Concentrations of Solutions Molarity and Molality

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Part A
A solution contains 0.173g of glycerol, C3H8O3, and 20.0 g of water.
The density of water is 1.00g/mL
What are the Molarity, Molality and % m / m concentrations of the solution?

Molarity = M = mole solute /liter solution

Mole glycerol = 0.173 g C3H8O3 (1 mol C3H8O3 / 92 g)
Mole glycerol = 1.88 x 10-3 mol C3H8O3

Volume of water = 20 g H2O (1 mL / 1 g) = 20 mL = 0.02 L

(Note: Since the amount of solute (glycerol) is very small, it can be assumed ...