)8.5%

Question 67

When 85.0 g of CH₄ are mixed with 160. g of O₂ what is the maximum amount of CO₂ that can be produced? CH₄ + 2O₂ → CO₂ + 2H₂O

A)2.50 moles
B)5.00 moles
C)5.31 moles
D)7.81 moles

Question 68

What type of reaction is: CH₄ + 2O₂ → CO₂ + 2H₂O + 218 kcal?

A)an endothermic reaction
B)an exothermic reaction
C)a single replacement reaction
D)a combination reaction
E)a decomposition reaction

Question 69

Find the mass of AlCl₃ that is produced when 25.0 grams of Al₂O₃ react with excess HCl according to the following equation. Al₂O₃(s) + 6HCl(aq) → 2AlCl₃(aq) + 3H₂O(l)

A)155 g
B)72.9 g
C)65.4 g
D)32.6 g
E)16.3 g

Question 70

For the reaction: 2H₂O(l) + 137 kcal → 2H₂ (g) + O₂ (g), how many kcal are needed to form 2.00 moles O₂ (g)?

A)68.5 kcal
B)137 kcal
C)274 kcal
D)190. kcal
E)548 kcal

Question 71

How many grams of CO₂ are produced from 125 g of O₂ and excess CH₄ ?
CH₄ + 2O₂ → CO₂ + 2H₂O

A)125 g of CO₂
B)62.5 g of CO₂
C)172 g of CO₂
D)85.9 g of CO₂
E)250. g of CO₂

Question 72

How many grams of N₂ are produced from 100. g of NH₃ in the following reaction? 4NH₃(g) + 6NO(g) → 5N₂(g) + 6H₂O(l)

A)165 g
B)132 g
C)125 g
D)206 g
E)7.35 g

Question 73

When 3.05 moles of CH₄ are mixed with 5.03 moles of O₂ the limiting reactant is CH₄ + 2O₂ → CO₂ + 2H₂O

A)CH₄
B)O₂.
C)CO₂.
D)H₂O.

Question 74

How many kcal are produced when 32.0 g of CH₄ react? CH₄ + 2O₂ → CO₂ + 2H₂O + 218 kcal

A)218 kcal
B)109 kcal
C)436 kcal
D)6.81 kcal
E)698 kcal

Question 75

When 60.0 g of CH₄ reacts with excess O₂, the actual yield of CO₂ is 112 g. What is the percent yield? CH₄ + 2O₂ → CO₂ + 2H₂O

A)53.6 %
B)187 %
C)67.9 %
D)46.4 %

Question 76

If the reaction shown below is exothermic, the energy level of the reactants is H₂ + O₂ → 2H₂O

A)lower than that of the products.
B)higher than that of the products.
C)the same as that of the products.
D)possibly lower, possibly higher than that of the products.
E)higher than the activation energy of the reaction.

Question 77

Find the mass of AlCl₃ that is produced when 10.0 grams of Al₂O₃ react with 10.0 g of HCl according to the following equation. Al₂O₃(s) + 6HCl(aq) → 2AlCl₃(aq) + 3H₂O(aq)

A)16.2 g
B)20.0 g
C)12.2 g
D)10.0 g
E)6.10 g

Question 78

In the reaction of silver nitrate with sodium chloride, how many grams of silver chloride will be produced from 100. g of silver nitrate when it is mixed with an excess of sodium chloride? The equation for the reaction is below. AgNO₃(aq) + NaCl(aq) → AgCl(s) + NaNO₃(aq)

A)107.9 g
B)169.9 g
C)84.4 g
D)0.589 g
E)58.9 g

Question 79

For the question(s) that follow, consider the following balanced equation.
Mg₃
N₂(s) + 6H₂O(l) → 3Mg (OH)₂(s) + 2NH₃(g)
How many grams of H₂O are needed to produce 150 g of Mg(OH)₂ ?

A)46 g
B)18 g
C)130 g
D)93 g
E)23 g

Question 80

In an endothermic reaction

A)heat flows out of the system.
B)energy is absorbed by the system.
C)the temperature of the system increases.
D)the products have less energy that the reactants.
E)the products have the same energy that the reactants.