Question

Carbon tetrachloride, once widely used in fire extinguishers andas a dry cleaning fluid, has been found to cause liver damage tothose exposed to its vapors over long periods of time. What is theboiling point of a solution prepared by dissolving 375 g of sulfur(S8, MW = 256.5g/mol) in 1250 g of CCl4?Kb = 5.05°C/m, boiling point ofpure CCl4 = 76.7°C)?A.70.8°C B.75.2°CC.78.2°CD.82.6°CE.>85°C

Answer 1

Answer:option D= 82.6°C

Explanation:

Step 1: determine the molality

Molality = moles of solute/ kg of solvent.

(Recall: number of moles= mass / molar mass).

Therefore, 375/256.5 g/mol = 1.4620 mole.

Substituting into the molality equation we have,

1.4620/ 0.1250kg = 11.696.

∆T(b) = k(b) × molality

∆T(b) = 82.6°C