Range the following electrolytes in the increasing order of coagulating power for the coagulation of `As_2S_3` sol
(I) `MgSO_4`
(II) `BaCl_2`
(III) `NaCl`

Options

A. `III gt I gtII`
B. `IgtIIgtIII`
C. `IIIgtIIgtI`
D. `IgtIIIgtII`

Answer

To determine the increasing order of coagulating power for the coagulation of `As_2S_3` sol among the given electrolytes (`MgSO_4`, `BaCl_2`, and `NaCl`), we need to understand the relationship between coagulating power and coagulation value.

### Step-by-Step Solution:

1. **Understanding Coagulating Power**:
- Coagulating power is inversely proportional to the coagulation value. This means that the higher the coagulation value, the lower the coagulating power.

2. **Coagulation Values of the Electrolytes**:
- We need to know the coagulation values for the given electrolytes:
- `MgSO_4` has the lowest coagulation value.
- `BaCl_2` has a moderate coagulation value.
- `NaCl` has the highest coagulation value.

3. **Ranking the Coagulation Values**:
- Based on the coagulation values:
- `MgSO_4` < `BaCl_2` < `NaCl`
- This means:
- `MgSO_4` has the highest coagulating power (because it has the lowest coagulation value).
- `BaCl_2` is in the middle.
- `NaCl` has the lowest coagulating power (because it has the highest coagulation value).

4. **Increasing Order of Coagulating Power**:
- Since we are asked for the increasing order of coagulating power, we arrange them from the lowest coagulating power to the highest:
- `NaCl` < `BaCl_2` < `MgSO_4`

### Final Answer:
The increasing order of coagulating power for the coagulation of `As_2S_3` sol is:
**`NaCl` < `BaCl_2` < `MgSO_4`**