MDCAT Chemistry — Environmental Chemistry
Environmental Chemistry is a core Chemistry topic in the PMDC MDCAT syllabus, covering 1 subtopic. Below are the subtopics to revise, how often the topic appears in past papers, and real past-paper MCQs to try.
Subtopics (1)
- Atmospheric Pollution (Acid Rain, Smog)
How Environmental Chemistry is tested
Across the 16 MDCAT past papers on ParhaiKrlo, Environmental Chemistry accounts for 3 questions. It appears in 2 of them, about 1.5 questions a paper. The heaviest was MDCAT 2011, with 2 questions.
| Paper | Questions |
|---|---|
| MDCAT 2011 | 2 |
| MDCAT 2009 | 1 |
Environmental Chemistry MCQs from the MDCAT past papers
Try each one before opening the answer. Each comes with a short explanation.
- Q1 · MDCAT 2011 · Environmental Chemistry
The unpolluted natural rain water is slightly acidic due to the reaction of rain water with:
- A.Sulphur dioxide
- B.Oxides of nitrogen
- C.Carbon dioxide
- D.Hydrogen present in air
Show answer
Answer: C. Carbon dioxide — Even unpolluted rainwater is naturally slightly acidic because atmospheric carbon dioxide dissolves in it, forming weak carbonic acid.
- Q2 · MDCAT 2009 · Environmental Chemistry
The yellowish colour of photochemical smog is due to the presence of:
- A.Nitrogen dioxide
- B.Dinitrogen trioxide
- C.Nitrous oxide
- D.Nitric oxide
Show answer
Answer: A. Nitrogen dioxide — The yellowish-brown color of photochemical smog comes from nitrogen dioxide (NO2).
- Q3 · MDCAT 2011 · Environmental Chemistry
Peroxyacetyl nitrate is an irritant to human beings and it effects:
- A.Nose
- B.Stomach
- C.Ears
- D.Eyes
Show answer
Answer: D. Eyes — Peroxyacetyl nitrate (PAN), a component of photochemical smog, is particularly known as a severe eye irritant to humans.