Free Environmental Chemistry MCQs with Answers
221 Environmental Chemistry MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Atmospheric pollution includes smog, acid rain, greenhouse gases, ozone depletion and the effects of carbon monoxide, sulfur oxides, nitrogen oxides and particulate matter. Water pollution covers sewage, industrial waste, eutrophication and treatment stages, while green chemistry focuses on reducing hazardous substances, waste and energy use through safer, more efficient processes.
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221 questions · page 23 of 23
221. COD of water is checked by:
- A. By adding bacteria to the water
- B. Adding chemical oxidizing agent
- C. Both (A) and (B)
- D. None of the above
Explanation: To check the Chemical Oxygen Demand (COD) of water, you typically add bacteria and an oxidizing agent to the water sample. The bacteria help break down the organic matter in the water, while the oxidizing agent helps determine the amount of oxygen required for the oxidation process. By measuring the amount of oxygen consumed, you can determine the COD of the water sample.
Correct answer: Both (A) and (B)