1200gm aqueous solution contains 200gm calcium bromide
`(CaBr_(2))`. Calculate molality of solution

Answer

To calculate the molality of the solution, we can follow these steps:

### Step 1: Identify the mass of the solution and the solute
We are given that the total mass of the aqueous solution is 1200 grams, and the mass of the solute (calcium bromide, CaBr₂) is 200 grams.

### Step 2: Calculate the mass of the solvent
To find the mass of the solvent, we subtract the mass of the solute from the total mass of the solution.

\[ \text{Mass of solvent} = \text{Mass of solution} - \text{Mass of solute} \]
\[ \text{Mass of solvent} = 1200 \, \text{g} - 200 \, \text{g} = 1000 \, \text{g} \]

### Step 3: Convert the mass of the solvent to kilograms
Since molality is defined in terms of kilograms of solvent, we convert the mass of the solvent from grams to kilograms.

\[ \text{Mass of solvent in kg} = \frac{1000 \, \text{g}}{1000} = 1 \, \text{kg} \]

### Step 4: Calculate the number of moles of the solute
To find the number of moles of calcium bromide (CaBr₂), we need to use its molar mass. The molar mass of CaBr₂ can be calculated as follows:

- Molar mass of Ca = 40 g/mol
- Molar mass of Br = 80 g/mol (since there are 2 bromine atoms, we multiply by 2)

\[ \text{Molar mass of CaBr₂} = 40 + (2 \times 80) = 40 + 160 = 200 \, \text{g/mol} \]

Now, we can calculate the number of moles of CaBr₂:

\[ \text{Number of moles of CaBr₂} = \frac{\text{Mass of solute}}{\text{Molar mass of solute}} = \frac{200 \, \text{g}}{200 \, \text{g/mol}} = 1 \, \text{mol} \]

### Step 5: Calculate the molality of the solution
Now that we have the number of moles of the solute and the mass of the solvent in kilograms, we can calculate the molality (m) of the solution using the formula:

\[ \text{Molality (m)} = \frac{\text{Number of moles of solute}}{\text{Mass of solvent in kg}} = \frac{1 \, \text{mol}}{1 \, \text{kg}} = 1 \, \text{molal} \]

### Final Answer
The molality of the solution is **1 molal**.

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