CBSE Questions for Class 11 Medical Chemistry Environmental Chemistry Quiz 11 - MCQExams.com

Ozone hole is widest over
  • Equator
  • North pole
  • North temperate area
  • Antarctica
Ozone layer of upper atmosphere is being destroyed by
  • Chlorofluorocarbon
  • $$SO_2$$
  • Photochemical oxidants/$$O_2$$ and $$CO_2$$
  • Smog
CFCs split up in stratosphere to release chlorine by the action of
  • UV - A
  • UV - B
  • UV - C
  • All of the above
Ozone hole over Antarctica appears during
  • Late August- Early October
  • March- April
  • October- November
  • January- February
Spraying of DDT produces pollution of
  • Air
  • Air and water
  • Air and soil
  • Air, water and soil
Chief air pollutant which is likely to deplete ozone layer is ________.
  • Sulphur dioxide
  • Carbon dioxide
  • Carbon monoxide
  • Nitrogen oxides and fluorocarbons
In coming years, skin related disorders will become more common due to ________.
  • Excessive use of detergents
  • Water pollution
  • Air pollution
  • Depletion of ozone layer
Indiscriminate use of fertilisers causes _______.
  • Air pollution
  • Water pollution
  • Land pollution
  • All of the above
Depletion of ozone layer is due to _______.
  • Oxides of nitrogen
  • Oxides of carbon
  • Oxides of sulphur
  • None of the above
Spraying DDT on crops shall produce pollution of
  • Air and water
  • Air and soil
  • Crops and air
  • Soil and water
Peeling of ozone umbrella is due to
  • CFCs
  • PAN
  • $$CO_2$$
  • Coal burning
According to the recent reports, the country contributed maximum to hole formation in ozone layer is
  • U.S.A.
  • Russia
  • Germany
  • Japan
Among pollutants, which has the most lasting effect?
  • Carbon monoxide
  • Pesticides
  • Sulphur dioxide
  • Smoke from chimneys
Natural sink of stratospheric ozone is?
  • Sulphuric dioxide
  • Sulphur fluxes of oceans
  • Freons
  • HCFCs
Chlorofluorocarbon releases ______ which is harmful to ozone.
  • Fluorine
  • Chlorine
  • Nitrogen peroxide
  • Sulphur dioxide
Ozone hole is caused by
  • Acetylene
  • Ethylene
  • Chlorofluorocarbons
  • Methane
Chlorofluorocarbons are not being used in refrigerators because they
  • Increase temperature
  • Cause allergic reactions
  • Deplete ozone
  • Both A and B
Soil pollutants affecting food chains and food webs by killing microorganisms are
  • Chemical fertilizers
  • Agriculture wastes
  • Pesticides
  • Pathogens
  • $$NO_x$$
Role of CFC present in atmosphere is
  • Reduction in ozone
  • Ozone formation
  • Formation of leghaemoglobin
  • Enhance chlorophyll formation
Ozone hole causes
  • Global warming
  • Reduction in the rate of photosynthesis
  • More ultraviolet rays come to earth
  • All of the above
Chlorofluorocarbons are responsible for
  • Acid rain
  • Ozone layer depletion
  • Global warming
  • Thermal inversion
Result of ozone hole is
  • Green house effect
  • Global warming
  • Acid rain
  • UV radiations reach the earth
Melanin protects us from
  • X-rays
  • Infra-red rays
  • Visible rays
  • UV rays
Identify the wrong statement with reference to UV rays.
  • UV-A is more harmful to animals than UV-B.
  • UV radiation falls in the range between 100-300 nm wavelength.
  • UV radiation is classified into three categories.
  • UV radiation kills microorganisms.
Which of the following statement/s is/are correct with regard to ozone depletion:
The ozone hole is measured in terms of ozone concentrations, which is expressed in Dobson units.
The major cause for ozone depletion is the presence of CFCs in the stratosphere - CFCs are entirely man-made and not found naturally.
  • Only 1
  • Only 2
  • Both A and B
  • None of the above
Snow blindness is cause due to
  • Ozone hole
  • Nuclear winter
  • Acid rain
  • Green house effect
Storm is caused by the _______________.
  • Depletion of ozone layer
  • Presence of high humidity in the atmosphere
  • Rapid accumulation of $$CO_2$$ in the atmosphere
  • Rapid build-up of products of photochemical oxidation of pollutants in the atmosphere
An ozone depleting chemical, which is used in fire- extinguishers is ________.
  • Nitrogen oxide
  • Methyl bromide
  • Halon
  • Chlorofluorocarbon
'Silent Spring' is
  • A piece of literature
  • A valley in Kerala
  • A flower bedecked area in Uttar Kashi
  • An unpolluted area in Kashmir
Depletion of the Ozone layer in the stratosphere is caused by.
  • Carbon monoxide
  • Hydrocarbons
  • Nitrogen dioxide
  • Polychloro-biphenyls
Exposure of UV radiations causes
  • Damage to eye sight
  • Sunburn
  • Skin cancer
  • All of the above
Ozone layer depletion is caused by
  • AFC's
  • BFC's
  • CFC's
  • DFC's
Agricultural use of DDT was banned in India during
  • $$1962$$
  • $$1972$$
  • $$1974$$
  • $$1985$$
When there is depletion of ozone in the stratosphere the wavelength of radiation striking the earth's surface will be ............
  • $$10^{-2}$$ m
  • $$10^{-7}$$ m
  • $$10^{-10}$$ m
  • 100 m
Soil is a natural medium for growth of land plants. Organic soil contains organic number upto a depth of
  • Two and a half feet
  • One foot
  • Six inches
  • Ten feet
Match the column I with column II and mark the appropriate choice
Column IColumn II
(A) Troposphere(i) Prevents UV rays coming to earth
(B) Stratosphere(ii) Ionization of gases
(C) Mesosphere(iii) Maintenance of heat balance
(D) Thermosphere(iv) Non-propagation of sound waves
  • $$(A)\rightarrow (i),(B)\rightarrow (iv),(C)\rightarrow (iii),(D)\rightarrow (i)$$
  • $$(A)\rightarrow (iv),(B)\rightarrow (ii),(C)\rightarrow (i),(D)\rightarrow (iii)$$
  • $$(A)\rightarrow (iii),(B)\rightarrow (i),(C)\rightarrow (iv),(D)\rightarrow (ii)$$
  • $$(A)\rightarrow (i),(B)\rightarrow (iii),(C)\rightarrow (ii),(D)\rightarrow (iv)$$
Ozone is present in:
  • troposphere
  • stratosphere
  • mesosphere
  • exosphere
Region/regions of the atmosphere where temperature decreases with altitude is/are:
  • thermosphere
  • stratosphere
  • troposphere
  • ozonosphere
Which of the following statements is false?
  • The main reason for river water pollution is industrial and domestic sewage discahrge
  • Surface water contains a lot of organic matter, mineral nutrients and radioactive materials
  • Oil spills in sea water causes heavy damage to fishery
  • Oil slick in a sea water increases DO value
Match the column I with column II and mark the appropriate choice.
Column IColumn II
(A)Peroxyacetyl nitrate(i)Global warming
(B)Polychlorinated biphenyls(ii)Photochemical smog
(C)Dioxides of carbon and sulphur(iii)Water pollutant
(D)IR active molecules(iv)Acid rain
  • (A) $$\rightarrow$$ (ii), (B) $$\rightarrow$$ (iii), (C) $$\rightarrow$$ (iv), (D) $$\rightarrow$$ (i)
  • (A) $$\rightarrow$$ (iii), (B) $$\rightarrow$$ (iv), (C) $$\rightarrow$$ (ii), (D) $$\rightarrow$$ (i)
  • (A) $$\rightarrow$$ (iv), (B) $$\rightarrow$$ (ii), (C) $$\rightarrow$$ (iii), (D) $$\rightarrow$$ (i)
  • (A) $$\rightarrow$$ (i), (B) $$\rightarrow$$ (iii), (C) $$\rightarrow$$ (ii), (D) $$\rightarrow$$ (iv)
Which of the following is responsible for the depletion of the ozone layer in the upper stratosphere of the atmosphere?
  • Polyhelogens
  • Ferrocenes
  • Fullerenes
  • Freons
In Antarctica ozone depletion is due to the formation of following compound.
  • Acroline
  • Chlorine nitrate
  • Formyldehyde
  • $$SO_3$$ and $$SO_2$$
Which of the following is the uppermost layer of the atmosphere?
  • Stratosphere
  • Mesosphere
  • Ionosphere
  • Exosphere
10 mL of water required 1.47 mg of $$K_{2}Cr_{2}O_{7}$$ (M. wt. = 294) for oxidation of dissolved organic matter in presence of acid. Then the C.O.D of water sample is:
  • 2.44 ppm
  • 24 ppm
  • 32 ppm
  • 1.6 ppm
Match the column I with column II and mark the appropriate choice.

Column I
(Pollutants)
Column II
(Source)
(a)Toxic heavy metals(i)Domestic sewage
(b)Microorganisms(ii)Industries and chemical factories
(c)Organic wastes(iii)Chemical fertilizers
(d)Plant nutrients(iv)Discharge from food processing factories
  • (a) $$\rightarrow$$ (i), (b) $$\rightarrow$$ (iii), (c) $$\rightarrow$$ (ii), (d) $$\rightarrow$$ (iv)
  • (a) $$\rightarrow$$ (iii), (b) $$\rightarrow$$ (iv), (c) $$\rightarrow$$ (i), (d) $$\rightarrow$$ (ii)
  • (a) $$\rightarrow$$ (iv), (b) $$\rightarrow$$ (ii), (c) $$\rightarrow$$ (iii), (d) $$\rightarrow$$ (i)
  • (a) $$\rightarrow$$ (ii), (b) $$\rightarrow$$ (i), (c) $$\rightarrow$$ (iv), (d) $$\rightarrow$$ (iii)
Which of the following practices involve green chemistry?
(i) Substitute CFCs by environmental friendly HFCs and other compounds.
(ii) Replace halogenated solvent by liquid $$CO_{2}$$ for drycleaning.
(iii) Use of $$H_{2}O$$ for bleaching instead of $$Cl_{2}$$
(iv) Making disposable eating utensils and storage jars of plastics.
  • (i) and (ii)
  • (ii) and (iv)
  • (iii) and (iv)
  • (i), (ii) and (iii)
Which of the following practices will come under green chemistry?
  • If possible, making use of soap made of vegetable oils instead of using synthetic detergents
  • Using $$H_{2}O$$ for bleaching purpose instead of using chlorine based bleaching agents
  • Using bicycle for travelling small distances instead of using petrol/diesel based vehicles
  • All of these
Mark the example which in not correctly matched?
  • Air pollutants - Oxides of sulphur, nitrogen and carbon
  • Particulate pollutants - Dust, mist fumes
  • Global warming - Methane, ozone, CFCs
  • Water soluble chemical pollutants - Oxides of nitrogen, carbon and sodium
Temperature of troposphere decreases with altitude. This is because of_____.
  • high pressure of air
  • gases present in air
  • low density of air
  • all of these
What does $$BO{D}_{5}$$ represent?
  • Biological oxygen demand in five days
  • Dissolved oxygem left after five days
  • Dissolved oxygen consumed in five days
  • Microorganisms killed by ozone in sewage treatment plants in five hours
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