Molarity, Molality & Mole Fraction Calculations for Glycerol-Water Solution

[magma_saber]

Homework Statement

A solution containing equal masses of glycerol, C3H8O3, and water has a density of
1.10 g/mL. Calculate the (a) molarity; (b) mole fraction of glycerol; (c) molality of
the solution.

Homework Equations

M=moles of solute/liters of solution
mole fraction = n1/n(total)
molality = mole of solute/kg of solvent

The Attempt at a Solution

How do you calculate the moles? i think i got the liters of solution by doing this: molar mass of gycerol/density. then convert the mL to L.

 

[Borek]

You are told "equal masses". That means every substance mass is a third of the solution mass. Start with 1 liter.

 

[Blueshift5]

To calculate the moles of glycerol, you would use the given mass of glycerol and its molar mass to determine the number of moles. The molar mass of glycerol is 92.09 g/mol, so if the solution contains equal masses of glycerol and water, then the mass of glycerol would be half of the solution's total mass. You can then use the molarity equation (M=moles of solute/liters of solution) to calculate the molarity of the solution.

To calculate the mole fraction of glycerol, you would use the number of moles of glycerol and the total number of moles (which can be calculated using the molarity) in the mole fraction equation (mole fraction = n1/n(total)).

To calculate the molality, you would use the number of moles of glycerol and the mass of the solvent (water) in kilograms. You can then use the molality equation (molality = moles of solute/kg of solvent) to calculate the molality of the solution.

Remember to convert all units to the appropriate units (e.g. convert mL to L, g to kg) before plugging them into the equations.