Question

What is the molality of a solution prepared by dissolving 86.9 g of diethyl ether

Answer 1

Question: What is the molality of a solution prepared by dissolving 86.9 g of diethyl ether, C4H10O, in 425 g of benzene, C6H6?

Answer: 2.76 mol/kg

Explanation:

Formula of morality is moles of solute divided by the mass of the solvent.

Molality = moles of solute/ mass of solvents (kg)

Mass of solvent is 425g = 0.452kg

Moles = mass / molar mass

Mass of diethyl ester = 86.9g

Molar mass of diethyl ether (C4H10O) = 12*4 + 1*10+ 16

= 48+ 10 + 16

= 74g/mol.

So moles of diethyl ester = 86.9 g / 74 g/mol= 1.17 mol

molality = 1.17mol/0.425kg = 2. 75 mol/kg

Answer is 2. 76 mol approximately.