What are isotonic solutions ? Give one example .

Explanation

### Step-by-Step Solution:

1. **Definition of Isotonic Solutions**:
Isotonic solutions are defined as solutions that have the same osmotic pressure. The term "iso" means equal, indicating that the osmotic pressures of the solutions are equal.

2. **Understanding Osmotic Pressure**:
Osmotic pressure is the pressure required to prevent the flow of solvent molecules across a semi-permeable membrane. In isotonic solutions, since the osmotic pressures are equal, there is no net movement of solvent molecules between the two solutions.

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