A solution of ethanol in water is prepared by dissolving 61.0 mL of ethanol (density = 0.79g/mL) in enough water to make 280.0 mL of solution. What is the molarity of the ethanol in this solution?
definition of molarity = #mols/L.
mass ethanol = m = volume x density = 61.0 mL x 0.79 g/mL =?? grams.
mols ethanol = ??g/molar mass ethanol.
Liters = 0.280.
61.0 mL x 0.79 g/mL = 48.19 g
48.19 g / 46.0 molar mass = 1.05 mol
1.05 mol / .280 L = 3.74 M