Parke's process of desilverization of lead depends upon

Options

A. Partition coefficient of silver between molten zinc/molten lead having a high value
B. Partition coefficient of silver between molten zinc/molten lead gaving a low value
C. Crystallizing out of pure lead while the silver-lead eutectic which has a lower melting point is left behind in liquid form
D. Chemical combination of zinc and silver which precipitates out easily

Answer

To answer the question regarding Parke's process of desilverization of lead, we can break down the explanation step by step.

### Step-by-Step Solution:

1. **Understanding Parke's Process**:
Parke's process is a method used to separate silver from lead. It is particularly useful when lead ores contain a significant amount of silver.

2. **Principle of the Process**:
The process relies on the difference in solubility of lead and silver in a mixture of lead and zinc. When lead is alloyed with silver, the silver can be separated by adding zinc.

3. **Formation of Zinc Silver Alloy**:
When zinc is added to the molten lead-silver alloy, it reacts with silver to form a zinc-silver alloy. This alloy is less dense than lead and can be easily removed from the mixture.

4. **Separation of Lead and Silver**:
The lead remains in the molten state while the zinc-silver alloy solidifies and can be skimmed off the surface. This effectively removes the silver from the lead.

5. **Final Steps**:
After the zinc-silver alloy is removed, the remaining lead is purified and can be used for various applications. The zinc can be recovered by heating the alloy to separate the silver from the zinc.

### Conclusion:
Thus, Parke's process of desilverization of lead depends upon the selective solubility of silver in zinc, allowing for the effective separation of silver from lead.