A semi molar solution is the one, which contains

Options

A. One mole solute in 2 litres
B. 2 moles solute in 2 litres
C. 0.1 mole solute in 1 litre
D. 0.2 moles solute in 2 litres

Explanation

To solve the question regarding what a semi-molar solution is, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Term "Semi":**
- The prefix "semi" means "half." Therefore, when we refer to a "semi-molar" solution, we are indicating that the molarity is half of a standard molar solution.

2. **Defining Molarity:**
- Molarity (M) is defined as the number of moles of solute per liter of solution. A 1 molar (1 M) solution contains 1 mole of solute in 1 liter of solution.

3. **Calculating for Semi-Molar Solution:**
- Since "semi" means half, a semi-molar solution would contain half a mole of solute in 1 liter of solution. Thus, a semi-molar solution is 0.5 M.

4. **Relating to Volume:**
- If we consider a scenario where we have 1 mole of solute, to maintain the semi-molar concentration (0.5 M), we would need to dissolve that 1 mole of solute in 2 liters of solution. This is because:
- Molarity = Moles of solute / Volume of solution (in liters)
- Rearranging gives Volume = Moles of solute / Molarity
- For 1 mole of solute at 0.5 M: Volume = 1 mole / 0.5 M = 2 liters.

5. **Conclusion:**
- Therefore, a semi-molar solution is defined as containing 1 mole of solute in 2 liters of solution.

### Final Answer:
A semi-molar solution is one that contains **1 mole of solute in 2 liters of solution**.