Question

Match List-I with List-II

List-I (Theory proposed) & List-II (Author/formula)
(A) Textural triangle & (I) Sorenson
(B) Ideal gas & (II) Schofield
(C) pH & (III) Whitney
(D) pF & (IV) PV=nRT

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

Hint:

Remember the classic scientific scales:
- pH Scale: Introduced by Sorenson for acidity/alkalinity.
- pF Scale: Introduced by Schofield for soil water suction.
Matching these two instantly guides you to the correct option.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
This matching question covers fundamental principles across soil physics, general chemistry, and physical chemistry.

Step 3: Detailed Explanation:
Let us match each concept in List-I with its correct author or formula in List-II:
- (A) Textural triangle $\rightarrow$ Whitney (III): Milton Whitney designed the original soil textural triangle to classify soil textural classes based on the relative percentages of sand, silt, and clay.
- (B) Ideal gas $\rightarrow$ PV=nRT (IV): The ideal gas law, which describes the state of a hypothetical ideal gas, is mathematically formulated as:
\[ P \cdot V = n \cdot R \cdot T \]
where $P$ is pressure, $V$ is volume, $n$ is the number of moles, $R$ is the universal gas constant, and $T$ is temperature.
- (C) pH $\rightarrow$ Sorenson (I): S.P.L. Sørensen introduced the pH scale in 1909 to express hydrogen ion concentration ($-\log[H^+]$) in solutions.
- (D) pF $\rightarrow$ Schofield (II): R.K. Schofield introduced the "pF" scale in 1935 to express soil water suction, where pF is the logarithm of the free energy of soil water expressed as a head of water in centimeters.
This matching sequence gives: (A) - (III), (B) - (IV), (C) - (I), (D) - (II).
This matches Option (D).

Step 4: Final Answer:
The correct matching sequence is (A) - (III), (B) - (IV), (C) - (I), (D) - (II).