Chemistry: Environmental Chemistry: UPSC Previous Year Questions (Science and Technology)
1 previous year UPSC Prelims question on Chemistry: Environmental Chemistry (Science and Technology). Choose an option to see the answer and explanation.
Explanations state facts as of the year each question was asked; words like “recently” refer to that year.
Showing 1–1 of 1 question
UPSC 1998Science and Technology · Chemistry: Environmental Chemistry
Q1. The water pollution in river is measured by the dissolved amount of:
Explanation
Water pollution in rivers is primarily measured by the Dissolved Oxygen (DO) level, which indicates the amount of oxygen available for aquatic organisms. A low DO level signifies high pollution, as pollutants like organic waste decompose and consume oxygen, making the water uninhabitable for aquatic life. BOD (Biochemical Oxygen Demand) is the amount of oxygen required by microorganisms to decompose organic matter in water over a specific period (usually 5 days at 20°C). High BOD indicates organic pollution, such as from sewage or agricultural runoff, while low BOD signifies cleaner water. COD (Chemical Oxygen Demand) is the total amount of oxygen required to chemically oxidize both organic and inorganic matter in water. COD provides a broader measure of pollution than BOD, including oxygen demand from inorganic substances.
Answer key for these questions
Q
UPSC year
Correct answer
1
1998
(d) Oxygen
Frequently asked questions
How many previous year UPSC questions are there on Chemistry: Environmental Chemistry?
This page covers 1 previous year UPSC Prelims GS Paper-I questions on Chemistry: Environmental Chemistry (Science and Technology), asked from 1996 to 2010. Each has the correct answer and an explanation.
How should I use previous year UPSC questions for Prelims?
Attempt each question first, then open the answer and read the explanation for every option. Repeat by chapter, and track which statements UPSC reuses across years. Previous year questions show the exam pattern and difficulty level.
Which years are covered for Chemistry: Environmental Chemistry?
Questions on Chemistry: Environmental Chemistry (Science and Technology) are available for 5 years, from 1996 to 2010. Use the Year filter to practise a single paper.
