Environmental Chemistry CBSE Questions & Answers

Environmental Chemistry

This is Chemistry Class 11 Environmental Chemistry CBSE Questions & Answers. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
The ozone layer found high in the stratosphere:
  • A
    Is capable of disintegrating fabric and rubber
  • B
    Protects against the suns harmful UV rays
    Correct
  • C
    Can react with atmospheric pollutants to form smog
  • D
    Is toxic to plants
2
Holes in the ozone layer are thought to have been caused by:
  • A
    Carbon dioxide
  • B
    Space exploration
  • C
    CFC’s
    Correct
  • D
    Methane
3
Which of the following gases is not a green house gas?
  • A
    CO
    Correct
  • B
    \({{\text{O}}_{\text{3}}}\)
  • C
    \({{\text{H}}_{\text{2}}}{\text{O}}\) vapour
  • D
    \({\text{C}}{{\text{H}}_{\text{4}}}\)
4
Photochemical smog occurs in warm, dry and sunny climate. One of the following is not amongst the components of photochemical smog, identify it.
  • A
    \({\text{N}}{{\text{O}}_{\text{2}}}\)
  • B
    Unsaturated hydrocarbon
  • C
    \({{\text{O}}_{\text{3}}}\)
  • D
    \({\text{S}}{{\text{O}}_{\text{2}}}\)
    Correct
5
Which of the following statements is not true about classical smog?
  • A
    Produced in cold and humid climate
  • B
    It contains smoke, fog and sulphur dioxide.
  • C
    Its main components are produced by the action of sunlight on emissions of automobiles and factories.
    Correct
  • D
    It contains compounds of reducing nature.
6
Biochemical Oxygen Demand, (BOD) is a measure of organic material present in water. BOD value less than 5 ppm indicates a water sample to be __________.
  • A
    not suitable for aquatic life.
  • B
    highly polluted.
  • C
    poor in dissolved oxygen.
  • D
    rich in dissolved oxygen.
    Correct
7
Which of the following statements is wrong?
  • A
    Ozone hole is thinning of ozone layer present in stratosphere.
  • B
    Ozone is produced in upper stratosphere by the action of UV rays on oxygen.
  • C
    Ozone is not responsible for green house effect.
    Correct
  • D
    Ozone can oxidise sulphur dioxide present in the atmosphere to sulphur trioxide.
8
Sewage containing organic waste should not be disposed in water bodies because it causes major water pollution. Fishes in such a polluted water die because of
  • A
    Large number of mosquitoes.
  • B
    Decrease in the amount of dissolved oxygen in water.
    Correct
  • C
    Clogging of gills by mud.
  • D
    Increase in the amount of dissolved oxygen.
9
Which of the following statements about photochemical smog is wrong?
  • A
    It has low concentration of oxidising agent.
    Correct
  • B
    Plantation of some plants like pinus helps in controlling photochemical smog.
  • C
    It can be controlled by controlling the release of \({\text{N}}{{\text{O}}_{\text{2}}},\) hydrocarbons, ozone etc.
  • D
    It has high concentration of oxidising agents.
10
The gaseous envelope around the earth is known as atmosphere. The lowest layer of this is extended upto 10 km from sea level, this layer is _________.
  • A
    Hydrosphere
  • B
    Stratosphere
  • C
    Troposphere
    Correct
  • D
    Mesosphere
11
Dinitrogen and dioxygen are main constituents of air but these do not react with each other to form oxides of nitrogen because _________.
  • A
    oxides of nitrogen are unstable.
  • B
    the reaction can be initiated only in presence of a catalyst.
  • C
    the reaction is endothermic and requires very high temperature.
    Correct
  • D
    N2 and O2 are unreactive.
12
The pollutants which come directly in the air from sources are called primary pollutants. Primary pollutants are sometimes converted into secondary pollutants. Which of the following belongs to secondary air pollutants?
  • A
    NO
  • B
    Hydrocarbon
  • C
    CO
  • D
    Peroxyacetyl nitrate
    Correct
13
Which of the following statements is correct?
  • A
    Ozone hole means vanishing of ozone layer around the earth completely.
  • B
    Ozone hole is a hole formed in the troposphere from which ozone oozes out.
  • C
    Ozone hole is thinning of ozone layer of stratosphere at some places.
    Correct
  • D
    Ozone hole is a hole formed in stratosphere from which ozone oozes out.
14
Which of the following practices will not come under green chemistry?
  • A
    If possible, making use of soap made of vegetable oils instead of using synthetic detergents.
  • B
    Using \({{\text{H}}_{\text{2}}}{{\text{O}}_{\text{2}}}\) for bleaching purpose instead of using chlorine based bleaching agents
  • C
    Using plastic cans for neatly storing substances
    Correct
  • D
    Using bicycle for travelling small distances instead of using petrol/diesel based vehicles.
15
Carboxyhaemoglobin does one of the following things if present in human blood
  • A
    reduces the nerve signals
  • B
    reduces the bone strength
  • C
    Oxygen deficiency
    Correct
  • D
    Carbondioxide deficiency