Which of the following statements, about the advantage of roasting of sulphide ore before reduction is not true gt

Options

A. The `DeltaG_(f)^(@)` of the sulphide is greater than those for `CS_(2)` and `H_(2)S`
B. The `DeltaG_(F)^(@)` is negative for roasting of sulphide ore to oxide.
C. Roasting of the sulphide to the oxide is thermodynamically feasible.
D. Carbon and hydrogen are suitable reducing agents for metal sulphides.

Explanation

To determine which statement about the advantages of roasting of sulphide ore before reduction is not true, we can analyze the given statements step by step.

### Step-by-Step Solution:

1. **Understanding Roasting of Sulphide Ores**:
- Roasting is a process where sulphide ores are heated in the presence of oxygen. This process converts the sulphides into oxides.

2. **Analyzing the Statements**:
- **Statement 1**: "Delta GF of sulphide is greater than CS2 and H2S."
- This statement is true. The standard free energy of formation (Delta GF) for most sulphide ores is indeed greater than that of carbon disulfide (CS2) and hydrogen sulfide (H2S).

- **Statement 2**: "Standard energy formation is negative for roasting of sulphide ore to oxide."
- This statement is also true. The roasting process is exothermic, meaning it releases energy, and thus the standard free energy of formation is negative.

- **Statement 3**: "Roasting of the sulphide to oxide is thermodynamically feasible."
- This statement is true. The process is thermodynamically favorable due to the lower standard free energy of formation of oxides compared to that of sulphur dioxide (SO2).

- **Statement 4**: "Carbon and hydrogen are suitable reducing agents for metal sulphides."
- This statement is incorrect. Carbon and hydrogen are not suitable reducing agents for metal sulphides because the standard free energy of formation of metal sulphides is greater than that of carbon and hydrogen. Therefore, they cannot effectively reduce metal sulphides to metals.

3. **Conclusion**:
- The statement that is not true is: "Carbon and hydrogen are suitable reducing agents for metal sulphides."

### Final Answer:
The incorrect statement about the advantages of roasting of sulphide ore before reduction is: **"Carbon and hydrogen are suitable reducing agents for metal sulphides."**