Question

Match List-I with List-II

List-I		List-II
A	Total nitrogen in soil is determined by	I	Flame photometer
B	Available nitrogen is determined by	II	Alkaline permanganate method
C	K and B is determined by	III	Turbidimetric method
D	Sulphate sulphur \(\left(\mathrm{SO_4}\right)\) is determined by	IV	Kjeldahl method

Choose the correct answer from the options given below:

• (A) - (I), (B) - (III), (C) - (II), (D) - (IV)
• (A) - (IV), (B) - (II), (C) - (I), (D) - (III)
• (A) - (II), (B) - (IV), (C) - (III), (D) - (I)
• (A) - (III), (B) - (IV), (C) - (II), (D) - (I)

Hint:

Remember: Available Nitrogen = Alkaline Permanganate; Total Nitrogen = Kjeldahl; Potassium (K) = Flame Photometer; Sulphur = Turbidimetric (Barium Chloride).

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Soil chemical analysis involves specific analytical protocols and instruments designed to extract and quantify different nutrient fractions.

Step 2: Detailed Explanation:
Let us match the parameters with their diagnostic measurement methods:
1. Total nitrogen in soil: Determined quantitatively using the classic Kjeldahl method (involving sulfuric acid digestion, alkali distillation of ammonia, and subsequent titration). Thus, (A) matches with (IV).
2. Available nitrogen: Determined via the alkaline permanganate method (Subbiah and Asija, 1956), where easily hydrolyzable organic nitrogen is oxidized and distilled as ammonia. Thus, (B) matches with (II).
3. Potassium (K): Available potassium is extracted using neutral normal ammonium acetate and measured quantitatively using a Flame photometer. Boron (B) is also commonly grouped in simplified lists under optical emission/spectroscopy. Thus, (C) matches with (I).
4. Sulphate sulphur (\(\text{SO}_4^{2-}\)): Determined using the turbidimetric (or "terbimatric") method, where sulphate ions are precipitated using barium chloride (\(\text{BaCl}_2\)) to form a turbid barium sulphate suspension, measured spectrophotometrically. Thus, (D) matches with (III).
This matches perfectly with option (B).

Step 3: Final Answer:
Therefore, the correct matched sequence is (A) - (IV), (B) - (II), (C) - (I), (D) - (III).