Equilibrium systems in the environment Term 2

Question 1

What is the atmosphere?

Answer 1

mixture of gases extending 100km above earths surface

Question 2

Define carbon cycle. How can C02 be released into atmosphere?

Answer 2

series of processes by which carbon compounds are interconverted in the environment
-incorporation of carbon dioxide into living tissue by photosynthesis
-carbon dioxides return to atmosphere via respiration, decay of dead organisms, and burning of fossil fuels

Question 3

Examples of how equilibria involving carbon dioxide can occur. What does applying this equilibria allow?

Answer 3

-formation of coral reefs
-production of glucose in plants (photosynthesis)
-respiration in cells and living things
Allows chemistry of process to be understood therefore allowing the effects of change to these systems be predicted

Question 4

Define photosynthesis. What is produced?

Answer 4

Chemical process by which oxygen and glucose are produced in plant cells in the presence of light. Glucose works as an energy source.

Question 5

What is the equation for photosynthesis

Answer 5

6C02(g)+6H20(l)–>C6H1202(aq)+602(g)

Question 6

How does photosynthesis occur? What type of reaction is it?

Answer 6

Involves an endothermic reaction that can only occur in the presence of sunlight and the pigment of chlorophyll found in green parts of plants.
-converts solar energy to chemical energy (used as energy source by all living things during respiration

Question 7

Define respiration. What type of reaction is it?

Answer 7

exothermic reaction in living things where complex organic molecules are oxidised by oxygen by the release of C02, water and energy.
-defined as reverse reaction to photosynthesis

Question 8

What is the equation for respiration

Answer 8

C6H12O6+602—>6CO2+6H20+energy

Question 9

How are non-renewable energy resources formed?

Answer 9

Resources such as coal, oil and natural gas are all non-renewable energy sources formed over a period of almost seven million years from the remains of dead organisms.
-C02 is released when these fuels are burnt as the organisms did not fully decay (therefore CO2 was not released into atmosphere)

Question 10

How does eqm occur in carbon cycle?

Answer 10

When the rate at which carbon enters a stage of the carbon cycle is equal to the rate at which it leaves that same stage.
-the amount of carbon present at each stage is dependent on the rate of entrance/exit

Question 11

What is greenhouse gas? what are the types?

Answer 11

Gases that absorb some infrared radiation before it can reach space and can re-radiate it back towards the earth in the form of heat (global warming)
-C02, water vapour, methane, nitrogen oxides and ozone

Question 12

What is the greenhouse effect? What does it maintain?

Answer 12

process by which earth receives ultraviolet radiation from sun which passes through atmosphere to earths surface. heat radiation from the Earth’s surface is then absorbed and re-emitted by gases in the atmosphere.
-maintains the temperature of the earth at conditions suitable for life

Question 13

How does global warming occur? What causes increase greenhouse gases?

Answer 13

gradual increase in the overall temp of earth’s atmosphere attributed to the greenhouse effect caused by increased levels of greenhouse gases like C02, chlorofluorocarbons, and other pollutants
-due to increase in the use of fossil fuels

Question 14

What happens when greenhouse gases increase?

Answer 14

increase in the infrared radiation absorbed and re-radiated back towards the earth

Question 15

Define enhanced greenhouse effect

Answer 15

an increase in the temperature of Earth’s surface due to an increased concentration of greenhouse gases , as a result of human activities

Question 16

What has been caused due to increased global temperature?

Answer 16

-rising sea levels, shifts in snow/rainfall patterns, severe storms, cyclones, more frequent droughts, intense rainfall and flooding

Question 17

Explain how increasing carbon dioxide levels in the atmosphere is leading to increased ocean acidity.

Why is ocean acidification more prominent in polar regions?

Answer 17

As conc of dissolved carbon dioxide increases, there will be an increase in the concentration of carbonic acid. This, in turn, increases the concentration of H3O=increased ocean acidity.

Carbon dioxide gas is more soluble in cold water=greater ocean acidification in polar regions

Question 18

Describe the process of calcification, including equations.

Answer 18

Ca2+(aq) +CO32-(aq)–>CaCO3(s)
Precipitation of dissolved ions as calcium carbonate in form of shells, coral, structures in marine organisms. Once formed, they are vunerable to dissolution if concs of ions in water change. High acidity levels limit formation of coral/shells

Question 19

Predict the effect on calcification for marine organisms due to increasing ocean acidity and temperature using Le Châtelier’s principle.

Answer 19

Decalcification will occur as ocean becomes more acidic. The additional hydrogen ions react with carbonate ions. The carbonate concentration will therefore be reduced making the formation of calcium carbonate structures more difficult.
pH decrease= calcification decrease.

Question 20

Discuss the United Nations Kyoto Protocol and its outlines in reducing greenhouse gas emissions.

Answer 20

established commitments by 192 countries to reduce greenhouse gas emission’s to specified levels during 2008-2012 by at least 5%.