Practice Start Test

Environmental Chemistry

NEET Chemistry · 96 questions · Page 8 of 10 · Click an option or "Show Solution" to reveal answer

Q71
The presence of ozone in troposphere :
A protects us from greenhouse effect
B protects us from the UV radiation
C protects us from the X-ray radiation
D generates photochemical smog
Correct Answer
Option D
Solution

Ozone is a strong oxidising agent like NO2.

In troposphere both O3 and NO2 react with the unburnt hydrocarbons to produce the chemical components of photochemical smog, like formaldehyde (HCHO), acrolein (CH2 = CH - CHO) and PAN or peroxyacetyl nitrate.

Hence, in troposphere, the presence of ozone generates photochemical smog.

Q72
A water sample has ppm level concentration of following anions F- = 10; SO42−SO_4^{2-} = 100; NO3−NO_3^- = 50 The anion/anions that make/makes the water sample unsuitable for drinking is/are :
A both SO42−SO_4^{2-} and NO3−NO_3^-
B only F-
C only SO42−SO_4^{2-}
D only NO3−NO_3^-
Correct Answer
Option B
Solution

Permissible limit for SO4 2- = 500 ppm Permissible limit for NO3 - = 50 ppm Permissible limit for F- = 1 ppm

Q73
Given below are two statements : Statement I : The value of the parameter "Biochemical Oxygen Demand (BOD)" is important for survival of aquatic life. Statement II : The optimum value of BOD is 6.5 ppm. In the light of the above statements, choose the most appropriate answer from the options given below :
A Statement I is false but Statement II is true
B Statement I is true but Statement II is false
C Both Statement I and Statement II are true
D Both Statement I and Statement II are false
Correct Answer
Option B
Solution

Clean water would have BOD value of less than 5 ppm whereas highly polluted water could have a BOD value of 17 ppm or more.

Hence, the value of parameter ‘BOD’ is important for survival of aquatic life but optimum value of BOD is 17 ppm or more.

So, statement II is incorrect.

Q74
Some gases are responsible for heating of atmosphere (green house effect). Identify from the following the gaseous species which does not cause it.
A CH4
B O3
C H2O
D N2
Correct Answer
Option D
Solution

Among the given gases, the green house gases which are responsible for heating the atmosphere are CH4, water vapour and ozone.

Nitrogen is not a green house gas.

Q75
Which of the following conditions in drinking water causes methemoglobinemia?
A > 50 ppm of lead
B > 50 ppm of chloride
C > 50 ppm of nitrate
D > 100 ppm of sulphate
Correct Answer
Option C
Solution

Concentration of nitrate > 50 ppm in drinking water causes methemoglobinemia

Q76
The concentration of dissolved Oxygen in water for growth of fish should be more than X‾\mathrm{\underline X } ppm and Biochemical Oxygen Demand in clean water should be less than Y‾\mathrm{\underline Y } ppm. X and Y in ppm are, respectively.
A .tg td{border-color:black;border-style:solid;border-width:1px;font-family:Arial, sans-serif;font-size:14px; overflow:hidden;padding:10px 5px;word-break:normal;} .tg th{border-color:black;border-style:solid;border-width:1px;font-family:Arial, sans-serif;font-size:14px; font-weight:normal;overflow:hidden;padding:10px 5px;word-break:normal;} .tg .tg-baqh{text-align:center;vertical-align:top} X\mathrm{X} Y\mathrm{Y} 4 15
B .tg td{border-color:black;border-style:solid;border-width:1px;font-family:Arial, sans-serif;font-size:14px; overflow:hidden;padding:10px 5px;word-break:normal;} .tg th{border-color:black;border-style:solid;border-width:1px;font-family:Arial, sans-serif;font-size:14px; font-weight:normal;overflow:hidden;padding:10px 5px;word-break:normal;} .tg .tg-baqh{text-align:center;vertical-align:top} X\mathrm{X} Y\mathrm{Y} 4 8
C .tg td{border-color:black;border-style:solid;border-width:1px;font-family:Arial, sans-serif;font-size:14px; overflow:hidden;padding:10px 5px;word-break:normal;} .tg th{border-color:black;border-style:solid;border-width:1px;font-family:Arial, sans-serif;font-size:14px; font-weight:normal;overflow:hidden;padding:10px 5px;word-break:normal;} .tg .tg-baqh{text-align:center;vertical-align:top} X\mathrm{X} Y\mathrm{Y} 6 12
D .tg td{border-color:black;border-style:solid;border-width:1px;font-family:Arial, sans-serif;font-size:14px; overflow:hidden;padding:10px 5px;word-break:normal;} .tg th{border-color:black;border-style:solid;border-width:1px;font-family:Arial, sans-serif;font-size:14px; font-weight:normal;overflow:hidden;padding:10px 5px;word-break:normal;} .tg .tg-baqh{text-align:center;vertical-align:top} X\mathrm{X} Y\mathrm{Y} 6 5
Correct Answer
Option D
Solution

For high growth, dissolved oxygen should be less than 6 ppm and clean water has dissolved oxygen less than 5 ppm.

Q77
Which is wrong with respect to our responsiblity as a human being to protect our environment?
A Restricting the use of vehicles
B Setting up compost tin in gardens.
C Avoiding the use of floodlighted facilities
D Using plastic bags.
Correct Answer
Option D
Solution

Plastic bag is harmful for our eviroment an plastic is non bio-degradable polutant.

Q78
The condition that indicates a polluted environment is :
A BOD value of 5 ppm
B eutrophication
C 0.03% of CO2 in the atmosphere
D pH of rain water to be 5.6
Correct Answer
Option B
Solution

In Eutrophication nutrient enriched water bodies support a dense plant population, which kills animal life by depriving it of oxygen and results in subsequent loss of biodiversity.

If indicates polluted environment.

Q79
The photochemical smog does not generally contain :
A NO
B NO2
C SO2
D HCHO
Correct Answer
Option C
Solution

Photochemical smog contain: Ozone, nitric oxide, organic compounds, nitrogen dioxide, formaldehyde.

∴SO2\therefore \mathrm{SO}_{2}

is not the part of photochemical smog.

Q80
BOD stands for :
A Biological Oxygen Demand
B Bacterial Oxidation Demand
C Biochemical Oxygen Demand
D Biochemical Oxidation Demand
Correct Answer
Option C
Solution

BOD stands for Biochemical Oxygen Demand.

Ready for a full NEET mock test? Timed · full syllabus · instant results
Take a Mock Test →