Given below are two statements related to Ellingham diagram:
Statement-I : Ellingham diagrams can be constructed for formation of oxides, sulfides and halides of metals.
Statement-II : It consists of plots of vs T for formation of oxides of elements.
In the light of the above statements, choose the most appropriate answer from the options given below:
Statement-I : Ellingham diagrams can be constructed for formation of oxides, sulfides and halides of metals.
Statement-II : It consists of plots of vs T for formation of oxides of elements.
In the light of the above statements, choose the most appropriate answer from the options given below:
- (A)Both Statement I and Statement II are incorrect
- (B)Statement I is incorrect but Statement II is correct
- (C)Both Statement I and Statement II are correct
- (D)Statement I is correct but Statement II is incorrect✓ Correct
Answer: (D)
Solution
An Ellingham diagram is a plot of the standard free energy of formation of a compound against temperature, and such diagrams can be constructed not only for oxides but also for the sulfides and halides of metals, which makes Statement I correct. The quantity plotted on the vertical axis is the standard Gibbs free energy of formation, , and not the standard enthalpy of formation, ; it is the sign of that decides whether a reduction becomes feasible at a given temperature. Statement II, which names the enthalpy of formation, is therefore incorrect, so Statement I is correct but Statement II is incorrect.
JEE Main · 2023 · 13 Apr 2023 · Shift 2 · Single correct option