Calculate the mass of urea `(NH_(2)CONH_(2))` required in making `2.5 kg `of `0.25 `molal aqueous solution.

Explanation

To calculate the mass of urea (NH₂CONH₂) required to make a 2.5 kg of 0.25 molal aqueous solution, follow these steps:

### Step 1: Understand the definition of molality
Molality (m) is defined as the number of moles of solute per kilogram of solvent. The formula is:
\[ m = \frac{\text{moles of solute}}{\text{mass of solvent (kg)}} \]

### Step 2: Identify the given values
- Molality (m) = 0.25 molal
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