A 275 mg sample of a nonelectrolyte compound was dissolved in water to produce 10.0 mL of a solution at 25 $\degree$C.The osmotic pressure of this solution was measured and found to be 3.67 atm.What is the molar mass of this compound?

Question

Quizplus · Accepted Answer

The molar mass of the compound can be calculated using the formula for osmotic pressure: $\pi = \frac{n}{V}RT$, where $\pi$ is the osmotic pressure, $n$ is the number of moles of solute, $V$ is the volume of the solution in liters, $R$ is the ideal gas constant (0.0821 L·atm/(K·mol)), and $T$ is the temperature in Kelvin. First, convert the temperature to Kelvin (25°C + 273.15 = 298.15 K) and the volume to liters (10.0 mL = 0.010 L). The number of moles $n$ can be found by rearranging the formula to $n = \frac{\pi V}{RT}$. Substituting the given values gives $n = \frac{3.67 atm \times 0.010 L}{0.0821 L·atm/(K·mol) \times 298.15 K}$, which calculates to approximately 0.0015 moles. The molar mass (M) is the mass of the compound divided by the number of moles, so $M = \frac{0.275 g}{0.0015 mol} \approx 183 g/mol$.

A 275 Mg Sample of a Nonelectrolyte Compound Was Dissolved °\degree°

A 275 Mg Sample of a Nonelectrolyte Compound Was Dissolved $\degree$