Chemistry Calculations

Question

3. The blood serum acetone level for a person is determined to be 1.8 mg of acetone per 100 mL of

serum. Express this concentration as % (v/v) is liquid acetone has a density of 0.79 g/mL.

4. Calculate the following:

a. The number of grams of NaOH in 20.0 mL of a 1.20% (w/v) NaOH solution.

b. The number of milliliters of alcohol in 500 mL of a 20.0% (v/v) solution.

Answer 1

3) % volume = volume acetone / total volume (x100%) or mls/100 mls

volume of acetone = 1.8 mg x 1 g / 1000 mg x 1 ml / 0.79 g = 0.02278 mls

% (v/v) = 0.02278 mls / 100 mls (x100%) = 0.023% (v/v)

4a) 1.20% (w/v) NaOH = 1.20 g NaOH / 100. mls solution

20 ml x 1.20 g / 100 mls = 0.240 g NaOH

b) 20.0% (v/v) = 20 mls alcohol / 100 mls solution

20 mls/100 mls x 500 mls = 100 mls alcohol