The van't Hoff factor i is defined as:

• A. The number of moles of solute particles per liter
• B. The number of particles a solute yields in solution
• C. The ratio of solvent to solute
• D. The ionic charge of the solute

Answer: (B)

The van't Hoff factor i describes how many particles a dissolved solute yields in solution. This count matters because colligative properties—like boiling-point elevation, freezing-point depression, and osmotic pressure—depend on the number of particles in solution, not on their identity. For a non-electrolyte, the solute stays as one particle per formula unit, so i is about 1. For electrolytes, dissociation into ions increases the number of particles; a 1:1 salt splits into two ions, giving i near 2 (though real solutions may show slightly less due to incomplete dissociation or ion pairing). Since i is a count of particles produced, it is not the molarity of solute particles, not a solvent-to-solute ratio, and not the ionic charge. The correct description is that i is the number of particles a solute yields in solution.