Which term describes the change in boiling point that a liquid experiences when solute is dissolved in it?

Which term describes the change in boiling point that a liquid experiences when solute is dissolved in it?

• A. Boiling Point Elevation
• B. Freezing Point Depression
• C. Osmosis
• D. Osmotic Pressure

Answer: (A)

When you dissolve a nonvolatile solute in a liquid, the boiling point rises. This happens because the dissolved particles lower the solvent’s vapor pressure at a given temperature, so you must heat the liquid more to reach a vapor pressure equal to the surrounding pressure. The amount the boiling point increases is described by boiling point elevation, which depends on how many solute particles are present (the van’t Hoff factor), the solvent’s ebullioscopic constant, and the molality of the solution. The other terms describe different phenomena: freezing point depression lowers the freezing point, while osmosis and osmotic pressure relate to water movement across membranes and the pressure needed to counter that movement, not to boiling point.

When you dissolve a nonvolatile solute in a liquid, the boiling point rises. This happens because the dissolved particles lower the solvent’s vapor pressure at a given temperature, so you must heat the liquid more to reach a vapor pressure equal to the surrounding pressure. The amount the boiling point increases is described by boiling point elevation, which depends on how many solute particles are present (the van’t Hoff factor), the solvent’s ebullioscopic constant, and the molality of the solution. The other terms describe different phenomena: freezing point depression lowers the freezing point, while osmosis and osmotic pressure relate to water movement across membranes and the pressure needed to counter that movement, not to boiling point.