17.54 Torr and the solubility of MgF2at 20◦Cis 8 mg per 100 g of water.1.24.81 Torr2.15.02 Torr3.17.54 Torrcorrect4.None of these5.21.06 Torr6.19.84 Torr
Yoon, Seong Meen – Exam 1 – Due: Sep 18 2007, 3:00 pm – Inst: James Holcombe7018(part 1 of 1) 10 pointsCalculate the number of moles of oxygen thatwill dissolve in 45 L of water at 20◦C if the par-tial pressure of oxygen is 0.21 atm.Henry’sconstant for oxygen is 0.0013molL·atm.In a closed vessel containing water the pres-sure is 18 torr. If we add more water to thevessel, the pressureWhich of the following is true if the distil-late is collected from a distillation apparatuswhile the solution boils?1.713 torr2.504 torrcorrect3.112 torr4.256 torr5.52 torrExplanation:021(part 1 of 1) 10 pointsConsider the temperature composition dia-gram of a binary mixture of A and B whichforms a minimum boiling azeotrope: InitiallyXA= 0.6.00.20.40.60.81.0020406080100120140XAboiling temperature (◦C)1.XAin the beakerwill remain the same.2.XAin the beakerwill approach 0.3.XAin the beakerwill approach 1.4.XAin the beakerwill approach 0.3.cor-rectExplanation:022(part 1 of 1) 10 pointsMixing 17.6 kg of ethylene glycol (commercialantifreeze, C2H6O2) with 6.00 gal of waterlowers the freezing point to-10.0◦F. Supposeyou wanted to accomplish the same thing withsugar (sucrose, C12H22O11) instead of ethy-lene glycol.How many kilograms of sucrosewould you use? 1 gallon = 3.785 liters.Kfforwater = 1.86◦C/m.1.3.09 kg2.97.1 kgcorrect
Yoon, Seong Meen – Exam 1 – Due: Sep 18 2007, 3:00 pm – Inst: James Holcombe83.4.68×10-3kg4.17.6 kg5.6019 kgExplanation:023(part 1 of 1) 10 pointsSeveralinterestingobservationsfromtheworld around you are listed below.Whichof these is NOT explained by a colligativeproperty?