Question

What is the molarity of a solution that is prepared by adding 57.1 g of toluene (c 7 ​ h 8 ​ ) (density = 0.867 g/ml) to a 250 ml volumetric flask, and then filling to the mark with benzene (c 6 ​ h 6 ​ ) (density = 0.876 g/ml)?

Answer 1

Answer:

2.48 mol/L.

Explanation:

• The molarity of the solution can be expressed as the number of moles of solute in 1.0 liter of the solution, (M = n / V).

• It is also can be calculated from the relation:

M = (mass / molar mass) solute x (1000 / V of solution)

The solute is toluene and the solvent is benzene.

mass of toluene (solute) = 57.1 g,

molar mass of toluene (solute) = 92.14 g/mol.

volume of the solution = 250 ml.

∴ M =  (mass / molar mass) solute x (1000 / V of solution) = [(57.1 g / 92.14 g/mol) x (1000 / 250 ml)] = 2.48 mol/L.