Quick Review Flashcards - Click to flip and test your knowledge!
Question
From which Latin word is 'pollution' derived, and what does it mean?
Answer
It is derived from 'Pollutus', meaning 'to make unclean'.
Question
What are the two primary categories of sources for atmospheric pollution?
Answer
Natural sources and man-made sources.
Question
Name two natural sources of particulates in the atmosphere.
Answer
Disintegration of rocks and soil.
Question
Which specific oxide of sulphur is the major pollutant in that category?
Answer
$SO_2$ (Sulphur dioxide).
Question
What natural event causes the formation of oxides of nitrogen like $NO$ and $NO_2$?
Answer
Lightning discharge.
Question
The incomplete combustion of petrol primarily produces which carbon-based pollutant?
Answer
Carbon monoxide ($CO$).
Question
Hydrogen sulphide ($H_2S$) is released naturally through which geological event?
Answer
Volcanic eruptions.
Question
What term describes acid rain that falls as rain, snow, fog, or dew?
Answer
Wet deposits.
Question
What do 'dry deposits' of acid rain consist of?
Answer
Particles containing sulphates and nitrates.
Question
Burning fossil fuels accounts for what percentage of man-made $SO_2$ gas?
Answer
70%.
Question
Provide the balanced equation for the oxidation of hydrogen sulphide ($H_2S$) during bacterial decomposition.
Answer
$2H_2S + 3O_2 \rightarrow 2H_2O + 2SO_2$.
Question
What industrial process involves roasting metallic sulphides in air to produce $SO_2$?
Answer
Smelting plants.
Question
At what temperature do nitrogen and oxygen combine in furnaces to form nitric oxide ($NO$)?
Answer
Above $1300^\circ\text{C}$.
Question
Provide the balanced equation for the formation of nitric oxide ($NO$) at high temperatures.
Answer
$N_2 + O_2 \rightarrow 2NO$.
Question
Why is unpolluted natural rain water slightly acidic?
Answer
Carbon dioxide dissolves in it to form weak carbonic acid ($H_2CO_3$).
Question
Provide the balanced equation for the formation of carbonic acid in natural rain.
Answer
$H_2O + CO_2 \rightarrow H_2CO_3$.
Question
What is the typical pH range of natural rain water?
Answer
pH 5 to 6.
Question
Rain is classified as 'acid rain' when its pH falls below what value?
Answer
pH 5.6.
Question
What is the typical pH range of acid rain?
Answer
pH 5.6 to 3.5.
Question
Provide the balanced equation for the reaction of sulphur dioxide with water vapour to form sulphurous acid.
Answer
$H_2O + SO_2 \rightarrow H_2SO_3$.
Question
What substances catalyse the oxidation of $SO_2$ to $SO_3$ in the atmosphere?
Answer
Dust particles and water droplets.
Question
Provide the balanced equation for the formation of sulphuric acid from sulphur trioxide and water vapour.
Answer
$H_2O + SO_3 \rightarrow H_2SO_4$.
Question
Provide the balanced equation for the oxidation of nitric oxide to nitrogen dioxide.
Answer
$2NO + O_2 \rightarrow 2NO_2$.
Question
Provide the balanced equation for the formation of nitrous acid and nitric acid from $NO_2$.
Answer
$H_2O + 2NO_2 \rightarrow HNO_2 + HNO_3$.
Question
Which metals are used as a reduction catalyst in a catalytic converter to separate nitrogen from $NO$ and $NO_2$?
Answer
Platinum ($Pt$) and Palladium ($Pd$).
Question
How does acid rain cause 'nutrient leaching' in soil?
Answer
$H^+$ ions displace minerals like potassium and calcium from the soil.
Question
Which group of soil bacteria has its activity inhibited by acid rain, reducing soil fertility?
Answer
Nitrogen-fixing bacteria (present in leguminous plant nodules).
Question
At what pH level do most aquatic animals, specifically salmons, die?
Answer
Below pH 5.5.
Question
Provide the balanced equation for the damage caused by sulphuric acid to limestone structures.
Answer
$CaCO_3 + H_2SO_4 \rightarrow CaSO_4 + H_2O + CO_2$.
Question
How does C.N.G. (Compressed Natural Gas) compare to petrol in terms of pollution?
Answer
It causes minimum pollution and contains no lead.
Question
What is the 'Greenhouse Effect'?
Answer
The warming of the Earth's surface due to the concentration or blanketing effect of greenhouse gases.
Question
List the four major greenhouse gases identified in the text.
Answer
Carbon dioxide, methane, water vapour, and oxides of nitrogen.
Question
Which greenhouse gas contributes the most to global warming at 55%?
Answer
Carbon dioxide ($CO_2$).
Question
What is the annual rate of increase for Chlorofluorocarbons ($CFCs$) in the atmosphere?
Answer
4%.
Question
Provide the chemical equation for the oxidation of glucose during respiration.
Answer
$C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O$.
Question
Which industrial process involving $CaCO_3$ is a man-made source of $CO_2$?
Answer
The manufacture of quicklime ($CaO$).
Question
Methane ($CH_4$) released from vegetable matter decay is also known as _____.
Answer
Marsh gas.
Question
What is the primary natural source of nitrous oxide ($N_2O$)?
Answer
Anaerobic respiration by microorganisms in the soil.
Question
Which human activity is a major man-made source of both $CH_4$ and $N_2O$?
Answer
Agricultural activities (e.g., rice paddies and fertilizer use).
Question
How does global warming affect sea levels?
Answer
It causes melting of ice-caps, leading to a rise in sea levels and coastal flooding.
Question
What is a significant disadvantage of using hydrogen energy as an alternative fuel?
Answer
Collection and storage of the energy is difficult.
Question
How does afforestation help reduce the greenhouse effect?
Answer
Plants absorb $CO_2$ during photosynthesis.
Question
What is the chemical formula for ozone?
Answer
$O_3$.
Question
In which layer of the atmosphere is the ozone layer primarily located?
Answer
The stratosphere.
Question
At what altitude range is the ozone layer mainly situated?
Answer
Approximately 20-30 km above the Earth.
Question
What unit is used to measure the density of stratospheric ozone?
Answer
The Dobson unit.
Question
Define 'photodissociation' (or photolysis) in the context of ozone formation.
Answer
The process where high energy U.V. radiation breaks an oxygen molecule into two oxygen atoms.
Question
Provide the two-step balanced equations for the formation of ozone in the stratosphere.
Answer
$O_2 \xrightarrow{\text{U.V.}} [O] + [O]$ and $O_2 + [O] \rightarrow O_3$.
Question
What is the 'ozone-oxygen cycle'?
Answer
The continuing process of ozone being produced and destroyed by U.V. light, maintaining a constant concentration.
Question
Which type of ultraviolet radiation is more harmful to humans, animals, and plants: U.V.-A or U.V.-B?
Answer
U.V.-B.
Question
Name two specific health damages caused to humans by depleted ozone and increased U.V. exposure.
Answer
Skin cancer and eye cataracts.
Question
What international treaty was initiated to prevent ozone depletion?
Answer
The Montreal Protocol.
Question
Which group of chemicals is responsible for approximately 80% of ozone depletion?
Answer
Chlorofluorocarbons ($CFCs$).
Question
What specific atom, released from $CFCs$ by U.V. radiation, breaks down ozone molecules?
Answer
Atomic chlorine ($Cl$).
Question
One free chlorine radical can break down over how many ozone molecules?
Answer
100,000.
Question
During which season and over which region are 'ozone holes' most prominent?
Answer
In spring over the Antarctic region.
Question
What is being considered as a substitute for $CFCs$ to help protect the ozone layer?
Answer
$HCFCs$ (Hydrochlorofluorocarbons).
Question
Why is dissolved oxygen essential in water bodies?
Answer
It is necessary for the survival of aquatic life like fishes and plants.
Question
Which mineral in water is essential for bone strength and teeth?
Answer
Calcium.
Question
What role does Zinc play as a beneficial substance in water?
Answer
Production of white blood cells and immune system support.