Question

Chemists often use molarity MM, in moles/litermoles/liter, to measure the concentration of solutions. Molarity is a common unit of concentration because the volume of a liquid is very easy to measure. However, the drawback of using molarity is that volume is a temperature-dependent quantity. As temperature changes, density changes, which affects volume. Volume markings for most laboratory glassware are calibrated for room temperature, about 20∘C∘C. Fortunately, there are several other ways of expressing concentration that do not involve volume and are therefore temperature independent.

A 2.400×10−2 MM solution of glycerol (C3H8O3C3H8O3) in water is at 20.0∘C∘C. The sample was created by dissolving a sample of C3H8O3C3H8O3 in water and then bringing the volume up to 1.000 LL. It was determined that the volume of water needed to do this was 999.0 mLmL . The density of water at 20.0∘C∘C is 0.9982 g/mLg/mL. Part A Calculate the molality of the glycerol solution. Part B Calculate the mole fraction of glycerol in this solution. Part C Calculate the concentration of the glycerol solution in percent by mass. Part D Calculate the concentration of the glycerol solution in parts per million.

Answer 1