For the coagulation of 100ml of a positive sol 10ml of 1M sodium chloride is required. Calculate the flocculation value.

Answer

To calculate the flocculation value for the coagulation of a positive sol using sodium chloride, we can follow these steps:

### Step-by-step Solution:

1. **Understanding Flocculation Value**:
- The flocculation value is defined as the number of millimoles of electrolyte required to coagulate 1 liter of colloid.

2. **Given Data**:
- Volume of positive sol (colloid) = 100 ml
- Volume of sodium chloride solution required for coagulation = 10 ml
- Concentration of sodium chloride solution = 1 M (1 mole per liter)

3. **Calculating Moles of Sodium Chloride Used**:
- Since the solution is 1 M, this means that 1 liter (1000 ml) of this solution contains 1 mole of NaCl.
- Therefore, the number of moles in 10 ml of 1 M NaCl can be calculated as follows:
\[ \text{Moles of NaCl} = \text{Concentration (M)} \times \text{Volume (L)} = 1 \, \text{mol/L} \times \frac{10 \, \text{ml}}{1000 \, \text{ml}} = 0.01 \, \text{moles} \]

4. **Converting Moles to Millimoles**:
- To convert moles to millimoles, we multiply by 1000:
\[ \text{Millimoles of NaCl} = 0.01 \, \text{moles} \times 1000 = 10 \, \text{millimoles} \]

5. **Calculating Flocculation Value**:
- The 10 millimoles of NaCl are required to coagulate 100 ml of the positive sol.
- To find out how many millimoles are required to coagulate 1 liter (1000 ml) of the positive sol, we can set up a proportion:
\[ \text{Flocculation Value} = \frac{10 \, \text{millimoles}}{100 \, \text{ml}} \times 1000 \, \text{ml} = 100 \, \text{millimoles} \]

### Final Answer:
The flocculation value is **100 millimoles**.

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