The temperature at which 10% aqueous solution of glucose will show the osmotic pressure of 14 atm is: |
34 K 307.3°C 307.3 K 34°C |
307.3 K |
The correct answer is option 3. 307.3 K. To find the temperature at which a 10% aqueous solution of glucose will show an osmotic pressure of 14 atm, we can use the formula for osmotic pressure: \(\Pi = iMRT \) where: \(\Pi\) is the osmotic pressure, \(i\) is the van 't Hoff factor (for glucose, which does not dissociate in solution, \(i = 1\)), \(M\) is the molarity of the solution, \(R\) is the universal gas constant (0.0821 L·atm·K⁻¹·mol⁻¹), \(T\) is the temperature in Kelvin. First, we need to determine the molarity (\(M\)) of the glucose solution. A 10% by weight aqueous solution of glucose means there are 10 grams of glucose in 100 grams of solution. The molar mass of glucose \((C_6H_{12}O_{6})\) is approximately 180 g/mol. Number of moles of glucose \( = \frac{10 \text{ g}}{180 \text{ g/mol}} \approx 0.0556 \text{ mol} \). The density of water is approximately 1 g/mL, so 100 grams of the solution is roughly 100 mL or 0.1 L (since the solution is dilute, we can assume the volume is close to that of water). Molarity \(M = \frac{\text{moles of solute}}{\text{volume of solution in liters}} = \frac{0.0556 \text{ mol}}{0.1 \text{ L}} = 0.556 \text{ M} \). \( \Pi = iMRT \) Given: \(\Pi = 14 \text{ atm}\), \(i = 1\), \(M = 0.556 \text{ M}\), \(R = 0.0821 \text{ L·atm·K⁻¹·mol⁻¹}\). Rearrange the formula to solve for \(T\): \(T = \frac{\Pi}{iMR} \) Substitute the known values: \(T = \frac{14 \text{ atm}}{(1)(0.556 \text{ mol/L})(0.0821 \text{ L atm K}^{-1}mol^{-1})} \) \(T = \frac{14}{0.04566} \) \(T \approx 306.8 \text{ K} \) The closest answer to this value is: 307.3 K. |