Question

Match List - I with List - II.

Choose the correct answer from the options given below :

• A. A-IV, B-II, C-I, D-III
• B. A-III, B-I, C-IV, D-II
• C. A-II, B-III, C-I, D-IV
• D. A-II, B-V, C-III, D-IV

Hint:

Remember the common indicators: EBT for Hardness, Starch for D.O. (Winkler's), and Potassium Chromate for Chloride (Mohr's). These are frequently asked in competitive exams!

Answer 1

The Correct Option is C

Concept: Water quality parameters are determined using specific chemical titration methods or colorimetric tests, each relying on distinct indicators and reagents.

Step 1: Analyze the chemical determination methods.

• Hardness (A): Determined by titration with EDTA (II) (Ethylenediaminetetraacetic acid) using Eriochrome Black T (EBT) as an indicator.
• Chlorine (B): Residual chlorine in water is commonly measured using the Orthotolidine test (III), which produces a yellow color in the presence of chlorine.
• Dissolved Oxygen (C): The standard titrimetric procedure is the Winkler's method (I), which uses iodine titration to measure oxygen levels.
• Chloride (D): Determined via the Mohr's method (IV), which involves titration with silver nitrate ($AgNO_3$) using potassium chromate as an indicator.

Step 2: Match the results.
The correct matching is A-II, B-III, C-I, D-IV.