questions
preiou5
c14.docx1. Vapor pressure: arrange the following aqueous solutions in order of increasing vapor pressure at 25oC: 0.35 m C2H4(OH)2 (ethylene glycol, nonvolatile solute); 0.50 m sugar; 0.20 m KBr; and 0.20 m Na2SO4.
(a) C2H4 (OH)2 sugar KBr Na2SO4
(b) Na2SO4 sugarKBr C2H4 (OH)2
(c) sugar C2H4 (OH)2 KBr Na2SO4
(d) KBr sugar Na2SO4 C2H4 (OH)2
2. One gram (1.00 g) of each of the listed substances is dissolved in 50 g of benzene. Which of the solutions has the lowest freezing point?
(b) acetaminophen, C8 H9 NO2
(c) trinitrotoluene, C2H5(NO2)3
(d) naphthalene, C10H8
3. Samples of each of the substances listed below are dissolved in 125g of water. Which of the solutions has the highest boiling point?
(a) 3.0 g sucrose, C12H22O11
(b) 1.0 g glycerol, C3H5(OH)3
(c) 1.0 g propylene glycol, C3H6(OH)2
(d) 2.0 g glucose, C6H12O6
4. Molar mass: Erthritol is a compound that occurs naturally in algae and fungi. It is about twice as sweet as sucrose. A solution of 2.50 g of erythritol in 50.0 g of water freezes at -0.762oC. What is the molar mass of the compound?
(a) 26.9 g/mol
(b) 35.5 g/mol
(c) 122 g/mol
(d) 224 g/mol
