Number of moles of solute dissolved in 1000 g. of the solvent is called

Options

A. Molarity
B. Molality
C. Formality
D. Normality

Explanation

To solve the question "Number of moles of solute dissolved in 1000 g of the solvent is called," we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept**: We need to identify the term that describes the concentration of a solute in a solvent, specifically in relation to the mass of the solvent.

2. **Identify the Mass of Solvent**: The question specifies that the mass of the solvent is 1000 grams. This is equivalent to 1 kilogram (since 1000 g = 1 kg).

3. **Define the Term**: The concentration term that describes the number of moles of solute per kilogram of solvent is known as "molality."

4. **Mathematical Expression**: Molality (m) is mathematically expressed as:
\[ m = \frac{n}{W} \]
where:
- \( m \) = molality
- \( n \) = number of moles of solute
- \( W \) = weight of the solvent in kilograms (kg)

5. **Conclusion**: Therefore, the answer to the question is that the number of moles of solute dissolved in 1000 g of the solvent is called "molality."

### Final Answer:
The number of moles of solute dissolved in 1000 g of the solvent is called **molality**.

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