6.4 Acid Deposition

Question 1

Acid Deposition

Answer 1

process by which acidic particles, gases, and precipitation are deposited on Earth’s surface, including both wet deposition (rain, snow) and dry deposition (dust, aerosols).

Question 2

Formation of acid rain (reactions)

Answer 2

Acid rain forms when sulfur dioxide (SO2) and nitrogen oxides (NOx) are released into the atmosphere, react with water vapor, oxygen, and other chemicals, forming sulfuric acid (H2SO4) and nitric acid (HNO3).

Question 3

pH of acid rain

Answer 3

typically ranges from 4.0 to 5.0, which is more acidic than natural rainwater (pH around 5.6).

Question 4

Wet vs Dry Acid Deposition

Answer 4

Dry Deposition: Refers to acidic gases and particles that settle out of the atmosphere

Wet Deposition: Involves acids being removed from the atmosphere by precipitation (rain, snow).

Question 5

Natural sources of SO2

Answer 5

volcanic eruptions, sea spray, and decomposition of organic matter.

Question 6

Anthropogenic sources of SO2

Answer 6

burning fossil fuels (coal, oil) and industrial processes,

Question 7

Effect of acid rain on vegetation

Answer 7

can damage leaves, reduce photosynthesis, and leach essential nutrients from the soil, harming plant growth.

Acid rain weakens plants, making them more susceptible to disease, pests, and harsh weather.

Question 8

Why is rain naturally acidic?

Answer 8

it absorbs carbon dioxide (CO2) from the atmosphere as it falls. When CO2 dissolves in rainwater, it forms carbonic acid (H2CO3), a weak acid.

Question 9

Effect of acid rain on (freshwater) aquatic ecosystems

Answer 9

Lowers the pH of water bodies, leading to harmful effects. Sensitive species may die, reducing biodiversity and disrupting ecosystems.

Different from ocean acidification (which is to do with the oceans absorbing CO2)

Question 10

Effect of acid rain on soil

Answer 10

Leaches essential nutrients like calcium and magnesium from the soil, depleting its fertility.

Acid rain can also mobilize toxic metals like aluminum, further harming plant and soil health.

Question 11

Effect of acid rain on humans

Answer 11

contamination of drinking water, reduction of air quality, and damage to crops.

can also lead to respiratory problems

Question 12

Effect of acid rain on buildings

Answer 12

accelerates the deterioration of buildings and monuments, especially those made of limestone, marble.

Acid rain reacts with calcium carbonate in these materials, leading to erosion and structural damage.

Question 13

Downwind vs upwind

Answer 13

Downwind refers to the direction wind is blowing in

Upwind refers to the direction the wind is coming from

Question 14

Prevailing wind

Answer 14

the dominant or most common wind patterns observed in a particular area over a long period

Wind is named the direction it is blowing from, not the direction it is heading towards.

Question 14

Reaction of acid rain with marble/limestone

Answer 14

forms calcium sulfate, which is soluble and washes away, leading to surface erosion.

Chemical Reaction: CaCO3 + H2SO4 → CaSO4 + H2O + CO2

Question 15

Connection between aluminium ions and acid rain

Answer 15

Acid rain can mobilize aluminum ions from soil minerals, which are toxic to plants and aquatic life.

Question 16

Industrial Scrubber

Answer 16

a device (installed in chimneys and smoke stacks) used to remove pollutants, such as SO2, from exhaust gases before they are released into the atmosphere.

Question 17

Liming (application of lime)

Answer 17

Liming involves adding lime (calcium carbonate) to acidic soils or water bodies to neutralize acidity and restore pH balance.

Question 18

Cap and trade

Answer 18

An environmental policy that sets a limit (cap) on total SO2 emissions and allows companies to buy and sell emission permits (trade) to meet their individual caps.

Question 19

Countries still affected by acid rain

Answer 19

China, India, and some Eastern European nations still face significant acid rain issues due to high levels of industrial pollution.

Question 20

High vs low sulfur coal

Answer 20

High sulfur coal contains more sulfur, leading to greater SO2 emissions when burned, whereas low sulfur coal produces fewer emissions.

Question 21

Positive effect of acid rain on peat bogs

Answer 21

The increased acidity can slow down the decomposition of organic material in peat bogs, helping to preserve the bog and its carbon storage capabilities.