Question

Match the following in Ellingham diagram:

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

Hint:

In Ellingham diagrams, slope directly represents entropy change.

Answer 1

The Correct Option is B

Concept: In Ellingham diagram: \[ \Delta G^\circ = \Delta H^\circ - T\Delta S^\circ \] So slope of line is: \[ \frac{d(\Delta G^\circ)}{dT} = -\Delta S^\circ \]

Step 1: Match A.
Slope equals: \[ -\Delta S^\circ \Rightarrow \text{A-I} \]

Step 2: Large negative slope.
Large negative slope means: \[ \Delta S^\circ \text{ is large positive} \Rightarrow \text{B-II} \]

Step 3: Nearly horizontal line.
Slope ≈ 0: \[ \Delta S^\circ \approx 0 \Rightarrow C-IV \]

Step 4: Parallel lines.
Parallel means same slope: \[ \Delta S^\circ \text{ similar} \Rightarrow D-III \] Final Answer: \[ A-I,\; B-II,\; C-IV,\; D-III \]