Deck 5: Chemical Reactions

Question 1

Consider the reactants and propose the right side of the equation.
Mg + H₂SO₄ $\rarr$ ______

A) no reaction
B) MgHSO₄
C) MgSO₄ + H₂
D) MgH₂ + SO₄

Answer 1

MgSO₄ + H₂

Question 2

Single replacement reactions are always

A) redox reactions.
B) nonredox reactions.
C) combination reactions.
D) decomposition reactions.

Answer 2

redox reactions.

Question 3

In which of the following does an element have an oxidation number of +4?

A) TiO₂
B) HBr
C) SO₃
D)

Answer 3

TiO₂

Question 4

What is the oxidation number of Cl in HClO₃?

A) +2
B) +3
C) +4
D) +5

Question 5

Which of the following contains the metal with the highest oxidation number?

A) CaCl₂
B) NaCl
C) FeCl₃
D) CuCl₂

Question 6

What substance is reduced in the following reaction?
4HCl + MnO₂ $\rarr$ Cl₂ + 2H₂O + MnCl₂

A) Cl in HCl
B) Mn in MnO₂
C) H in HCl
D) O in MnO₂

Question 7

Which of the following is an oxidizing agent?

A) O₂
B) H₂
C) H₂O
D) HCl

Question 8

Which species would be considered a spectator ion based on the following equation?
Ba²⁺ + 2NO₃^- + 2Na⁺ + SO₄²⁺ $\rarr$ BaSO_4(s) + 2NO₃^- + 2Na⁺

A) Ba²⁺
B) SO₄²⁺
C) BaSO₄
D) 2NO₃^-

Question 9

What is the oxidizing agent in the following reaction?
4HCl + MnO₂ $\rarr$ Cl₂ + 2H₂O + MnCl₂

A) HCl
B) Cl₂
C) MnO₂
D) MnCl₂

Question 10

What is the oxidation number of Br in
?

A) (-1)
B) +1
C) +2
D) +3

Question 11

Propane,C₃H₈,burns to produce carbon dioxide and water by the equation below.What is the coefficient in front of the carbon dioxide in the balanced equation?
C₃H₈ + O₂ $\rarr$ CO₂ + H₂O

A) 1
B) 2
C) 3
D) 6

Question 12

A REDOX reaction can also be a(n)

A) combination reaction.
B) single replacement reaction.
C) decomposition reaction.
D) More than one response is correct.

Question 13

What substance is oxidized in the following reaction?
4HCl + MnO₂ $\rarr$ Cl₂ + 2H₂O + MnCl₂

A) Cl in HCl
B) Mn in MnO₂
C) H in HCl
D) O in MnO₂

Question 14

Which set of coefficients balances the equation?
_____ CH₄ $\rarr$ ______C₃H₈ +_____H₂

A) 3,1,1
B) 3,2,1
C) 3,1,2
D) 6,2,2

Question 15

Which of the following statements is not true about the reaction?
2 CH₄ + 3 O₂ $\rarr$ 2 CO₂ + 4 H₂O

A) Water is a reactant.
B) Methane and carbon dioxide are products.
C) Methane is a product.
D) Water and carbon dioxide are products.

Question 16

When the equation below is properly balanced,what coefficient is in front of KCl?
KClO₃ $\rarr$ KCl + O₂

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

Question 17

Which of the following equations (not balanced)represents an oxidation-reduction process?

A) AgNO₃ + NaCl $\rarr$ AgCl + NaNO₃
B) C + O₂ $\rarr$ CO₂
C) C₂H₄ + O₂ $\rarr$ CO₂ + H₂O
D) more than one response is correct

Question 18

Which of the following reactions is correctly balanced?

A) N₂ + H $\rarr$ 2NH₃
B) 2H₂O + C $\rarr$ CO + 2H₂
C) Zn + 2HCl $\rarr$ H₂ + ZnCl₂
D) CO + O₂ $\rarr$ CO₂

Question 19

What is the oxidation number of Mn in KMnO₄?

A) +9
B) +5
C) +7
D) +4

Question 20

Consider the reactants in the partial equation given.Which choice is a product?
H₃PO₄ + Sr(OH)₂ $\rarr$ _______

A) no reaction
B) SrH₃PO₅
C) SrH₅PO₆
D) Sr₃(PO₄)₂

Question 21

Acetylene,C₂H₂,burns according to the following reaction: C₂H₂+5O₂ $\rarr$ 4CO₂+2H₂O.Suppose 1.20 g of C₂H₂ is mixed with 3.50 g of O₂ in a closed,steel container,and the mixture is ignited.What substances will be found in the mixture left when the burning is complete?

A) CO₂ and H₂
B) O₂,CO₂,and H₂O
C) C₂H₂,CO₂,and H₂O
D) O₂,C₂H₂,CO₂,and H₂O

Question 22

The Haber Process is a method for the production of ammonia,an important chemical intermediate.The reaction for this process is
N₂ + 3H₂ $\rarr$ 2NH₃
According to the mole interpretation,how many grams of NH₃ could be produced by the complete reaction of 2.80 grams of N₂ and excess H₂?

A) 34.0
B) 17.0
C) 3.10
D) 3.40

Question 23

Oxygen can be prepared in the lab by heating potassium chlorate in the presence of a catalyst.The reaction is 2KClO₃ $\rarr$ 2KCl + 3O₂.How many moles of O₂ could be obtained from one mole of KClO₃?

A) 1.5
B) 3.0
C) 1.0
D) 2.0

Question 24

Which of the following is a single replacement reaction?

A) CuO + H₂ $\rarr$ Cu + H₂O
B) HBr + KOH $\rarr$ H₂O + KBr
C) SO₂ + H₂O $\rarr$ H₂SO₃
D) 2HI $\rarr$ I₂ + H₂

Question 25

Barium sulfate is often ingested to aid in the diagnosis of GI tract disorders.The equation for its production is Ba²⁺ + SO $\rarr$ BaSO₄(s).What type of equation is this?

A) a total ionic equation
B) a full equation
C) an oxidation-reduction equation
D) a net ionic equation

Question 26

In the equation for an endothermic reaction,the word "heat" appears

A) on the right side.
B) on the left side.
C) on both sides.
D) on neither side.

Question 27

The energy involved in chemical reactions

A) always appears as heat.
B) always appears as light.
C) always appears as electricity.
D) can take many forms.

Question 28

For the reaction of HCl and NaOH,which of the following type of chemicals will appear in the net equation?

A) weak acid
B) weak base
C) salt
D) water

Question 29

How many grams of N₂ are required to completely react with 3.03 grams of H₂ for the following balanced chemical equation? N₂ + 3H₂ $\rarr$ 2NH₃

A) 1.00
B) 6.00
C) 14.0
D) 28.0

Question 30

In the reaction 2H₂O $\rarr$ 2H₂ + O₂,2.0 mol water will produce how many grams of O₂?

A) 16
B) 32
C) 36
D) 64

Question 31

Given the equation 2CO + O₂ $\rarr$ 2CO₂,how many grams of CO₂ form if 34.0 grams of CO are combined with excess oxygen?

A) 53.4
B) 21.6
C) 145
D) 107

Question 32

Which ions in the following reaction would be classified as spectator ions?
Zn + 2H⁺ + 2Cl $\rarr$ Zn²⁺ + 2Cl^- + H₂

A) Zn²⁺
B) H⁺
C) Cl^-
D) More than one response is correct.

Question 33

If 5 grams of CO and 5 grams of O₂ are combined according to the reaction,which is the limiting reagent? 2CO + O₂ $\rarr$ 2CO₂

A) CO₂
B) O₂
C) CO
D) CO and O₂

Question 34

Which ions will appear in the total ionic equation for the following reaction?

A)
and

B)
and

C)
,
,and H⁺
D)
,
,
,and

Question 35

What is the reducing agent in the following reaction?
4HCl + MnO₂ $\rarr$ Cl₂ + 2H₂O + MnCl₂

A) HCl
B) Cl₂
C) MnO₂
D) MnCl₂

Question 36

In the reaction 2CH₄ + O₂ $\rarr$ 2CO + 4H₂,how many molecules of CO will be produced by the complete reaction of 1.60 grams of CH₄?

A) 12.0 * 10²³
B) 3.01 * 10²²
C) 6.02 *10²²
D) 2.00

Question 37

The Haber Process is a method for the production of ammonia,an important chemical intermediate.The reaction for this process is: N₂ + 3H₂ $\rarr$ 2NH₃.When the equation is correctly interpreted in terms of moles,how many moles of H₂ will react with one mole of N₂?

A) 1
B) 2
C) 3
D) 6

Question 38

Which of the following is a double replacement reaction?

A) CuO + H₂ $\rarr$ Cu + H₂O
B) HBr + KOH $\rarr$ H₂O + KBr
C) SO₂ + H₂O $\rarr$ H₂SO₃
D) 2HI $\rarr$ I₂ + H₂

Question 39

Which of the following is a combination reaction?

A) SO₂ + O₂ $\rarr$ 2SO₃
B) 2C₂H₂ + 5O₂ $\rarr$ 4CO₂ + 2H₂O
C) 2H₂O₂ $\rarr$ 2H₂O + O₂
D) AgNO₃ + NaCl $\rarr$ AgCl + NaNO₃

Question 40

Which of the following is a decomposition reaction?

A) SO₂ + O₂ $\rarr$ 2SO₃
B) 2C₂H₂ + 5O₂ $\rarr$ 4CO₂ + 2H₂O
C) 2H₂O₂ $\rarr$ 2H₂O + O₂
D) AgNO₃ + NaCl $\rarr$ AgCl + NaNO₃

Question 41

The following would represent what type of chemical reaction?

A) decomposition.
B) combination.
C) single replacement.
D) double replacement.

Question 42

A container is filled with 4.0 g H₂ and 5.0 g O₂.The mixture is ignited to produce water according to the following equation.How much water is produced?
2H₂ + O₂ $\rarr$ 2H₂O

A) 4.0 g
B) 5.0 g
C) 5.6 g
D) 9.0 g

Question 43

Automotive car batteries rely on the reaction shown below.Identify the spectator ion(s).
PbO₂(s)+ 4 H⁺(aq)+ 2 SO₄^2-(aq)+ Pb(s) $\rarr$ 2 PbSO₄(s)+ 2 H₂O(l)

A) SO₄^2-
B) H⁺
C) H⁺ and SO₄^2-
D) There are no spectator ions.

Question 44

Which of the following types of chemical reaction classes always involve oxidation?

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

Question 45

When nitrogen (N₂)reacts with sodium (Na),sodium nitride (Na₃N)is formed.The balanced equation for the reaction would be:

A)

B)

C)

D)

Question 46

A percentage yield greater than 100% has been reported in a scientific paper you are assigned to read.What would be a reasonable explanation for this?

A) A lack of training of the professor who published the study.
B) The product was measured more than once.
C) Small measurement errors could have caused this to occur.
D) It must be a typographical error since yields can't exceed 100%.

Question 47

Which of the following conversion factors would allow one to calculate the amount of PbI₂ produced from a given amount of NaI in the following unbalanced reaction?
Pb(NO₃)₂ + Nal $\rarr$ Pbl₂ + NaNO₃

A)

B)

C)

D)

Question 48

Consider the following chemical equation.Which substance is oxidized?
BaCl₂ (aq)+ H₂SO₄ (aq) $\rarr$ BaSO₄ (s)+ 2HCl (aq)

A) Ba²⁺
B) Cl^- and H⁺
C) SO₄^2-
D) none of them

Question 49

Tests are to be conducted on new anti-cancer drug and you are to prepare a fresh supply for the human subject studies.You discover that you were able to produce 1.345 g of this substance although it was theoretically possible to make 1.433 g.What was the percent yield for this synthesis?

A) 93.859 %
B) 93.86 %
C) 94 %
D) 0.9386 %

Question 50

What is the assigned oxidation number for molybdenum in aluminum molybdate,Al₂(MoO₄)₃?

A) +2
B) +3
C) +6
D) +7

Question 51

A percentage yield less than 100% is often obtained in a reaction.What is(are)the reason for obtaining less than theoretically predicted?

A) Side reactions occurred
B) poor laboratory technique
C) reaction did not go to completion
D) all of the choices

Question 52

Which is not a meaning of oxidation?

A) to gain electrons
B) to lose hydrogen
C) to combine with oxygen
D) to lose electrons

Question 53

What are coefficients needed to balance the following reaction?
2 CH₄ + ____ O₂ $\rarr$ ____ CO₂ + ____ H₂O

A) 8,2,4
B) 4,1,2
C) 4,2,4
D) none of these

Question 54

When the following equation is balanced,how many oxygen atoms are present on the reactant side of the equation? C₂H₆ + O₂ $\rarr$ CO₂ + H₂O

A) 14
B) 7
C) 3
D) 20

Question 55

According to the law of conservation of matter,which of the following may NEVER occur as a result of a chemical reaction?

A) creation of new chemical species.
B) reaction of starting materials.
C) rearranged to form new substances.
D) reduction in total mass.

Question 56

The modern definition of oxidation is a process

A) involving a reaction with oxygen.
B) in which hydrogen is gained.
C) in which electrons are gained.
D) none of the choices.

Question 57

Suppose 2.43 g of magnesium is reacted with 3.20 g of oxygen: 2Mg + O₂ $\rarr$ 2MgO.How many grams of MgO will be produced?

A) 5.63
B) 1.27
C) 8.06
D) 4.03

Question 58

The reaction 2KBr + F₂ $\rarr$ 2KF + Br₂ is an example of a _____ reaction.

A) spectator
B) metaphysical
C) single replacement
D) double replacement

Question 59

Tincture of iodine is an antiseptic.Which of the following is another antiseptic?

A) 5% sodium hypochlorite
B) 3% hydrogen peroxide
C) ozone
D) All are antiseptics

Question 60

The reaction below would be considered _____ .
CaCO₃ + heat $\rarr$ CaO + CO₂

A) an endothermic combination.
B) an exothermic combination.
C) an endothermic decomposition.
D) an exothermic decomposition.

Question 61

The reaction AgNO₃ + HCl $\rarr$ AgCl + HNO₃ is a redox reaction.

Question 62

All redox reactions are exothermic reactions.

Question 63

The oxidation number of iodine in HIO₄ is +6.

Question 64

The net ionic equation for the reaction H₂SO₄ + NaOH $\rarr$ Na₂SO₄ + H₂O is
H⁺ + OH $\rarr$ H₂O.

Question 65

Which of the following phrases can be used to describe the process of reduction?

A) to gain oxygen
B) to combine with hydrogen
C) to gain electrons
D) to decrease in oxidation number

Question 66

The reducing agent is the substance that is reduced in the reaction.

Question 67

The reaction Ca + Cl₂ $\rarr$ CaCl₂ is a redox reaction.

Question 68

In an exothermic reaction,heat is liberated to the surroundings.

Question 69

The reaction Mg + 3N₂ $\rarr$ Mg₃N₂ is correctly balanced as written.

Question 70

Redox reactions may also be a decomposition reaction.

Question 71

Some redox reactions involve only oxidation without any reduction.

Question 72

A net ionic equation may include one or more spectator ions.

Question 73

In the reaction Zn + Cu(NO₃)₂ $\rarr$ Cu + Zn(NO₃),the Zn is reduced.

Question 74

Air bags serve an important role in providing driver and front-seat passenger protection in the event of an automobile accident.They rely on several chemical reactions.Which of the following chemicals is responsible for N₂ production?

A) sodium azide
B) potassium nitrate
C) silicon dioxide
D) more than one answer is correct.

Question 75

The reactions NaOH + HCl $\rarr$ H₂O + NaCl and Ca(OH)₂ + 2HBr $\rarr$ 2H₂O + CaBr₂ have the same net ionic equation.

Question 76

In the reaction CuCl₂ + Fe $\rarr$ Cu + FeCl₂ the CuCl₂ is the oxidizing agent.

Question 77

Lycopene,a phytonutrient,has several potential health benefits,including protection against prostate,cervical and pancreatic cancer.Which of the following is a good source of this substance?

A) spinach
B) broccoli
C) strawberries
D) tomatoes

Question 78

Products are always on the right side of a chemical equation.

Question 79

Most reactions give a percent yield of almost 100%.

Question 80

In ionic compounds,metals have a positive oxidation number.