Environmental Chemistry – Sections 1.1 to 1.3
Answer these questions on a separate sheet
1.1 Chemicals in the Environment
A. Chemicals in the Environment
1. Name three chemicals in the environment that are important for life. Carbon Dioxide, Oxygen and H2O
2. Name three chemicals in the environment that are harmful for life. Too much Carbon Dioxide, Sulphur Dioxide,
Ash
3. Name two natural sources of chemicals in the environment and name an artificial source of chemicals in the
environment. Natural – Forest fires, volcanoes
Artificial – burning of fossil fuels, pesticides
B. The Nitrogen Cycle
1. Explain what nitrogen fixation is. Changing free nitrogen so that the nitrogen can be combined with other
elements to make compounds that organisms can use.
2. What kind of organism helps fix nitrogen and explain how they do this? Bacteria...they separate the nitrogen
into two atoms, and these two atoms can then combine with other elements to make useful compounds.
3. Please draw the nitrogen cycle and explain it in your own words. (Drawing and explanation on page 185)
Nitrogen moves from the air to the soil, once in the soil bacteria fix the nitrogen so it can be used by plants and
some is returned to the air, animals then eat the plants and consume the nitrogen, animal waste then returns the
nitrogen to the soil where decomposers break it down again so it can be used by plants.
C. Human Activities
1. Talk about the following human activities by explaining how they can cause harm to the environment by
changing the chemistry of the environment: Fertilizer, Pesticides, Solid Wastes, Wastewater, Fuel Combustion
Fertilizer – Too much fertilizer can harm plants and fertilizer can run into water and cause the water to change
chemically
Pesticides – Some pesticides kill target and non target animals, pesticides also stay in the environment for a long
time
Solid Wastes – Some solid waste is incinerated and this releases chemicals into the air, also there leaking of
chemicals from garbage in landfills into the soil
Wastewater – Some rain water will wash right into rivers and it contains oils and other pollutants that causes
problems in the water, also waste effluent is released into water which contains chemicals that can cause harm to
the water it enters
Fuel Combustion – burning of fossil fuels releases large amounts of carbon dioxide into the air as well as other
pollutants such as sulphur dioxide, nitrogen oxides and lead
1.2 Acids and Bases
A. pH and pH Scale
1. What is pH? (2 sentences to explain on page 191) pH indicates the acidity of a solution...it is a measure of the
hydrogen ions in a solution
2. What is an acid? A compound that dissolves in water to form a solution with a pH lower than 7
3. What is a base? A compound that dissolves in water to form a solution with a pH higher than 7
4. Please draw the pH scale on page 191 and add the following labels on your scale: strong acid, strong base,
neutral, stomach acid, lemon juice, milk, distilled water, toothpaste, normal rain, drain cleaner, most animals are
dead.
B. Measuring pH
1. What are the two ways we can measure pH? Can use a pH meter, or you can use acid-base indicator strips
C. Neutralization
1. What is neutralization? A reaction between an acid and a base
2. What pH do products of neutralization have? Neutralized products have a pH of 7
D. Acid Rain
1. Explain why rain is naturally slightly acidic. Raindrops dissolve carbon dioxide from the air to produce a weak
carbonic acid
2. What causes acid rain? This is not in the text but you should know this anyway. Air pollution causes acid rain
3. What can acid rain do the ecosystems? Can cause lakes to become too acidic that organisms can’t live in it
4. How do we treat lakes that have become acidic because of acid rain and acid runoff? Explain. Lakes are
sometimes treated with lime which is a base, to help neutralize the acid
Common Substances Essential to Living Things
A. Organic vs. Inorganic
1. Please copy this into your notes:
Organic compounds are large complex molecules made up of carbon with hydrogen, oxygen and nitrogen.
Inorganic compounds are substances that do not contain carbon (except carbon oxides like carbon dioxide and
carbonate compounds)
B. Macronutrients vs. Micronutrients
1. What are nutrients? Elements and compounds that living things need for living, growing and reproducing
2. What are macronutrients and name the 9 nutrients that make up macronutrients? Nutrients that are needed in
large amounts...carbon, hydrogen, oxygen, nitrogen, phosphorous, potassium, magnesium, calcium and sulphur
3. What are micronutrients? Elements or compounds needed in small or trace amounts but that are still important
C. Nutrient Levels
1. Please copy the following into your notes:
Too much or too little of any nutrient can have harmful side effects.
D. Carbohydrates
1. What are carbohydrates (back of book) and what do they form? Name a simple substance they form and a
complex substance they form. Organic materials made of atoms of carbon, hydrogen and oxygen. Can form simple
substances such as sugar or complex substances such as starch, cellulose and glycogen
2. Where do we find carbohydrates and what do they provide our body with? Find carbs in pasta, rice, fruits and
breads…provide us with energy
3. What atoms are carbohydrates made of? Carbon, hydrogen and oxygen
E. Lipids
1. What are lipids (back of book) and what atoms are they made of? Organic molecules made up of carbon,
hydrogen and oxygen
2. Where do we find lipids? Find lipids in fats, oils, nuts, meat, peanut butter
F. Proteins
1. What is a protein and what atoms are proteins made of? An organic compound made of units called amino
acids...made of carbon, hydrogen, oxygen and nitrogen
2. How many amino acids does a typical protein contain? Contains between 40 to 500 amino acids
3. What do we use proteins for? Proteins help with the growth and repair of body tissues (muscle) and to make
enzymes and hormones
4. Where do we find proteins? Meat, eggs, dairy products
F. Nucleic Acids
1. Copy this in your notes: Nucleic acids are organic compounds made up of C, H, O and N
2. Nucleic acid is the building block of what two important things? Building block of DNA and RNA...RNA helps
transport genetic material for DNA
3. DNA and RNA are made of what three substances? Phosphates, ribose (simple sugar) and nitrogen
4. Copy this to your notes: Nucleic acids are the most complicated molecules found in living things.