Practicing Success
The osmotic pressure at 17°C of an aqueous solution containing 1.75 g of sucrose per 150 mL solution is: |
0.08 atm 8.1 atm 0.81 9. 1 atm |
0.81 |
The correct answer is option 3. 0.81. To find the osmotic pressure (\(\pi\)) of the solution, we can use the formula: \(\pi = i \cdot M \cdot R \cdot T \) Where: \( i \) is the van 't Hoff factor (which is 1 for sucrose), \( M \) is the molarity of the solution, \( R \) is the ideal gas constant (0.08206 L atm K\(^{-1}\) mol\(^{-1}\)), \( T \) is the temperature in Kelvin. First, let's find the molarity (\( M \)) of the solution using the given data: Given: Mass of sucrose (\( \text{C}_{12}\text{H}_{22}\text{O}_{11} \)) = 1.75 g, Volume of solution = 150 mL, Molar mass of sucrose = 342 g/mol. \(\text{moles of sucrose} = \frac{\text{mass of sucrose}}{\text{molar mass of sucrose}} \) \(\text{moles of sucrose} = \frac{1.75 \, \text{g}}{342 \, \text{g/mol}} = 0.005116 \, \text{mol} \) \(\text{Volume of solution} = 150 \, \text{mL} = 0.150 \, \text{L} \) \(M = \frac{0.005116 \, \text{mol}}{0.150 \, \text{L}} = 0.034107 \, \text{M} \) \(\pi = (1) \times (0.034107 \, \text{M}) \times (0.08206 \, \text{L atm K}^{-1} \text{mol}^{-1}) \times (290.15 \, \text{K}) \) Therefore, the osmotic pressure of the solution is approximately 0.83 atm. None of the given options exactly match the calculated value, but the closest option is 0.81 atm. |