1) What mass of sodium chloride is required to lower the freezing point of 6.50 kg of water to -31.7ºC?
(a) 2.55 kg
(b) 3.24 kg
(c) 5.68 kg
(d) 6.47 kg
(e) 8.52 kg
2) What mass of bromine needs to be added to 950. ml of carbon tetrachloride to make a 0.25 m solution? The density of Br2 is 3.12 g/mL and that of CCl4 is 1.59 g/mL.
(a) 38 g
(b) 60. g
(c) 40. g
(d) 64 g
3) What mass of lithium sulfate is required to lower the freezing point of 7.20 kg of water to -31.7ºC?
(a) 4.50 kg
(b) 5.68 kg
(c) 3.55 kg
(d) 6.75 kg
(e) 13.5 kg
4) What mass of caffeine needs to be added to 450. ml of acetone to make a 0.85 m solution? The density of caffeine is 1.23 g/mL, the molecular mass of caffeine is 194.20 g, the density of acetone is 0.790 g/mL and the molecular mass of acetone is 58.08 g.
(a) 170 g
(b) 74 g
(c) 130 g
(d) 59 g
5) What mass of trimethylene glycol, HOCH2CH2CH2OH, is required to lower the freezing point of 7.50 kg of water to -27.8ºC?
(a) 4.26 kg
(b) 14.9 kg
(c) 2.84 kg
(d) 8.52 kg
(e) 5.52 kg
6) What mass of citric acid needs to be added to 950. ml of acetone to make a 0.30 m solution? The density of citric acid is 1.67 g/mL, the molecular mass of citric acid is 192.10 g, the density of acetone is 0.790 g/mL and the molecular mass of acetone is 58.08 g.
(a) 55 g
(b) 58 g
(c) 46 g
(d) 43 g