Question

The normal boiling point of a certain liquid X is 141.70 °C, but when 68.1 g of barium hydroxide (Ba(OH)) are dissolved in 750. g of X the solution boils at 142.5C instead. Use this information to calculate the molal boiling point elevation constant

Answer 1

Answer:

Explanation:

Normal boiling point = 141.7°C

Elevated boiling point = 142.5°C

Elevation of boiling point Δt = 0.8°C

Formula for elevation of boiling point is as follows .

Δt = 1000 x Kb x w / (MW )

where w is weight of solute , M is molecular weight of solute , W is weight of solvent in grams,  Kb is molal boiling point elevation constant .

Mol weight of barium hydroxide = 171 .

.8 = 1000 x Kb x 68.1 / (171 x 750 )

Kb = 1.5°C / m