userdata-paziras-Chem101-Chap_12A

07gethyleneglyco l 1mo lwater mo leswater2000gx

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Unformatted text preview: f HC2H3O2 in vinegar. g HC2H3O2 0.8527 mo les HC2H3O2 60.06 g HC2H3O2 1 L vinegar 1 mL vinegar ? ¾¾¾¾ x 100 = ¾¾¾¾¾¾¾¾¾ x ¾¾¾¾¾¾¾ x ¾¾¾¾¾ x ¾¾¾¾¾¾ = 5.975% g vinegar 1 L vinegar 1 mo le HC2H3O2 1000 mL vinegar 1.0052g vinegar % by mass ® Molarity A sugar syrup so lut ion contains 15.0 % sugar, C12H22O11 , by mass and has a densit y of 1.06 g/mL. What is the mo larit y of this so lution? mo les C12H22O11 15.0 g C12H22O11 1 mo le C12H22O11 1.06 g syrup 1000 mL syrup ? ¾¾¾¾¾¾¾ = ¾¾¾¾¾¾¾ x ¾¾¾¾¾¾¾ x ¾¾¾¾¾¾ x ¾¾¾¾¾ = 0.465 M L syrup 100. g syrup 342.3 g C12H22O11 1 mL syrup 1 L syrup 11 Chemistry 101 Chapter 12 MOLALITY & MOLE FRACTION Molality What is the mo lalit y o f a solut ion containing 5.67 g of glucose (C6H12O6) disso lved in 25.2 g of water? mo les so lute mo les C6H12O6 Recall: Molalit y = ¾¾¾¾¾¾ = ¾¾¾¾¾¾ kg solvent kg water 1 mo le C6H12O6 ? mo les C6H12O6 = 5.67 g C6H12O6 x ¾¾¾¾¾¾¾ = 0.0315 mol C6H12O6 180.2 g C6H12O6 1 kg ? kg water = 25.2 g x ¾¾¾ = 0.0252 kg water 1000 g 0.0315 mo l C6H12O6 Molalit y = ¾¾¾¾¾¾¾¾¾ = 1.25 mo lal = 1.25 m 0.0252 kg water Mole Fraction An automobile ant ifreeze so lut ion contains 2.25 kg of ethylene glyco l (C2H6O2) and 2.00 kg of water. A) Find the mo le fract ion of ethylene glyco l in this so lut ion. 1 mo le ethylene glyco l ? mo les ethylene glyco l = 2250 g x ¾¾¾¾¾¾¾¾¾ = 36.25 moles 62.07 g ethylene glyco l 1 mo l water ? mo les water = 2,000 g x ¾¾¾¾¾ = 110.98 mo les 18.02 g Total no. of mo les in so lut ion = 36.25 moles + 110.98 mo les = 147.2 mo les so lut ion 36.25 mo les ethylene glyco l Mole Fract ion of ethylene glyco l = ¾¾¾¾¾¾¾¾¾¾¾ = 0.246 147.2 mo les so lut ion B) Find the Mole Fraction o f water in this so lut ion. 12 Chemistry 101 Chapter 12 VAPOR PRESSURE OF A SOLUTION · Vapor Pressure is the pressure of the vapor over a liquid, measured at equilibrium, at a given temperature. · Vapor Pressure depends on: Ø temperature (increases with temperature) Ø nature of the liquid · Volat ile Liquids have relatively high vapor pressure. · Non volatile Liquids have relat ively low vapor pressure Ex: Water is much more volat ile than Ethylene Glyco l (CH2OH CH2OH) (higher Pv) (lower Pv) It fo llows: Ethyle...
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This document was uploaded on 03/18/2014 for the course CHEM 101 at Los Angeles Mission College.

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