Deck 9: Chemistry of Fire and Heat

Question 1

What did the prosecution claim Kenny Richey had stolen to start a fire?

A)Paint thinner
B)Gasoline and paint thinner
C)Kerosene and paint thinner
D)Lighter fluid

Answer 1

B

Question 2

Where on Kenny Richey were traces of gasoline and paint thinner found?

A)In his hair
B)On his clothing
C)On his hands
D)Nowhere

Answer 2

D

Question 3

Why did the defense maintain that Kenny Richey probably did not start the fire of which he was accused?

A)He had no matches on him to start a fire.
B)He hadn't taken the gasoline or paint thinner.
C)He had no gasoline or paint thinner residue on him, and had a broken hand, making it hard to handle and spread such liquids.
D)He had no past arrests for arson.

Answer 3

C

Question 4

Even though no gasoline or paint thinner traces had been found on Kenny Richey, why did the prosecutor's office go forward with the case?

A)He had been involved in several arsons in the past.
B)He had an established record of assault and petty theft.
C)He had bragged to friends that evening that he was going to commit this arson.
D)None of the above; rather, they didn't go forward with the case.

Question 5

What ingredients are needed for a fire?

A)A fuel source
B)Oxygen gas
C)Heat
D)All of the above

Question 6

What is heat?

A)A mass form transferred from object to object upon contact
B)An energy form transferred from object to object upon contact
C)A mass-energy transfer when hot and cold objects come into contact
D)An energy form transferred from hot to cold objects when they come in contact with each other

Question 7

What is the condition called when two or more objects touch and reach the same temperature?

A)Static equilibrium
B)Thermal equilibrium
C)Dynamic equilibrium
D)Isotonic equilibrium

Question 8

What is the SI unit of heat energy?

A)The joule
B)The calorie
C)The coulomb
D)The ºC

Question 9

How is temperature best defined?

A)The amount of joules in a system
B)The calorie content of the particles of a system
C)The measurement of the average kinetic energy of the particles of a system
D)The equilibrium of the average kinetic energy of the particles in an open system

Question 10

How does water interrupt the "fire triangle"?

A)It removes the ignition sources.
B)It takes oxygen away from the fire.
C)It quenches the fuel in the system.
D)It removes heat from the system.

Question 11

Fire must have an oxygen source to continue combustion.

Question 12

In an indoor fire in a poorly ventilated room, what can the room fill with?

A)Flammable materials created through the total combustion of other materials
B)Flames
C)Soot particles
D)Flammable compounds created through incomplete combustion

Question 13

What is another term for a smoke explosion?

A)A limiting thrust
B)A vapor blow
C)A backdraft
D)A fire triangle

Question 14

Why are some wood-based smokes white and others black?

A)It depends on the completeness of the burning.
B)It depends upon the water content of the wood being burned.
C)It depends on the color of the wood being burned.
D)It depends on the size of the wood being burned.

Question 15

The complete combustion of wood has carbon dioxide as one of its products.

Question 16

Balancing a combustion equation should be done in what elemental order?

A)C-H-O
B)H-O-C
C)O-H-C
D)C-O-H

Question 17

Which is the balanced equation for the complete combustion of ethanol (C₂H₅OH) in oxygen gas?

A)C₂H₅OH + 7 O₂ → 2 CO₂ + 3 H₂O
B)2 C₂H₅OH + 7 O₂ → 4 CO₂ + 6 H₂O
C)2 C₂H₅OH + 7/2 O₂ → 4 CO₂ + 6 H₂O
D)C₂H₅OH + 7 O₂ → 4 CO₂ + 6 H₂O

Question 18

The balanced equation for the complete combustion of methanol (CH₃OH) in oxygen gas is what?

A)2 CH₃OH + O₂ → 2 CO₂ + 4 H₂O
B)2 CH₃OH + 3 O₂ → 2 CO₂ + 4 H₂O
C)CH₃OH + 3 O₂ → 2 CO₂ + 2 H₂O
D)CH₃OH + 3 O₂ → CO₂ + 4 H₂O

Question 19

What is the proper, balanced equation for the complete combustion of propanol (C₃H₇OH) in oxygen gas?

A)2 C₃H₇OH + 9 O₂ → 3 CO₂ + 4 H₂O
B)C₃H₇OH + 9 O₂ → 6 CO₂ + 8 H₂O
C)2 C₃H₇OH + 9 O₂ → 6 CO₂ + 8 H₂O
D)C₃H₇OH + 9 O₂ → 3 CO₂ + 4 H₂O

Question 20

The complete combustion of methane gas (CH₄) in oxygen gas is what?

A)CH₄ + 2 O₂ → CO₂ + 2 H₂O
B)2 CH₄ + 2 O₂ → 2 CO₂ + 2 H₂O
C)CH₄ + 2 O₂ → 2 CO₂ + 2 H₂O
D)2 CH₄ + 2 O₂ → CO₂ + 2 H₂O

Question 21

How is the complete combustion of ethanol (C₂H₅OH) in oxygen gas represented?

A)2 C₂H₅OH + 2 O₂ → 4 CO₂ + 6 H₂O
B)2 C₂H₅OH + 7 O₂ → 4 CO₂ + 6 H₂O
C)C₂H₅OH + 7 O₂ → 4 CO₂ + 6 H₂O
D)C₂H₅OH + 4 O₂ → 4 CO₂ + 6 H₂O

Question 22

Which is the balanced equation for the complete combustion of ethane gas (C₂H₆) in oxygen gas?

A)2 C₂H₆ + 7 O₂ → 4 CO₂ + 6 H₂O
B)2 C₂H₆ + 4 O₂ → 4 CO₂ + 6 H₂O
C)2 C₂H₆ + 7 O₂ → 4 CO₂ + 3 H₂O
D)2 C₂H₆ + 7 O₂ → 2 CO₂ + 6 H₂O

Question 23

The total combustion of sugar, C₆H₁₂O₆, in oxygen is which of the following?

A)C₆H₁₂O₆ + O₂ → 6 CO₂ + H₂O
B)2 C₆H₁₂O₆ + 12 O₂ → 12 CO₂ + 6 H₂O
C)2 C₆H₁₂O₆ + 6 O₂ → 6 CO₂ + 6 H₂O
D)C₆H₁₂O₆ + 6 O₂ → 6 CO₂ + 6 H₂O

Question 24

All combustion reactions involve what reactants?

A)Metals and oxygen
B)Organic compounds and oxygen
C)Organic compounds and ignitors
D)Oxygen and species of wood

Question 25

What products occur under ideal conditions in any combustion reaction?

A)Carbon oxides
B)Carbon dioxide
C)Carbon dioxide and water
D)Carbon oxides and water

Question 26

In KBr, what is the oxidation number of potassium?

A)-1
B)0
C)+1
D)+2

Question 27

What is the oxidation number of oxygen in the reactants of the following reaction:
CH₄ + 2 O₂ → CO₂ + 2 H₂O?

A)-1
B)-2
C)2
D)0

Question 28

What is the oxidation number of oxygen in the compound MgO?

A)+2
B)0
C)-1
D)-2

Question 29

In the compound H₂SO₄, what is the oxidation number of S?

A)0
B)+6
C)-2
D)-4

Question 30

What is the oxidation number of carbon in the products of this reaction 2 C₂H₆ + 7 O₂ → 4 CO₂ + 6 H₂O?

A)+4
B)0
C)-4
D)There is not enough information to tell.

Question 31

The oxidation number of hydrogen in both sides of the following reaction, 2 C₂H₆ + 7 O₂ → 4 CO₂ + 6 H₂O, are the same. What is that number?

A)0
B)+1
C)-1
D)There is not enough information to tell.

Question 32

In water, what is the oxidation state of oxygen?

A)-2
B)+1
C)0
D)+2

Question 33

To what does the term oxidation refer?

A)The gain of electrons
B)The movement of electrons
C)The loss of electrons
D)The reduction of electrons

Question 34

What is the oxidation number of S in the compound H₂S?

A)0
B)-1
C)-2
D)+2

Question 35

How does the oxidation number of Ca change in the reaction: 2 Ca + O₂ → 2 CaO?

A)It goes from 0 to +2.
B)It goes from 0 to -2.
C)It remains 0 in the reactants and products.
D)There is not enough information to tell.

Question 36

How does the oxidation number of C change in the following reaction: CH₄ + 2 O₂ → CO₂ + 2 H₂O?

A)There is not enough information to tell.
B)It does not change.
C)From -2 to +2
D)From -4 to +4

Question 37

How does the oxidation number of H change in the following reaction: CH₄ + 2 O₂ → CO₂ + 2 H₂O?

A)It goes from -1 to +1.
B)It goes from -2 to +2.
C)It does not change.
D)There is not enough information to tell.

Question 38

In the following reaction, how does the oxidation number of O change: CH₄ + 2 O₂ → CO₂ + 2 H₂O?

A)It goes from 0 to +2.
B)It goes from 0 to -2.
C)It does not change.
D)There is not enough information to tell.

Question 39

What is the oxidation number of Cl in KClO₄?

A)-1
B)+7
C)0
D)-4

Question 40

What happens to elemental metals when they react in a redox reaction?

A)They typically lose electrons.
B)They typically gain electrons.
C)They neither gain nor lose electrons.
D)There is not enough information in the question to tell.

Question 41

In what form does oxygen not have an oxidation number of -2?

A)In aqueous solution
B)Under basic conditions
C)Under acidic conditions
D)As a free element

Question 42

What happens to the number of electrons in an element when it is oxidized?

A)It increases.
B)It decreases.
C)It stays the same.
D)It increases only in acidic solution.

Question 43

What typically happens to non-metal free elements (like oxygen or nitrogen) when they react in a redox reaction?

A)They are oxidized.
B)They are reduced.
C)They are neither oxidized nor reduced.
D)They combust.

Question 44

An atom that has gone from an oxidation state of -2 to -1 in a reaction has undergone what process?

A)It has oxidized.
B)It has reduced.
C)It has become more acidic.
D)It has become more basic.

Question 45

The reduction of any atom ends in an oxidation state of zero.

Question 46

In an unbalanced chemical equation in which the following occurs: Fe₂O₃ → FeO, what has happened to the iron in the reaction?

A)It has been oxidized.
B)It has been reduced.
C)It has become acidic.
D)It has become basic.

Question 47

What is pyrolysis?

A)The decomposition of a solid to form combustible, gaseous compounds.
B)The decomposition of a gas to form combustible, gaseous compounds.
C)The decomposition of a solid to form non-combustible materials.
D)The decomposition of a liquid to form non-combustible materials.

Question 48

Why is heat needed to initiate combustion?

A)Energy is needed to start the fuel-oxygen reaction.
B)Liquids and solids need to be converted to vapors.
C)Neither of the above.
D)Both of the above.

Question 49

Vaporization of a liquid fuel to a gas that can combust is what category of reaction?

A)Hypothermic
B)Exothermic
C)Endothermic
D)Not enough information to tell

Question 50

What do all exothermic reactions produce?

A)Heat
B)Light
C)Smoke
D)Fumes

Question 51

In an exothermic reaction energy diagram, what is the relationship between the reactants' and the products' energies?

A)The products are higher than the reactants.
B)The reactants are higher than the products.
C)Both reactants and products are the same energy.
D)The reactants are always higher than the activation energy.

Question 52

Endothermic processes always give off heat at the completion of the reaction.

Question 53

How does a flashover spread?

A)Across the ceiling of a room where a fire exists
B)Through the ventilation system of a house
C)Across the floor of a room where a fire exists
D)Through other combustible material in a room where a fire exists

Question 54

What term is used to denote the energy required to start a chemical reaction?

A)The start-up energy
B)The activation energy
C)The threshold energy
D)The combustion energy

Question 55

What occurs in a chemical reaction when the activation energy is not achieved?

A)The reactants explode.
B)The reaction can only proceed slowly.
C)The reaction does not proceed.
D)The reactants degrade.

Question 56

When a chemical cold pack is used to treat an athlete's injury, what functions as the heat source?

A)The packaging in which the chemicals are housed
B)The components of the cold pack itself
C)The atmosphere
D)The part of the athlete's body where the pack is placed

Question 57

All exothermic reactions have a final energy of their products that is lower than the energy of the reactants.

Question 58

A material can reach a heat at which it can combust without a spark or flame. What term describes this?

A)The boiling point
B)The melt-boil temperature
C)Fahrenheit 451
D)The auto-ignition temperature

Question 59

What physical change occurs at the melting point of a material?

A)Liquid becomes gas.
B)Solid becomes liquid.
C)Liquid becomes solid.
D)Solid becomes gas.

Question 60

How is specific heat defined?

A)The amount of heat needed to raise 1 mole of material 1ºF
B)The amount of heat needed to raise 1 g of material 1ºF
C)The amount of heat needed to raise 1 mole of material 1ºC
D)The amount of heat needed to raise 1 g of material 1ºC

Question 61

What do the specific heats of materials like copper, aluminum, and concrete all have in common?

A)They span from low to high.
B)They are all very high.
C)They are all very low.
D)They have nothing in common.

Question 62

How much higher is the specific heat of water than of the metals listed in Table 1?

A)At least four times
B)At least eight times
C)At least ten times
D)It is not higher at all.

Question 63

What can the temperature of a typical building fire reach?

A)1300 K
B)1300ºF
C)1300ºC
D)None of the above

Question 64

What intermolecular forces account for the much higher specific heat capacity of water than of metals?

A)Permanent dipoles
B)Hydrogen bonding
C)Both of the above
D)None of the above

Question 65

In a temperature vs. heat diagram, such as Figure 5, what does a plateau represent?

A)An equilibrium adjustment
B)The loss of heat
C)The addition of heat
D)A phase change

Question 66

The amount of energy required to convert a liquid to a gas is known as what?

A)The heat of conversion
B)The heat of vaporization
C)The heat of gasification
D)The heat of nebulization

Question 67

What is the heat of fusion?

A)The heat needed to melt a solid completely.
B)The heat required to join two metals.
C)The heat needed to separate two metals.
D)The heat required to melt a fuse.

Question 68

According to a phase graph such as that in Worked Example 9, what happens to the temperature of water from the time the first drop of liquid forms from ice to the time the last bit of ice melts?

A)It continues to rise slowly.
B)It stays the same.
C)It actually decreases slowly.
D)There is not enough information on the graph to tell.

Question 69

Why might the specific heat capacity of water be so much higher than the metals listed in Table 9.1?

A)Because water has a heat of vaporization and metals do not
B)Because the metals do not have mineral structures
C)Because water is a liquid
D)Because water possesses a hydrogen bonding network

Question 70

Which of the following materials found in a fire give clues to the temperature of the fire?

A)Water and plastics from household materials
B)Copper from wiring
C)Steel from furniture parts
D)Both B and C

Question 71

How much heat is evolved when a 35.0 g sample of copper increases from 25.0ºC to 35.5ºC?

A)472.0 J
B)139.7 J
C)262.5 J
D)13.3 J

Question 72

What amount of heat is evolved when a piece of concrete rises in temperature from 27ºC to 50ºC?

A)40.0 J
B)21.6 J
C)18.4 J
D)Not enough information to tell

Question 73

When a 213.0 g sample of aluminum is raised in temperature from 22.0ºC to 95.0ºC, what amount of heat is produced?

A)13,994 J
B)18,211 J
C)4,217 J
D)15,549 J

Question 74

When a 500.0 g sample of silica glass changes temperature from 23.0°C to 50.0°C, what amount of heat is involved?

A)18,750 J
B)10,125 J
C)8,625 J
D)25,000 J

Question 75

What does the inner chamber of a calorimeter contain?

A)An ignition source and an oxygen environment
B)The sample and an ignition source
C)The sample, an ignition source, and an oxygen environment
D)The sample and an oxygen environment

Question 76

What does a cone heater measure while heating a sample?

A)The oxygen in the air above the burning object
B)The oxygen in the burning sample
C)The amount of sample combusted
D)The amount of sample mixed with oxygen

Question 77

How many kJ of heat are produced for each gram of oxygen consumed in a combustion?

A)4.184 kJ
B)31.0 kJ
C)13.0 kJ
D)0.905 kJ

Question 78

In a bomb calorimeter, how much of the sample being tested is consumed?

A)1 mole of the sample
B)1 g of the sample
C)
$1 / 2$ of the sample
D)All of the sample

Question 79

What requirements must be met for combustion in a bomb calorimeter?

A)Activation energy must be met
B)Energy for a phase change and pyrolysis must be met
C)Neither a or b
D)Both a and b

Question 80

The amount of energy released by a chemical process is always equal to that absorbed by the system or surroundings. This is a statement of what phenomenon?

A)The first law of exothermic reactivity
B)The law of conservation of moles
C)The first law of molecular motion
D)The law of conservation of energy