For the precipitation of AgCl by `Ag^(+)` ions and HCl

Options

A. `Delta H = 0`
B. `Delta G = 0`
C. `Delta G = -ve`
D. `Delta H = Delta G`

Explanation

To solve the question regarding the precipitation of AgCl by Ag⁺ ions and HCl, we will analyze the thermodynamic parameters involved in the reaction.

### Step-by-Step Solution:

1. **Understanding the Reaction**:
The reaction for the precipitation of silver chloride (AgCl) can be represented as:
\[ \text{Ag}^+ (aq) + \text{Cl}^- (aq) \rightarrow \text{AgCl} (s) \]
This is a spontaneous reaction that leads to the formation of a solid precipitate (AgCl).

2. **Gibbs Free Energy Equation**:
The spontaneity of a reaction can be determined using the Gibbs free energy (ΔG) equation:
\[ \Delta G = \Delta H - T \Delta S \]
where:
- ΔG = change in Gibbs free energy
- ΔH = change in enthalpy
- T = temperature in Kelvin
- ΔS = change in entropy

3. **Analyzing the Options**:
We need to evaluate the given options based on the criteria for spontaneity (ΔG < 0).

- **Option A: ΔH = 0**
If ΔH is 0, then ΔG can only be negative if ΔS is also negative, which would make the reaction non-spontaneous. Therefore, this option is incorrect.

- **Option B: ΔG = 0**
If ΔG is 0, the reaction is at equilibrium and not spontaneous. Therefore, this option is also incorrect.

- **Option C: ΔG < 0**
This indicates that the reaction is spontaneous. For a spontaneous reaction, ΔG must be negative. Therefore, this option is correct.

- **Option D: ΔH = ΔG**
If ΔH equals ΔG, we cannot determine the spontaneity without knowing ΔS. This option does not provide a clear conclusion about spontaneity. Therefore, this option is incorrect.

4. **Conclusion**:
Based on the analysis, the correct option that indicates the spontaneity of the precipitation of AgCl is:
\[ \text{Option C: } \Delta G < 0 \]