Determine the mass of the solid given its density is 2.50 g/mL.

Question

A liquid solvent is added to a flask containing an insoluble solid. The total volume of the solid and liquid together is 86.0 mL.The liquid solvent has a mass of 22.3 g and a density of 0.865 g/mL. Determine the mass of the solid given its density is 2.50 g/mL.

Answer 1

Density is defined as mass per unit volume or mass/volume.

We are given the density as 2.50 g/ml and asked to find the mass. So, we need to know the volume of the solid. We can get that from the data given.

Total volume (liquid + solid) = 86.0 ml

Volume of the liquid alone = 22.3 g x 1 ml/0.865 g = 25.8 ml

Volume of solid = total volume - volume of liquid = 86.0 ml - 25.8 ml = 60.2 ml

So, we now know the density and the volume of the solid, so we can find the mass.

Density = mass/volume

Mass = density x volume = 2.50 g/ml x 60.2 ml = 151 g (to 3 sig. figs.)