The osmotic pressure of a 0.0750 M KCl solution at 25.0°C is 3.28 atm. What is the true van't Hoff factor of this ionic compound?

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The van't Hoff factor (i) can be calculated using the formula for osmotic pressure: $\pi = iMRT$, where $\pi$ is the osmotic pressure, $M$ is the molarity, $R$ is the gas constant (0.0821 L·atm/K·mol), and $T$ is the temperature in Kelvin. Given $\pi = 3.28$ atm and $M = 0.0750$ M at $T = 25.0°C = 298K$, we can solve for $i$:$$3.28 = i \times 0.0750 \times 0.0821 \times 298$$Solving for $i$ gives approximately 1.79, indicating the true van't Hoff factor for KCl in this solution.

The Osmotic Pressure of a 0