Question

Molal elevation constant is also known as:

• A. Ebullioscopic constant
• B. Gas constant
• C. Henry’s constant
• D. Cryoscopic constant

Answer 1

The Correct Option is A

In solution chemistry, the molal elevation constant, or ebullioscopic constant, is crucial for understanding colligative properties. These properties are influenced by the number of solute particles, not their chemical identity. Boiling point elevation is one such property, observed when a solute dissolves in a solvent.

Adding a non-volatile solute to a solvent raises the solution's boiling point compared to the pure solvent. This occurs because the solute lowers the solvent's vapor pressure, necessitating a higher temperature to achieve boiling. The boiling point change, ΔT_b, is calculated using:

ΔT_b = K_b × m

Where:

• ΔT_b represents the boiling point elevation.
• K_b is the molal elevation constant, also termed the ebullioscopic constant.
• m denotes the molality of the solution (moles of solute per kilogram of solvent).

The term "ebullioscopic constant" derives from the Latin "ebullire" (to boil) and indicates the extent of boiling point increase per molal concentration of the solute.

Based on the provided options, the correct term is: Ebullioscopic constant