Introduction to Air Pollutants & Troposhpheric Pollutants

Q. Ozone hole refers to –

1. Increased concentration of ozone
2. Reduction in the thickness of ozone layer in troposphere
3. Reduction in the thickness of ozone layer in stratosphere
4. Hole in ozone layer

Q. Which one of the following statement s in not true?

1. Clean water would have a BOD value of 6 ppm.
2. Fluoride deficiency in drinking water is harmful. Soluble fluoride is used to bring its concentration upto 1ppm.
3. When the pH of rain water is higher than 6.5, it is called acid rain.
4. Dissolved Oxygen (DO) in cold water can reach a concentration upto 10 ppm.

Q. Green chemistry involves?

1. production of chemicals of our daily use from green house gases
2. such chemical processes in which green plants are used
3. those reaction which are of biological origin
4. use of non-toxic reagents and solvents to produce environment friendly products

Q.

Which of the following is not an example of green chemistry?

1. Calalytic dehydrogenation of the diethanol amine without using cyanide and formaldehyde

2. Replacement of CFC's by $C{O}_2$ as blowing agent in the manufacture of polystyrene from sheets

3. Reacting methylamine and phosgene to produce methyl isocyanate

4. Replacement of organotins by 'sea-nine' as antifouling compounds in sea marine.

Q. $CFC{l}_3$ is responsible for the decomposition of ozone layer. Which of the following reacts with ozone to form oxygen?

1. $C{l}_2$
2. $C{l}^{-}$
3. $F^{-}$
4. $C{l}^{\ast }$

Q.

The smog is essentially caused by the presence of

1. $O_{2}and{O}_3$

2. $O_{3}and{N}_2$

3. Oxides of sulphur and nitrogen

4. $O_{2}and{N}_2$

Q. Name the regions of the atmosphere where oxygen and ozone play key roles respectively-

1. mesosphere , startospherer
2. troposphere, stratosphere
3. ionosphere , exosphere
4. ozonesphere , thermosphere

Q. Match the pollutants involved in the contamination of water bodies with their sources.
$\begin{array}{cc}\text{Pollutants}& \text{Source}\\ \text{(A) Microorganisms}& \text{(1) Chemical fertilizers}\\ \text{(B) Heavy metals}& \text{(2) Industrial effluents}\\ \text{(C) Sediments}& \text{(3) Domestic sewage}\\ \text{(D) Phosphorus and nitrogen}& \text{(4) Run off from plains}\end{array}$

1. A-3, B-2, C-4, D-1
2. A-2, B-5, C-3, D-1

3. A-1, B-3, C-2, D-4

4. A-4, B-2, C-1, D-5

Q. Which of the following pairs is secondary precursors of photochemical smog –

1. $S{O}_{2}andN{O}_2$
2. $S{O}_2$ and hydrocarbons
3. $N{O}_2$ and hydrocarbons
4. $O_3$ and PAN

Q. Which of the following is a sink for CO?

1. Microoraganisms present in the soil
2. Oceans
3. Plants
4. Haemoglobin

Q. Which of the following is the major air pollutant?

1. ${\text{CO}}_2$
2. ${\text{NO}}_2$
3. $\text{CO}$
4. ${\text{SO}}_2$

Q. Consider the following observations:
(I) The $pH$ of rain water is $5.6$.
(II) The amount of $C{O}_2$ in the atmosphere is 0.03%.
(III) The biochemical oxygen demand is $10ppm$.
(IV) Eutrophication.
A polluted environment is observed under:

1. Both I and III
2. Both I and IV
3. Both III and IV
4. I, III, and IV

Q. When rain is accompanied by a thunderstorm, the collected rain water will have a pH value

1. slightly higher than that when the thunderstorm is not there
2. uninfluenced by occurrence of thunderstorm
3. which depends on the amount of dust in air
4. slightly lower than that of rain water without thunderstorm

Q.

Atmospheric pollution is generally studied as:

1. Tropospheric pollution

2. Stratospheric pollution

3. Both the above

4. None of these

Q.

Particulate air pollutants include:

1. Dust

2. Smoke

3. Smog

4. All of these