Antifreeze is often about 50.% ethylene glycol, C₂H6O2, in water. What is the molality of the solution?

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### Determining the Molality of an Antifreeze Solution

Antifreeze is often about 50.0% ethylene glycol (C₂H₆O₂) in water. To find the molality of this solution, we use the provided information and the following steps:

#### Information Given:
- Molecular Mass (Molar Mass) of Ethylene Glycol (C₂H₆O₂): 62.068 g/mol
- Composition of Antifreeze: 50.0% by weight of ethylene glycol in water.

#### What We Need to Find:
- Molality (m) of the solution.

### Step-by-Step Calculation:

1. **Understanding Molality:**
   Molality (m) is defined as the number of moles of solute (in this case, ethylene glycol) per kilogram of solvent (water). The formula is:

   \[
   m = \frac{\text{moles of solute}}{\text{kilograms of solvent}}
   \]

2. **Calculating Moles of Ethylene Glycol:**
   Let’s assume we have 100 g of antifreeze solution (since it's easy to work with percentage composition).

   - Ethylene glycol is 50.0% by weight in the solution.
   - Therefore, in 100 g of solution, we have 50 g of ethylene glycol.
   
   Now, convert grams to moles using the given molar mass:

   \[
   \text{moles of } C_2H_6O_2 = \frac{50 \, \text{g}}{62.068 \, \text{g/mol}} = 0.805 \, \text{mol}
   \]

3. **Calculating Mass of Water:**
   - Since 50 g of the solution is ethylene glycol, the remaining 50 g is water.
   - Convert grams to kilograms:
   
   \[
   \text{mass of water} = 50 \, \text{g} = 0.050 \, \text{kg}
   \]

4. **Calculating Molality:**

   \[
   m = \frac{0.805 \, \text{mol}}{0.050 \, \text{kg}} = 16.1 \, \text{mol/kg}
   \]

### Solution:

The molality of the ethylene glycol
Transcribed Image Text:### Determining the Molality of an Antifreeze Solution Antifreeze is often about 50.0% ethylene glycol (C₂H₆O₂) in water. To find the molality of this solution, we use the provided information and the following steps: #### Information Given: - Molecular Mass (Molar Mass) of Ethylene Glycol (C₂H₆O₂): 62.068 g/mol - Composition of Antifreeze: 50.0% by weight of ethylene glycol in water. #### What We Need to Find: - Molality (m) of the solution. ### Step-by-Step Calculation: 1. **Understanding Molality:** Molality (m) is defined as the number of moles of solute (in this case, ethylene glycol) per kilogram of solvent (water). The formula is: \[ m = \frac{\text{moles of solute}}{\text{kilograms of solvent}} \] 2. **Calculating Moles of Ethylene Glycol:** Let’s assume we have 100 g of antifreeze solution (since it's easy to work with percentage composition). - Ethylene glycol is 50.0% by weight in the solution. - Therefore, in 100 g of solution, we have 50 g of ethylene glycol. Now, convert grams to moles using the given molar mass: \[ \text{moles of } C_2H_6O_2 = \frac{50 \, \text{g}}{62.068 \, \text{g/mol}} = 0.805 \, \text{mol} \] 3. **Calculating Mass of Water:** - Since 50 g of the solution is ethylene glycol, the remaining 50 g is water. - Convert grams to kilograms: \[ \text{mass of water} = 50 \, \text{g} = 0.050 \, \text{kg} \] 4. **Calculating Molality:** \[ m = \frac{0.805 \, \text{mol}}{0.050 \, \text{kg}} = 16.1 \, \text{mol/kg} \] ### Solution: The molality of the ethylene glycol
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