Environmental Chemistry · JEE Main previous year questions

2021 4 questions

1. Q752021 · 1 Sept 2021 · Shift 2

   Water sample is called cleanest on the basis of which one of the BOD values given below :

   1. A.11 ppm
   2. B.15 ppm
   3. C.3 ppm
   4. D.21 ppm
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   Answer: C

2. Q722021 · 20 Jul 2021 · Shift 1

   Green chemistry in day-to-day life is in the use of :

   1. A.Chlorine for bleaching of paper
   2. B.Large amount of water alone for washing clothes
   3. C.Tetrachloroethene for laundry
   4. D.Liquified ${\text{CO}}_2$ for dry cleaning of clothes
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   Answer: D

3. Q762021 · 18 Mar 2021 · Shift 1

   The statements that are TRUE : (A) Methane leads to both global warming and photochemical smog (B) Methane is generated from paddy fields (C) Methane is a stronger global warming gas than $\mathrm{C}{\mathrm{O}}_2$ (D) Methane is a part of reducing smog Choose the most appropriate answer from the options given below :

   1. A.(A), (B), (C) only
   2. B.(A) and (B) only
   3. C.(B), (C), (D) only
   4. D.(A), (B), (D) only
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   Answer: A

4. Q742021 · 16 Mar 2021 · Shift 1

   The type of pollution that gets increased during the day time and in the presence of ${\mathrm{O}}_3$ is :

   1. A.Oxidising smog
   2. B.Global warming
   3. C.Acid rain
   4. D.Reducing smog
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   Answer: A