Environmental Chemistry

NEET Chemistry · 96 questions · Page 9 of 10 · Click an option or "Show Solution" to reveal answer

Q81

Correct statement about photo-chemical smog is :

A It occurs in humid climate.

B It is a mixture of smoke, fog and SO2.

C It is reducing smog.

D It results from reaction of unsaturated hydrocarbons.

Correct Answer

Option D

Solution

Photochemical smog occurs in warm, dry and sunny climate.

The main components of photochemical smog result from the action of unsaturated hydrocarbons and nitrogen oxides.

This is an oxidising smog.

Q82

Which one of the following substances used in dry cleaning is a better strategy to control environmental pollution?

A Tetrachloroethylene

B Carbon dioxide

C Sulphur dioxide

D Nitrogen dioxide

Correct Answer

Option B

Solution

Out of the given options, the substance that is a better strategy to control environmental pollution in dry cleaning is carbon dioxide (CO2).

Option A: Tetrachloroethylene, also known as perchloroethylene (PERC), is a commonly used solvent in dry cleaning.

However, it is a hazardous air pollutant and a potential human carcinogen.

Its use has been restricted or banned in many countries due to its harmful effects on the environment and human health.

Option B: Carbon dioxide is a more environmentally friendly alternative to traditional dry cleaning solvents like PERC.

CO2 is a non-toxic, non-flammable, and readily available gas that can be used as a cleaning solvent when it is in its supercritical state.

CO2 dry cleaning is a "green" process that does not produce hazardous waste or emit harmful air pollutants.

Option C: Sulphur dioxide (SO2) is a common air pollutant that is emitted from the burning of fossil fuels.

It is not used as a dry cleaning solvent, and its use would not be an effective strategy to control pollution in dry cleaning.

Option D: Nitrogen dioxide (NO2) is also a common air pollutant that is emitted from the burning of fossil fuels.

It is not used as a dry cleaning solvent, and its use would not be an effective strategy to control pollution in dry cleaning.

Therefore, the correct option is Carbon dioxide.

Q83

The gas released during anaerobic degradation of vegetation may lead to :

A Ozone hole

B Corrosion of metals

C Acid rain

D Global warming and cancer

Correct Answer

Option D

Solution

Methane (CH4) gas is evolved due to anaerobic degradation of vegetation which causes global warming and cancer.

It is a heat trapping gas that forces the planet to warm drastically and quickly.

Q84

Formation of photochemical smog involves the following reaction in which

\mathrm{A}, \mathrm{B}

and

\mathrm{C}

are respectively.

\begin{aligned} & \text{ i. } \mathrm{NO}_{2} \stackrel{\mathrm{h} v}{\longrightarrow} \mathrm{A}+\mathrm{B} \\ & \text{ ii. } \mathrm{B}+\mathrm{O}_{2} \rightarrow \mathrm{C} \\ & \text{ iii. } \mathrm{A}+\mathrm{C} \rightarrow \mathrm{NO}_{2}+\mathrm{O}_{2} \end{aligned}

Choose the correct answer from the options given below :

\mathrm{NO}, \mathrm{O} ~\& ~\mathrm{O}_{3}

\mathrm{N}, \mathrm{O}_{2} ~\& ~\mathrm{O}_{3}

\mathrm{O}, \mathrm{N}_{2} \mathrm{O} ~\& ~\mathrm{NO}

\mathrm{O}, \mathrm{NO} ~\mathrm{\&} ~\mathrm{NO}_{3}^{-}

Correct Answer

Option A

Solution

(i)

N{O_2}\overset{{hv}}\longrightarrow {{NO} \over {(A)}} + {O \over {(B)}}

(ii)

{O \over {(B)}} + {O_2}\overset{{}}\longrightarrow {{{O_3}} \over {(C)}}

(iii)

{{NO} \over {(A)}} + {{{O_3}} \over {(C)}}\overset{{}}\longrightarrow N{O_2} + {O_2}

Q85

Among the gases (a) – (e), the gases that cause greenhouse effect are : (a) CO2 (b) H2O (c) CFCs (d) O2 (e) O3

A (a), (b), (c) and (d)

B (a) and (d)

C (a), (b), (c) and (e)

D (a), (c), (d) and (e)

Correct Answer

Option C

Solution

CO2, O3, H2O, CFCs are green house gases. Here only O2 is not greenhouse gas.

Q86

The processes of calcination and roasting in metallurgical industries, respectively, can Iead to :

A Global warming and photochemical smog

B Photochemical smog and ozone layer depletion

C Photochemical smog and global warming

D Global warming and acid rain

Correct Answer

Option D

Solution

Calcination Releases $\to$ CO2 $\to$ Global warming Roasting Releases $\to$ SO2 $\to$ Acid Rain

Q87

Thermal power plants can lead to :

A Ozone layer depletion

B Blue baby syndrome

C Eutrophication

D Acid rain

Correct Answer

Option D

Solution

Thermal power plants lead to acid rain.

Q88

Given below are two statements : Statement I : The pH of rain water is normally 5.6. Statement II : If the pH of rain water drops below 5.6, it is called acid rain. In the light of the above statements, choose the correct answer from the options given below :

A Both Statement I and Statement II are true.

B Both Statement I and Statement II are false.

C Statement I is true but Statement II is false.

D Statement I is false but Statement II is true.

Correct Answer

Option A

Solution

Option A Both Statement I and Statement II are true.

Explanation : The pH of pure water is 7, which is considered neutral.

However, rainwater is naturally slightly acidic due to the presence of dissolved carbon dioxide, which reacts with the water to form carbonic acid.

The pH of "normal" rainwater is around 5.6 because of this natural process.

Acid rain is a term that refers to any form of precipitation with acidic components, such as sulfuric or nitric acid, that fall to the ground from the atmosphere in wet or dry forms.

This can include rain, snow, fog, hail or even dust that is acidic.

The increased acidity in rain is caused by high amounts of pollutant components such as sulfur and nitrogen compounds which react in the atmosphere with water, oxygen, and other chemicals to form sulfuric and nitric acid.

These then fall to the ground as acid rain.

The generally accepted definition of "acid rain" refers to rainfall with a pH of less than 5.6, which is more acidic than normal rainwater.

Q89

The possibility of photochemical smog formation is more at :

A Industrial areas

B Himalayan villages in winter

C The places with healthy vegetation

D Marshy lands

Correct Answer

Option A

Solution

Photochemical smog is a type of air pollution that results from the interaction between sunlight and pollutants such as nitrogen oxides and volatile organic compounds (VOCs).

This type of smog is common in urban and industrial areas where there is a high concentration of these pollutants.

The conditions favorable for the formation of photochemical smog include strong sunlight, stagnant air, and the presence of pollutants such as those emitted by vehicles and industrial processes.

Given the options: Option A : Industrial areas - These typically have a high concentration of pollutants like nitrogen oxides and VOCs that can interact with sunlight to form photochemical smog.

Option B : Himalayan villages in winter - Likely to have less sunlight and fewer pollutants.

Option C : The places with healthy vegetation - Vegetation can actually help to reduce smog by absorbing pollutants.

Option D : Marshy lands - Unlikely to have the concentration of pollutants necessary for photochemical smog formation.

The correct answer is : Option A : Industrial areas.

Q90

The regions of the atmosphere, where clouds form and where we live, respectively, are :

A Stratosphere and Stratosphere

B Stratosphere and Troposphere

C Troposphere and Stratosphere

D Troposphere and Troposphere

Correct Answer

Option D

Solution

The lowest region of atmosphere in which human beings live is troposphere.

It extends up to a height of 10 km from sea level.

Clouds are also formed in this layer

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