The capacity of an ion to coagulate a colloidal solution depends on

Options

A. Its shape
B. The amount of its charge
C. The sign of the charge
D. Both, the amount and the sign of the charge

Answer

To determine the capacity of an ion to coagulate a colloidal solution, we need to analyze the factors that influence this process.

### Step-by-Step Solution:

1. **Understanding Coagulation**: Coagulation refers to the process where colloidal particles aggregate to form larger particles, leading to the separation of the colloid. This process is influenced by the presence of ions in the solution.

2. **Role of Charge**: The charge of the ions plays a crucial role in coagulation. Colloidal particles typically carry a charge (either positive or negative) that keeps them dispersed in the solution. When oppositely charged ions are introduced, they neutralize the charge on the colloidal particles, leading to coagulation.

3. **Amount of Charge**: The effectiveness of an ion in coagulating a colloidal solution also depends on the amount of charge it carries. Ions with a higher charge can neutralize the colloidal particles more effectively than those with a lower charge. Thus, the amount of charge is a significant factor.

4. **Sign of Charge**: The sign of the charge is equally important. For coagulation to occur, the ion must have an opposite charge to that of the colloidal particles. For example, if the colloidal particles are negatively charged, positively charged ions will promote coagulation.

5. **Conclusion**: Therefore, the capacity of an ion to coagulate a colloidal solution depends on both the amount of its charge and the sign of the charge.

### Final Answer:
The capacity of an ion to coagulate a colloidal solution depends on **both the amount and the sign of the charge**.