Environmental Chemistry Booklet Answer Key

Section 1.1

Check and Reflect, Page 190

  1. Decomposers break down large nitrogen-containing molecules from dead organisms and animal waste into nitrogen that can be used to form useful compounds.
  1. Pollution is any change to the environment that produces a condition that is harmful to living things. Examples will vary but could include any of the following: sulfur dioxide, nitrogen oxide, mercury or lead.
  1. The first number represents the percentage of nitrogen compounds in the fertilizer (4%). The second number represents the percentage of phosphorus compounds (6%). The third number represents the percentage of potassium (8%).
  1. A herbicide is a chemical used to kill or control weeds or plants.
  1. Plastic liners and compacted clay are used to prevent solutions from entering groundwater.
  1. Nitrogen is converted into nitrogen containing compounds like nitrates and ammoniums by one of two processes: lightning and bacteria in the soil.
  1. Fossil fuel combustion releases nitrogen and sulfur compounds as well as carbon dioxide. Lead and mercury can also be answers.
  1. Fertilizers are used to supply nutrients to a nutrient-deficient soil so that plants grow better. And increase in crop yield may also be evident.
  1. Sewage has to be treated to remove substances that can have a harmful impact on living things in the environment.
  1. Answers will vary. Riding the bus, car-pooling, riding your bike, etc.
  1. Answers will vary.

Additional Booklet Questions

  1. Volcanoes release 130 million tonnes of carbon dioxide into Earth’s atmosphere every year.
  1. Bacteria are found in these nodules and they are important because they can change (or fix) nitrogen in the soil so other plants can use the nitrogen.
  1. See page 185.
  1. It is estimated that at least 50% of the world’s food production would be lost to pests if pesticides were not used.
  1. Sulfur is used in the manufacturing of sulfuric acid.

Section 1.2

Check and Reflect, Page 195

  1. A neutral solution is one that is neither acidic nor basic. An acid is a compound that dissolves in water to form a solution with a pH lower than 7. A base is a compound that dissolves in water to form a solution with a pH higher than 7.
  1. a) Acid, b) Base, c)neutral solution, d)Base
  1. a) Answers will vary but should include: driving vehicles, power plant emissions and oil and gas refinery; b) carbon dioxide will react with water to form carbonic acid, sulfur dioxide will react with water to form sulfuric acid, nitrogen oxides will react with water to form nitric acid.
  1. pH paper or a universal indicator is a better idea because it will give an accurate representation of pH rather than litmus paper that will tell us whether a substance is just an acid and a base.
  1. When sulfuric acid and sodium hydroxide are mixed, you are mixing an acid and a base and is called a neutralization and therefore a salt and water is formed.
  1. a) An acid could be added to the lake that would neutralize the base.; b) Answers will vary. New species will probably appear at the lower pH while some species will probably disappear.

Additional Booklet Questions

  1. The sting of the bite from a red ant is partly caused by formic acid.
  1. See page 191.
  1. When using a strong base, it could be harmful to the environment if you were to add too much and the solution could become corrosive on the basic end of things.

Section 1.3

Check and Reflect, Page 203

  1. Organic molecules are molecules that have carbon atoms in them. Sugars, starches, proteins, lipids, etc.
  1. Answers will vary. Look on page 197 and check answers against the table located on the bottom half of that page.
  1. A micronutrient is a nutrient that is required in small amounts for survival. Zinc, iron, selenium are all examples of micronutrients.
  1. a) carbon, hydrogen and oxygen, b) carbon, hydrogen, oxygen, nitrogen, c) carbon, hydrogen, oxygen, d) carbon, hydrogen, oxygen, nitrogen, phosphorus
  1. Phosphorus deficiency is a possibility because phosphorus is important in both flower and root growth.
  1. In plants, too little potassium can prevent early growth, reduce disease resistance, reduce starch and protein production, reduce sugar movement, and reduce chlorophyll production and tuber formation. Too much potassium can interfere with the absorption of magnesium. Selenium is needed in small amounts in humans to prevent diseases such cancer, heart disease, cystic fibrosis, and damage to cell membranes cause be hydrogen peroxide. In large amounts, it can cause reproductive problems and death in fish and waterfowl.

Additional Booklet Questions

  1. A glucose molecule is a simple sugar. Glycogen is made up of many different glucose molecules connected by bonds.
  1. Fat molecules are made of the following four parts: 3 fatty acid chains and 1 glycerol molecule.
  1. Enzymes are catalysts that control chemical reactions in living things.
  1. Phosphates, a simple sugar called ribose, and a nitrogen-containing molecule.

Section 1.4

Check and Reflect, Page 209

  1. The substrate for the lichen is a rock.
  1. After ingestion, the food is digested or broken down into smaller particles that can be absorbed into the bloodstream. This process begins in the mouth and continues in the stomach and the small intestine.
  1. Hydrolysis enzymes speed up the rate of digestion.
  1. Water moves into the roots by osmosis. There are more water molecules in the soil than in the plant roots and the water will go from a high concentration to a low concentration.
  1. a) They both have to do with nutrients getting into plant roots.; b) Diffusion requires no energy where active transport requires energy.
  1. Red snow algae photosynthesize. They have lots of sun light in the summer, as well as water from the melting snow for photosynthesis.

Additional Booklet Questions

  1. Nitrogen has to be taken in by a process of active transport. Low concentrations to high concentrations.