Which of the following has the highest and lowest cogulating power? `(Al^(+3),Na^(+),Mg^(+2),Ba^(+2)`) ?

Options

A. `Al^(+3) , Na^(+`
B. `Na^(+), Al^(+3)`
C. `Ba^(+2), Al^(+3)`
D. They have same flocculation value

Answer

To determine which ion has the highest and lowest coagulating power among \( Al^{3+}, Na^{+}, Mg^{2+}, \) and \( Ba^{2+} \), we can use Hardy's law of coagulation. According to this law, the coagulating power of an ion is directly proportional to its valency (or charge).

### Step-by-Step Solution:

1. **Identify the charges of the ions:**
- \( Al^{3+} \) has a charge of +3.
- \( Na^{+} \) has a charge of +1.
- \( Mg^{2+} \) has a charge of +2.
- \( Ba^{2+} \) has a charge of +2.

2. **Rank the ions based on their charges:**
- The charges are as follows:
- \( Al^{3+} \): +3
- \( Mg^{2+} \): +2
- \( Ba^{2+} \): +2
- \( Na^{+} \): +1

3. **Determine the highest coagulating power:**
- Since the coagulating power is directly proportional to the charge, the ion with the highest charge will have the highest coagulating power.
- Here, \( Al^{3+} \) has the highest charge of +3, so it has the highest coagulating power.

4. **Determine the lowest coagulating power:**
- The ion with the lowest charge will have the lowest coagulating power.
- Here, \( Na^{+} \) has the lowest charge of +1, so it has the lowest coagulating power.

5. **Conclusion:**
- The ion with the highest coagulating power is \( Al^{3+} \).
- The ion with the lowest coagulating power is \( Na^{+} \).

### Final Answer:
- Highest coagulating power: \( Al^{3+} \)
- Lowest coagulating power: \( Na^{+} \)