CHEMISTRY 101 - PRINCIPLES of CHEMISTRY I Fall 2002

AnnouncementsDiscovery has started! Dont forget to go!The tutorial center is open (MEYR 145).Exam 1 is 2 weeks from Friday.1For most solids, solubility increases as temperature increases.TrueFalse2true22/14/14For which of the following does pressure influence solubility?Solid dissolving in a liquidGas dissolving in a liquidLiquid dissolving in a liquidAll of the above.None of the above.3Gas in liquid32/14/14Which of the following interactions are important in forming a solution?Solute-solventSolvent-solventSolute-soluteAll of the above.None of the above.4all42/14/14What is the most important factor in determining the formation of a solution?Intramolecular forcesIntermolecular forcesWater

5Intermolecular forces52/14/14When/why does a solution form?6Cg = k PgPredict whether C7H16 is more likely to dissolve in carbon tetrachloride or in water.H2OCCl47CCl472/14/14Predict whether Na2SO4 is more likely to dissolve in carbon tetrachloride or in water.H2OCCl48H2O2/14/148Indicate the type of solute-solvent interaction that should be most important in a solution of hexane (C6H14) in benzene (C6H6).LDFH-bondingDipole-dipoleIon-dipole

9LDF92/14/14Indicate the type of solute-solvent interaction that should be most important in a solution of propanol (CH3CH2CH2OH) in water.H-bondingIon-dipoleDipole-dipoleLDF

10H-bond102/14/14Calculate the concentration of CO2 in a soft drink that is bottled with a partial pressure of 4.0 atm over the liquid at 25C. For CO2 in water at this temp., k = 3.1 x 10-2 mol/L-atm.

2.6 M1.7 M0.59 M0.12 M11Cg = k PgC = (3.1 x 10-2 mol/L-atm)(4.0 atm) = 0.12 MC1/P1 = C2/P2(0.12 M/4.0 atm) = (C2/3.0x10^-4 atm)C = 9.3 x 10^-6 M112/14/14The concentration of CO2 in a soft drink under a pressure of 2.3 atm is 0.071 M. Calculate the concentration of CO2 in a soft drink after the bottle is opened and equilibrates at the same temperature under a CO2 partial pressure of 3.0 x 10-4 atm.

6.1 x 10-5 M2.7 x 10-6 M8.4 x 10-5 M9.3 x 10-6 M12Cg = k PgC = (3.1 x 10-2 mol/L-atm)(4.0 atm) = 0.12 MC1/P1 = C2/P2(0.12 M/4.0 atm) = (C2/3.0x10^-4 atm)C = 9.3 x 10^-6 M122/14/14The partial pressure of O2 in air at sea level is 0.21 atm. Use Henrys Law (k = 1.38x10-3 M/atm) to calculate the molar concentration of O2 in the surface water of a mountain lake saturated with air at 20C and atmospheric pressure of 665 torr.

2.5 x 10-4 M1.2 x 10-3 M2.9 x 10-4 M7.3 x 10-3 M13Recall from Ch. 10: Pi =(xi)(PT)The total pressure (atmospheric pressure) at sea level is 1 atm, therefore:Xoxygen = 0.21 atm/1 atm = 0.21Poxygen = (xoxygen)(PT) = (0.21)(665 torr) = 138 torrCg = (1.38x10-3 M/atm)(138 torr)(1 atm/760 torr)Cg = 2.5x10-4 M

132/14/1414AnnouncementsDiscovery has started! Dont forget to go!The tutorial center is open (MEYR 145).Exam 1 is 2 weeks from Friday.15For most solids, solubility decreases as temperature increases.TrueFalse16false162/14/14For which of the following does pressure influence solubility?Solid dissolving in a liquidGas dissolving in a liquidLiquid dissolving in a liquidAll of the above.None of the above.17Gas in liquid172/14/14Which of the following interactions are important in forming a solution?Solute-solventSolvent-solventSolute-soluteAll of the above.None of the above.18all182/14/14What is the most important factor in determining the formation of a solution?Intramolecular forcesIntermolecular forcesWater

19Intermolecular forces192/14/14When/why does a solution form?20Cg = k PgPredict whether methanol (CH3OH) is more likely to dissolve in carbon tetrachloride or in water.H2OCCl421H2O2/14/1421Predict whether I2 is more likely to dissolve in carbon tetrachloride or in water.H2OCCl422CCl42/14/1422Indicate the type of solute-solvent interaction that should be most important in a solution of CaCl2 in water.LDFH-bondingDipole-dipoleIon-dipole

23Ion-dipole232/14/14Calculate the concentration of CO2 in a soft drink that is bottled with a partial pressure of 4.0 atm over the liquid at 25C. For CO2 in water at this temp., k = 3.1 x 10-2 mol/L-atm.

2.6 M1.7 M0.59 M0.12 M24Cg = k PgC = (3.1 x 10-2 mol/L-atm)(4.0 atm) = 0.12 MC1/P1 = C2/P2(0.12 M/4.0 atm) = (C2/3.0x10^-4 atm)C = 9.3 x 10^-6 M242/14/14The concentration of CO2 in a soft drink under a pressure of 2.3 atm is 0.071 M. Calculate the concentration of CO2 in a soft drink after the bottle is opened and equilibrates at the same temperature under a CO2 partial pressure of 3.0 x 10-4 atm.

6.1 x 10-5 M2.7 x 10-6 M8.4 x 10-5 M9.3 x 10-6 M25Cg = k PgC = (3.1 x 10-2 mol/L-atm)(4.0 atm) = 0.12 MC1/P1 = C2/P2(0.12 M/4.0 atm) = (C2/3.0x10^-4 atm)C = 9.3 x 10^-6 M252/14/14The partial pressure of O2 in air at sea level is 0.21 atm. Use Henrys Law (k = 1.38x10-3 M/atm) to calculate the molar concentration of O2 in the surface water of a mountain lake saturated with air at 20C and atmospheric pressure of 665 torr.

2.5 x 10-4 M1.2 x 10-3 M2.9 x 10-4 M7.3 x 10-3 M26Recall from Ch. 10: Pi =(xi)(PT)The total pressure (atmospheric pressure) at sea level is 1 atm, therefore:Xoxygen = 0.21 atm/1 atm = 0.21Poxygen = (xoxygen)(PT) = (0.21)(665 torr) = 138 torrCg = (1.38x10-3 M/atm)(138 torr)(1 atm/760 torr)Cg = 2.5x10-4 M

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