If 30.0 g of ethanol is required in the preparation of a medication, what volume of ethanol would be necessary (densityethanol= 0.791 g/ml)?

37.9 mL

Density is the ratio between the mass and volume of a substance, or between the mass of a substance and the mass of an equal volume of another substance taken as a standard. If we want to know what is the volume that represents a certain mass of a liquid we can use density as a conversion factor.

To know the volume (V) of ethanol required for the preparation of the drug we must divide the mass (m) of ethanol between the density of this liquid:

d = → V =

→ V =

→ V = 37.9 mL

The volume of ethanol required to prepared the medication 37.9 mL