Deck 6: Chemical Reactions

Question 1

An aqueous solution of sodium nitrate (NaNO₃) is used in a reaction. The following should be used in the chemical equation for the reaction.
NaNO₃(l)

Answer 1

False

Question 2

Overall the reactions that occur during respiration can be classified as combustion reactions.

Answer 2

True

Question 3

During the carbon cycle plants produce the oxygen that is consumed by animals.

Answer 3

True

Question 4

Based on the following energy diagram, the activation energy for the reaction represented is approximately 40 kcal.

Question 5

When magnesium reacts with nitrogen, the reaction container becomes very hot. The ΔH for this reaction will have a positive sign.

Question 6

When you perspire, your body is cooled because the evaporation of moisture from you skin is an exothermic process.

Question 7

Photosynthesis and respiration are linked to each other in the nitrogen cycle.

Question 8

The following represents a typical energy diagram. The reaction represented by this energy diagram is endothermic.

Question 9

The combustion of glucose per gram produces more energy than the combustion of an equal mass of triolein (a fat).

Question 10

One Hawaiian sweet roll contains:
2.5 g fat
18 g carbohydrate
4.0 g protein
The total energy content of four rolls (to two significant figures) is 440 Calories.

Question 11

Consider the following image representing an equilibrium mixture. The black spheres represent the reactant and the gray spheres the product. If this reaction was started with only reactants, at equilibrium about 67% of the reactant was converted to product.

Question 12

The following reaction could be classified as a combustion reaction.
2Al₂O₃ (s) → 4Al(s) + 3O₂(g)

Question 13

Decreasing the temperature will decrease the number of collisions that result in product formation.

Question 14

Based on the following energy diagram, the heat of reaction for the reaction represented is approximately 20 kcal.

Question 15

The process that converts the energy stored in molecules to a form usable by an animal is respiration.

Question 16

Reactions that have a low energy of activation tend to proceed at a faster rate.

Question 17

The following represents a balanced chemical equation.
Al(NO₃)₃(aq) + Na ₃PO₄ (aq) → AlPO₄(s) + 3NaNO₃(aq)

Question 18

Consider the following image representing an equilibrium mixture. The black spheres represent the reactant and the gray spheres the product. This reaction was started with only reactants present. If the reaction had been started with only product present, the equilibrium mixture would contain 4 gray spheres and 8 black spheres.

Question 19

Consider the following reaction. The mass relationship between sodium (Na) and oxygen (O₂) is:

Question 20

Consider the following image.
This is a representation of a chemical reaction.

Question 21

The Haber Process is a method for the production of ammonia, an important chemical intermediate. The reaction for this process is:
N₂ + 3H₂ → 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 22

Which of the following most closely defines the term "reaction rate"?

A)the temperature needed to initiate a reaction
B)the position of a reaction at equilibrium
C)the speed of a reaction
D)the activation energy in the presence of a catalyst

Question 23

According to the law of mass conservation, 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 24

Consider the following reaction: This reaction:

A)is endothermic.
B)has a negative ΔH.
C)makes the surroundings warmer.
D)converts chemical energy into thermal energy.

Question 25

When the equation below is properly balanced, what coefficient is of KClO₃?
KClO₃ → KCl + O₂

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

Question 26

Consider the following reaction.
NaOH(aq) + H₂SO₄(aq) → Na₂SO₄(aq) + H₂O(l)
Which of the following represents the correct mass relationships, respectively, across the balanced equation?

A)40.00 g NaOH, 98.08 g H₂SO₄, 142.04 g Na₂SO₄, 18.02 g H₂O
B)40.00 g NaOH, 40.04 g H₂SO₄, 142.04 g Na₂SO₄, 9.010 g H₂O
C)80.00 g NaOH, 98.08 g H₂SO₄, 142.04 g Na₂SO₄, 36.04 g H₂O
D)80.00 g NaOH, 98.08 g H₂SO₄, 142.04 g Na₂SO₄, 18.02 g H₂O

Question 27

Which of the following will influence all reaction rates?

A)the presence of catalysts
B)the temperature of reactants
C)the concentration of reactants
D)More than one response is correct.

Question 28

Which of the following reactions is correctly balanced?

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

Question 29

When you inhale (breathe in), oxygen is entering your respiratory system and when you exhale (breathe out), carbon dioxide is leaving your respiratory system.

Question 30

If the reaction given below occurs and pure A and B were mixed, which of the following would take place as equilibrium was established?
A + B C

A)The concentration of C would increase for a time, then remain constant.
B)The concentration of A would increase for a time, then decrease.
C)The concentration of B would increase for a time, then remain constant.
D)Both a and c will occur.

Question 31

In the equation for an exothermic reaction, the word "energy" appears

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

Question 32

A block of iron forming a pool of the liquid metal is correctly classified as

A)a chemical change.
B)a physical change.
C)both a chemical and a physical change.
D)neither a chemical nor a physical change.

Question 33

Which of the following is a physical property of matter?

A)does not burn.
B)produces a gas when placed in an acid
C)freezes at −10°F
D)the surface of a solid turns black in air

Question 34

Consider the following reaction.
NaOH(aq) + HCl(aq) → NaCl(aq) + H₂O(l)
If 25.0 mL of a 0.100 M solution of NaOH reacted with excess HCl, how many moles of NaCl could form?

A)25.0 mol
B)0.100 mol
C)0.00250 mol
D)2.50 mol

Question 35

How many moles of N₂ are required to completely react with 3.53 grams of H₂ for the following balanced chemical equation?
N₂ + 3H₂ → 2NH₃

A)16.4 mol
B)1.17 mol
C)0.584 mol
D)5.25 mol

Question 36

When natural gas (predominantly methane, CH₄) burns in air. The following reaction occurs. How much energy is involved in the combustion of 13.0 g of methane?

A) kcal
B)16.4 kcal
C)173 kcal
D)0.979 kcal

Question 37

Consider the following generic reaction.
2 A(s) + 3 B(l) → C(g)
If 58.0 g of A reacted completely with B to produce 100.8 g of C, what mass of B reacted?

A)58.0 g
B)174 g
C)87.0 g
D)42.8 g
E)The mass cannot be determined without knowing the identities of reactants and products.

Question 38

Which of the following statements is not true about the reaction as written below?

A)Hydrogen is a reactant.
B)C₂H₄ is a reactant.
C)The reaction is balanced.
D)The reaction is at equilibrium.

Question 39

Ethanol is produced industrially by the acid catalyzed reaction of ethylene with water. The balanced equation for this reaction is:
C₂H₄(g) + H₂O(g) → C₂H₅OH(l)
If water is present in excess, how many grams of ethanol can be produced from 5.75 g of ethylene?

A)265 g
B)0.205 g
C)3.50 g
D)9.44 g

Question 40

The reactants in a chemical reaction are analogous to which of the following?

A)a baked cake
B)the flour, eggs, chocolate used to bake a cake
C)the cake pan.
D)the heat of the oven

Question 41

The following would be classified as a _______________________reaction.

Question 42

Which of the following symbols is used to denote a reversible reaction?

A)→
B)←
C)
D)↔

Question 43

If a reaction occurs very rapidly, even at a relatively low temperature, which of the following is probably true?

A)The reaction is endothermic.
B)The reaction is exothermic.
C)The reaction has a low activation energy.
D)The reaction is at equilibrium.

Question 44

Consider the following reaction. How many grams of sucrose would produce 2546 kcal?

A)649.4 g
B)1342 g
C)180.4 g
D)1.897 g

Question 45

Which of the following is the best definition of a catalyst?

A)A catalyst is a material that speeds up the rate of a chemical reaction.
B)A catalyst is a material that speeds up the rate of a chemical reaction without participating in the reaction.
C)A catalyst is a material that speeds up the rate of a chemical reaction without being consumed during the reaction.
D)All of the above are equally good definitions.

Question 46

What is the name of a branch on the principal carbon chain that contains three carbon atoms?

A)pentyl
B)propyl
C)ethyl
D)methyl

Question 47

Consider the following energy diagram showing a reaction with and without a catalyst..
Fill in the blank with the appropriate letter (A,B,C,etc.).
The activation energy of the catalyzed reaction is represented by_____________________.

Question 48

Copper reacts with nitric acid as given in the following reaction. Predict the effect of the given change on the rate of the reaction by filling in the blank with one of the following terms.
increase
decrease
no effect
The concentration of the nitric acid is increased. ______________________

Question 49

Consider the following energy diagram showing a reaction with and without a catalyst..
Fill in the blank with the appropriate letter (A,B,C,etc.).
The heat of reaction would be represented by _____________________.

Question 50

Consider a sample of water in a closed container. When the reaction H₂O(l) H₂O(g)
Has reached equilibrium, what can we say about any specific water molecule?

A)If it was present in the liquid it will always remain in the liquid.
B)If it was present in the gas it will always remain in the gas.
C)It will sometimes be in the liquid phase and sometimes in the gas phase.
D)Both a and b are true.

Question 51

When the following equation is balanced using integers, the number of atoms of carbon represented in reactants or products is:

A)8 atoms.
B)4 atoms
C)6 atoms.
D)10 atoms.

Question 52

If the 'Nutrition Facts' on a food label contains Total Fat 5.0 g, Total Carbohydrate 35 g, and Total Protein 7.0 g, how many Total kcal would be needed for the average healthy person to burn this food item?

A)1.8 × 10² kcal
B)2.1 × 10² kcal
C)4.2 × 10² kcal
D)4.0 × 10² kcal

Question 53

Complete the following sentence using the terms provided below.
nutritive value
carbohydrate
protein
fat
Calorie
kilocalorie
energy content
_______________________refers to the characteristic amount of heat produced when a nutrient is burned.

Question 54

Copper reacts with nitric acid as given in the following reaction. Predict the effect of the given change on the rate of the reaction by filling in the blank with one of the following terms.
increase
decrease
no effect
A catalyst is added to the reaction mixture. ____________________

Question 55

Consider the following energy diagram showing a reaction with and without a catalyst..
Fill in the blank with the appropriate letter (A,B,C,etc.).
The lowering of the activation energy by the catalyst is represented by__________________.

Question 56

Which of the following the appropriate ending for the name of many aromatic compounds?

A)benzene
B)ane
C)yne
D)ene

Question 57

Copper reacts with nitric acid as given in the following reaction. Predict the effect of the given change on the rate of the reaction by filling in the blank with one of the following terms.
increase
decrease
no effect
The copper metal is ground into a very fine powder. ______________________

Question 58

Per gram ________________________ produces the largest amount of energy when burned.

Question 59

Copper reacts with nitric acid as given in the following reaction. Predict the effect of the given change on the rate of the reaction by filling in the blank with one of the following terms.
increase
decrease
no effect
The temperature of the reaction is decreased. _____________________

Question 60

Many molecular collisions do not result in chemical reaction. Which of the following explains this observation?

A)The colliding molecules may not be the correct chemicals.
B)The colliding molecules do not have sufficient energy.
C)The colliding molecules do not have the correct orientations.
D)All of the above are potential factors.

Question 61

Complete each of the following sentences using one of the terms listed below.
physical change
chemical change
reactant
product
coefficient
physical state
Consider the image below. In the balanced chemical equation hydrogen would be written as H₂(g) where the parenthetical designation represents its________________.

Question 62

Complete each of the following sentences using one of the terms listed below.
physical change
chemical change
reactant
product
coefficient
physical state
The image below represents a________________.

Question 63

When 15.0 g of sucrose is burned during metabolism in the body according to the following equation, what mass in grams of oxygen is needed?

Question 64

Complete each of the following sentences using one of the terms listed below.
physical change
chemical change
reactant
product
coefficient
physical state
Consider the image below. If the balanced equation for this reaction were written oxygen would have a ___________ of 1.

Question 65

When a nickel-cadmium battery is recharged, the following reaction occurs. What mass in grams of nickel(II) hydroxide is consumed if 2.40 g of Cd is produced?

Question 66

Draw the energy diagram for the following reaction which represents the burning of the amino acid alanine. Indicate on the diagram the activation energy and the heat of reaction.

Question 67

Complete each of the following sentences using one of the terms listed below.
physical change
chemical change
reactant
product
coefficient
physical state
The image below represents a________________.

Question 68

Complete each of the following sentences using one of the terms listed below.
physical change
chemical change
reactant
product
coefficient
physical state
In the image below hydrogen sulfide represents the________________.