For the MCAT, which van't Hoff factor value should be used for NaCl?

The van't Hoff factor (i) represents the number of particles into which a solute dissociates in solution. For sodium chloride (NaCl), it dissociates into two ions when it dissolves in water: one sodium ion (Na⁺) and one chloride ion (Cl⁻). Therefore, the correct van't Hoff factor for NaCl is 2, indicating that each formula unit of NaCl produces two particles in solution.

This value is significant in various colligative properties calculations, such as boiling point elevation and freezing point depression, where the effects depend on the total concentration of particles in solution rather than the concentration of the solute itself. Understanding the van't Hoff factor is crucial for predicting how solutes will behave in a solution, particularly in scenarios involving ionic compounds like NaCl.