1.
True
2.
Combustion releases chemical energy in the form of thermal energy and light.
3.
In addition to releasing chemical energy, the combustion of hydrocarbons also produces by-products including carbon dioxide, carbon monoxide, and water.
4.
Greenhouse gases are any gases in the atmosphere (such as water vapour, carbon dioxide, and methane) that absorb lower-energy infrared radiation.
5.
a
6.
a
7.
Air pollution is chemicals released into the atmosphere that have the potential to harm the health of humans and other living things.
8.
False. Hy drocarbons are comprised of two specific elements, carbon and hydrogen.
9.
Complete combustion is the ideal method for burning a hydrocarbon because complete combustion of a hydrocarbon releases the most energy from the hydrocarbon molecules. When burned in a complete manner, hydrocarbons will produce the hottest flames and the least soot.
10. Table 1 The Complete Combustion of Methane word equation methane + oxygen → carbon dioxide + water skeleton equation CH
4
+ O
2
(g) → CO
2
(g) + H
2
O(l) balanced chemical equation CH
4
+ 2 O
2
(g) → CO
2
(g) + 2 H
2
O(l)
11.
Table 2 Determine the Hydrocarbon
Equation for Reaction Hydrocarbon
2 C x
H y
+ 13 O
2
(g) → 8 CO
2
(g) + 10 H
2
O(l)
2 C x
H y
+ 7 O
2
(g) → 4 CO
2
(g) + 6 H
2
O(l)
C x
H y
+ 5 O
2
(g) → 3 CO
2
(g) + 4 H
2
O(l)
C
C
C
4
2
3
H
10
H
H
6
8
C x
H y
+ 11 O
2
(g) → 8 CO
2
(g) + 6 H
2
O(l) C
4
H
6
12.
(a) An acetylene torch being used in a confined space may not work because the oxygen supply may be limited. This is inhibiting the complete combustion of acetylene from the torch, lowering the temperature of the flame. As a result, the welder is unable to repair the pipe.
(b) To fix the pipe, the welder may have to add an oxygen source to the tip of the torch to fuel the combustion reaction. This would create the conditions for complete combustion of the fuel, increasing the temperature of the flame, and allow for the repair of the pipe.
13.
(a) The flames produced from the complete combustion of a hydrocarbon are blue, produce little soot, and are intensely hot.
(b) The flames produced from the incomplete combustion of a hydrocarbon are often yellow, sooty, and warm when compared with those produced during a complete combustion reaction.
14.
Incomplete combustion reactions often produce a wide range of by-products, including soot. Soot is represented in a chemical equation as C(s).
15.
(a) C
8
H
18
+ O
2
(g) → C(s) + H
2
O(l)
C
8
H
18
+ O
2
(g) → CO(g) + H
2
O(l)
(b)
2 C
(c)
2 C
2 C
8
H
18
+ 17 O
C
8
8
H
H
8
18
H
18
18
+9 O
+ O
2
+ 25 O
2
2
(g) → 16 C(s) + 18 H
2
(g) → 16 CO(g) + 18 H
(g) → CO
2
(g) + H
2
(g) → 16 CO
2
2
O(l)
2
(g) + 18 H
O(l)
O(l)
2
O(l)
Copyright © 2011 Nelson Education Ltd. Chapter 5: Chemical Processes 5-1

16.
Three of the most pressing issues associated with incomplete combustion are the following.
(1) Incomplete combustion creates inefficiency. An example is a car engine that does not burn gasoline efficiently. Incomplete combustion wastes resources and does not allow for optimization of energy use from the combustion process.
(2) Combustion produces soot that, if inhaled, can pose a significant health problem for humans and animals.
Soot released by energy plants creates pollution.
(3) Incomplete combustion results in the release of carbon monoxide. Often viewed as the silent killer, this compound can reduce oxygen supply to the body, resulting in the death of an individual.
1.
Answers may vary. Examples of products discovered by chance include three of the following: Teflon  ,
Scotchguard ™ , Super Glue  , or the element iodine.
2.
Five steps commonly used in the scientific research process are:
(1) Ask a question.
(2) Conduct background research.
(3) Construct a hypothesis.
(4) Test the hypothesis.
(5) Analyze the results obtained from testing the hypothesis.
3.
As a result of her work, Marie Curie died from a condition caused by exposure to radioactive materials. The damaging effects of ionizing radiation were not yet known.
4.
Table 1 Costs and Benefits of Chance Discoveries
Costs Benefits
Accidental discoveries occur because of an unknown or unanticipated reaction that occurs during a planned experiment.
Because the unintended outcomes were not anticipated, scientists conducting these experiments may not be aware of the harms of the new products created.
Chance discoveries can produce products that have numerous applications. These products may also enhance the quality of human life, generating new inventions or solutions to challenging problems. Further, these chance discoveries may provide valuable insight into the reactions that occur at the chemical level. All of these outcomes have benefits for human advancement and for improving scientific understanding of the world.
5.
Answers may vary. Sample answer: When a scientist discovers a new product by chance through the use of a planned experiment, this indicates that some unforeseen reaction has occurred. In handling the new product, the scientist must take every precaution to ensure safety in handling the material. Once safety issues have been addressed, the scientist should investigate the chemical structure of the new compound and its properties, to determine how the product might be used.
1.
Table 1 Properties of Metals and Non-Metals
Metals Non-metals
• shiny
• malleable
• good conductors of electricity
• dull
• brittle
• poor conductors of electricity
2.
False. An oxide is a compound of any element combined with oxygen.
3.
Table 2 The Oxidation of Iron word equation iron + oxygen → iron oxide skeleton equation Fe + O
2
(g) → Fe
2
O
3
(s) balanced chemical equation 4 Fe + 3 O
2
(g) → 2 Fe
2
O
3
(s)
Copyright © 2011 Nelson Education Ltd. Chapter 5: Chemical Processes 5-2

4.
(a) Acids produce hydrogen ions in solution.
(b) Acids produce solutions that conduct electricity, taste sour, turn blue litmus red, and neutralize bases.
(c) HCl(aq) → H
+
(aq) + Cl
–
(aq)
(d) Bases produce hydroxide ions in solution.
(e) Bases produce solutions that conduct electricity, taste bitter, turn red litmus blue, and neutralize acids.
(f) NaOH(s) → Na
+
(aq) + OH
–
(aq)
5.
(a) A solution has a higher degree of acidity because of the hydrogen ions that are present.
(b) Table 3 Acids and Bases
Solution Acid or Base vinegar acid detergent lemon juice bleach base acid base water neutral
6.
True
7.
Table 4 Acid or Base Product
Equation for Reaction Acid or Base
SO
2
+ H
2
O(l) →
Na
2
O + H
2
O(l) →
MgO + H
2
O(l) → acid base base
Cl
2
O
5
+ H
2
O(l) → acid
8.
(a) Rainwater from the atmosphere has a pH that is lower than 7.0, indicating that it is slightly acidic, because the water reacts with carbon dioxide in the air, producing carbonic acid. Carbonic acid rapidly decomposes, creating hydrogen ions that make the rainwater acidic.
(b) CO
2
(g) + H
H
2
CO
3
(aq) → H
2
O(l) → H
2
CO
+
(aq) + HCO
3
3
−
(aq)
(aq)
(c) d
9.
(a) True
(b) N
2
(g) + O
2
(g) → 2 NO
(c) 2 NO(g) + O
2
(g) → 2 NO
2
(g)
(d) 2 NO
2
(e) 2 NO
2
(g) + H
2
(g) → N
2
O(l) → HNO
3
(g) + 2 O
2
(g)
(aq) + HNO
2
(aq)
10.
Some of the effects of acid rain on plant, animal, and human life are as follows: Acid rain primarily impacts water resources. This can make it difficult for fish to thrive and for plants to get needed nutrition.
Plant and animal life can die as a result of an acidic water supply. Acid rain impacts drinking water for humans and also erodes the physical infrastructure developed in the environment. One example is the erosion of metal on cars when exposed to acid rain over the long term.
Copyright © 2011 Nelson Education Ltd. Chapter 5: Chemical Processes 5-3

1.
Table 1 Completing Equations for Neutralization Reactions
Reactants Products
HCl + NaOH → NaCl + H
2
O
H
2
SO
4
+ 2 NH
4
OH →
Ca(OH)
2
+ H
2
CO
3
→
HNO
3
+ KOH →
(NH
4
)
2
SO
4
+ 2 H
2
O
CaCO
3
+ 2 H
2
O
KNO
3
+ H
2
O
H
3
PO
4
+ 3 NaOH → Na
3
PO
4
+ 3H
2
O
2.
(a) Colour A is magenta (pink) and colour B is clear in Figure 1.
(b) The pH of the final solution is 7 if acid is added to the solution until the initial colour of the solution fades.
3.
(b)
(a) 2 HCl(aq) + CaCO
HCl(aq) + NaHCO
3
3
(s) → CaCl
(s) →
2
(aq) + H
NaCl(aq) + H
2
2
O(l) + CO
O(l) + CO
2
2
(g)
(g)
(c) Excess sodium ions have been linked to hypertension (high blood pressure) and strokes.
4.
Baking soda included as an ingredient in cookie recipes to make the cookies rise. Baking soda is a pure form of hydrogen carbonate. When it is mixed with an acid (such as fruit juice or buttermilk) in the baking process, a neutralization reaction occurs in which carbon dioxide is formed. The release of carbon dioxide causes the dough to rise. When the dough is heated, the carbon dioxide bubbles expand further, increasing the size of the dough.
5.
When a strong acid is used for neutralizing a base, excess hydrogen ions in solution may be generated, and the hydrogen ions can react with the containers in which the neutralizing reaction occurs. Additionally, because HCl is so reactive, some may be left in solution, so that you would need to neutralize the acid before disposing of the solution. Finally, reactions involving HCl can be highly exothermic, causing boiling and splattering of the material.
6.
Sodium hydrogen carbonate, NaHCO
3
is considered to be a unique neutralizing agent because it can neutralize both acids and bases, it is safe, and it is non-corrosive.
7.
(a) Sodium hydroxide is commonly used as a drain cleaner because blocks in drains are often caused by grease, which is acidic. Adding sodium hydroxide to the acidic grease neutralizes the grease, converting the fats into soap, which is only mildly basic and dissolves in water. Only relatively harmless chemicals are released into the water system. Also, when sodium hydroxide dissolves in water, a great deal of thermal energy is released, and this helps to melt the grease.
(b) In addition to containing sodium hydroxide, drain cleaners often also contain chemicals which increase the speed of the reaction. These chemicals are known as catalysts.
1.
A mineral is a naturally occurring solid that has a definite crystal structure and chemical composition.
2.
In order to access ores, mining companies can use two mining methods: surface mining and underground mining.
3.
Surface mining requires the removal of large quantities of material on the surface to reach the ores.
Returning the surface to its natural state following mining can be a difficult process and poses unique environnemental challenges.
4.
In the process known as flotation, ore collected from the group is crushed and mixed with water, air, and an ionic compound. The ionic compound breaks down into ions that are negative at one end and positive at the other. The negative end is hydrophilic and attracted to water, while the positive end is hydrophobic or repelled by water. The hydrophilic ends attach themselves to the ore, and the hydrophobic ends enter the air bubbles.
The air rises, pulling the ore to the top. The ore can then be skimmed off from the processing tank.
Copyright © 2011 Nelson Education Ltd. Chapter 5: Chemical Processes 5-4

5. Figure 1
6.
Smelting is the chemical process that extracts a metal from its ore using heat and chemicals.
7.
(a) Sulfur dioxide gas contributed to the production of acid rain.
(b) To reduce sulfur dioxide gas emissions, scrubbers were installed to filter out the sulfur dioxide gas emissions before they reached the atmosphere.
(c) Flash smelting was developed to reduce emissions from smelting. In this process, smelting occurs in a pure oxygen environment. This increases the thermal energy released from the reaction, reduces the fuel needed for combustion, and reduces the by-products produced in the reaction.
8.
(a) Copper obtained from the smelting process is not useful in the production of electrical equipment because it is not pure enough for the conduction of electricity.
(b) In the process of electrolysis shown in Figure 3, an impure copper found on the anode is broken down through the use of an electric current. The products produced through this process include pure copper ions and impurities. The pure cooper is deposited on the cathode and the impurities are contained in the electrolyte solution in which the reaction occurs.
9.
(a) Bases can be used to neutralize acids discharged from metallurgical process.
(b) No, it would not be realistic to use a powerful base such as sodium hydroxide to neutralize acid byproducts produced from the mining process that are weakly acidic. A powerful base such as sodium hydroxide may produce excess base in solution. The solution would be transformed from acidic to basic, requiring the need for further neutralization.
1.
(a) Contaminants in land can seep into groundwater supplies, making the water unsafe for animal or human consumption. Contaminants can also bind to the soil, impacting vegetation and animals that may consume this vegetation.
(b) Two methods that can be used to remove contaminants from the land are remediation and total cleanup.
(c) Total cleanup of the land involves the complete removal of all of the hazardous contaminants. Remediation involves treating the contaminated land so that it is safe for use and does not require the complete removal of contaminants.
(d) Remediation is most effective for developing an industrial site into a parking lot because it will make the land safe for that use and not use up money that could be used for other remediation projects.
Copyright © 2011 Nelson Education Ltd. Chapter 5: Chemical Processes 5-5

2.
3.
(a) In the process of soil flushing, large quantities of water are flushed through the soil in an effort to remove the contaminants. The water may be treated with chemicals to bind the contaminants. The water can then be removed from the soil along with the contaminants.
(b) The process of stabilization and solidification converts contaminants to a stable form and then collects them for disposal. Disposal may involve use of a binding agent such as concrete to bury the contaminants.
Chemical oxidation uses chemical reactants pumped into the land to create less hazardous contaminants.
Electrolysis uses electricity to capture pure contaminants and remove them from the soil.
(c) Bioremediation uses organisms to remove contaminants from soil.
(d) Physical and chemical remediation can be costly, energy intensive, and disruptive to the environment.
Bioremediation may be more effective and less disruptive to the environment.
(e) The principle drawback of bioremediation is the it can be more time consuming than physical or chemical remediation.
4.
Phytoremediation involves the use of plants to absorb contaminants in the soil. Plants use their roots to draw up groundwater and contaminants. Some of the contaminants are decomposed at the root of the plant, while others are decomposed in the stems and leaves of the plant.
5.
Plants that cannot decompose contaminants such as metals from the soil and groundwater will accumulate these substances in their roots and structures. Metals collected by these plans can be mined by harvesting the plants.
1.
The phrase “benign by design” means that the design used in specific chemical processes will have little if any (a benign) impact on the environment.
2.
False. As a result of going green, companies have become more profitable and competitive.
3.
Table 1 Benefits and Drawbacks of Going Green
Benefits Drawbacks
• less pollution
• better process outcomes
• less negative impact on the environment
• means to balance environmental concerns with the ability of the organization to make a profit
• Many industrial processes for chemical and product manufacture have been well-established. As such, changing process to create a green alternative may require changing years of policy and practice.
• The development of green chemical processes may require investment on the part of the organization. This will increase the costs associated with green chemical processes over the short term.
Copyright © 2011 Nelson Education Ltd. Chapter 5: Chemical Processes 5-6

4.
Table 2 The Five Principles of Green Chemistry
Principle Concept
1 Use renewable resources as starting materials.
2
3
Use chemicals that have less environmental impact.
Use catalysts to increase reaction efficiency.
4 Use less energy.
5 Reduce and recycle waste.
5.
c
6.
Energy reduction contributes to the development of green chemistry because energy resources needed for chemical production are often generated through the combustion of fossil fuels. Chemicals that take a lot of energy to produce use a lot of fossil fuel. Reducing energy consumption means reducing fossil fuel combustion. Because the combustion of fossil fuels releases harmful greenhouse gases, reductions in fossil fuel use will reduce greenhouse gas emissions.
7. A.
Use raw materials that are environmentally friendly.
B.
Use less energy in the reaction process.
C.
Use a catalyst to increase the speed of the reaction.
D.
Reduce and recycle waste.
8.
True.
Copyright © 2011 Nelson Education Ltd. Chapter 5: Chemical Processes 5-7

Copyright © 2011 Nelson Education Ltd. Chapter 5: Chemical Processes 5-8

1.
c
2.
c
3.
(a) False. The skeleton equation below represents an example of incomplete combustion.
(b) False. The pH of rainwater is typically 5.6.
4.
Combustion is a chemical reaction in which fuel burns in oxygen.
5.
A neutralization reaction is a reaction in which an acid reacts with a base to produce a final solution in which the pH is closer to neutral or 7.0.
6.
Incomplete combustion may be bad for the environment because only part of the energy from a hydrocarbon is released. Incomplete combustion also releases soot and carbon dioxide.
7.
Table 1 Acidic or Basic Oxides
Element Acidic or Basic? carbon acidic sodium calcium nitrogen
8. Figure 1 basic basic acidic
Copyright © 2011 Nelson Education Ltd. Chapter 5: Chemical Processes 5-9

9. Figure 2
1.
b
2.
d
3.
False. Total cleanup of the land means cleaning up the land so that it can be used safely.
4.
c
5.
Mining is a process by which minerals are removed from the ground.
6.
(a) No, a reaction will not occur between bromine and sodium chloride.
(b) This is because bromine is less reactive than sodium, so bromine will not be able to displace sodium in the compound sodium chloride.
7.
(a) Basic
(b) Acidic
8.
No, the strongest base is not always the best choice for neutralizing an acid. Bases used for neutralization must be selected based on their reaction with the acid and the costs of using the base. Some bases may produce violent reactions that create more pollutants. Too much base may make the solution basic rather than neutral, requiring further neutralization.
9.
Table 1 Reaction Types
Equation for Reaction Type
Cu(OH)
2
+ 2 HC
2
H
3
O
2
→ Cu(C
2
H
3
O
2
)
2
+ 2 H
2
O
CH
4
+ 2 O
2
(g) → CO
2
(g) + 2 H
2
O(l)
4 Fe + 3 O
2
(g) → 2 Fe
2
O
3
(s) double displacement combustion synthesis, oxidation
Zn(s) + CuCl
2
(l) → ZnCl
2
(l) + Cu(s)
H
2
SO
4
+ 2 NH
4
OH → (NH
4
)
2
SO
4
+ 2 H
2
O
2 Na
2
(s) + O
2
(g) → 2 Na
2
O(s)
2 HCl(l) → H
2
(g) + Cl
2
(g)
2 C
8
H
18
+ 17 O
2
(g) → 16 CO(g) + 18 H
2
O(l)
Cu(s) + 2 AgNO
3
(aq) → 2 Ag(s) + Cu(NO
3
)
2
(aq) single displacement double displacement, neutralization synthesis decomposition combustion single displacement
Copyright © 2011 Nelson Education Ltd. Chapter 5: Chemical Processes 5-10

10. Figure 1
Copyright © 2011 Nelson Education Ltd. Chapter 5: Chemical Processes 5-11