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signature:282version numberShayak Sen(ss67795)EXAM 1Biberdorf Class (50203)Water DataKf= 1.86◦C/mKb= 0.512◦C/mCice= 2.09 J/g◦CCwater= 4.184 J/g◦CCsteam= 2.09 J/g◦CΔHfusion= 334 J/gΔHvapor= 2260 J/gPlease refer to the back of the bubble sheet for more info.NOTE:Please keep your Exam copy intact (all pages still stapled). You must turn in yourexam copy, plus your bubble sheet, scratch paper, and your free response section.
Version 282 – Exam 1 – biberdorf – (50203)2Thisprint-outshouldhave20questions.Multiple-choice questions may continue onthe next column or page – find all choicesbefore answering.0014.0pointsIn which of the following will a given sam-ple of PbBr2(Ksp= 4.6×10−6)be the leastsoluble?1.100 mL of 0.01 M KOH2.100 mL of pure water3.100 mL of 0.002 M NaBr4.100 mL of 0.05 M HBrcorrect5.100 mL of 0.07 M HClExplanation:PbBr2will have a common ion effect withany solution with Pb2+or Br−in them. Twoof the solutions have Br−and those will causePbBr2to be less soluble.The 0.05 M HBrsolution has a higher concentration of Br−than the NaBr solution, which means it willhave the bigger effect on solubility, meaningLESS PbBr2will dissolve in that solution.0024.0pointsWhen 1.28 g of polypeptide are placed in14.0 L of water at room temperature, the so-lution exerts an osmotic pressure of 4.23 torr.What is the molar mass of the polypeptide?1.more than 550. g/mol2.38.8 g/mol3.158. g/mol4.402. g/molcorrect5.388. g/mol6.40.1 g/mol7.less than 25.0 g/molExplanation:Π =iMRTpolypeptide is non electrolyteandi= 14.23/760 = (1)M(0.08206)(298.15)M= 0.0002275 mol/Lx 14L = 0.003185 mol1.28g/0.003186 mol = 402. g/mol0034.0pointsA 9.386 M aqueous solution of sulfuric acidhas a density of 1.5091 g/mL. Calculate themolality of sulfuric acid in this solution.1.6.81m2.15.95mcorrect3.12.84m4.19.62mExplanation:none0044.0pointsA 250 gram sample of liquid water is heatedfrom 50◦C to vapor at 110◦C. What arethe signs for the change in enthalpy and thechange in entropy for this process?1.ΔH >0,ΔS <02.ΔH <0,ΔS <03.ΔH= 0,ΔS >04.ΔH >0,ΔS >0correct5.ΔH <0,ΔS >0Explanation:None0054.0pointsWhich of the following shows the right equa-tion for the ion product of iron(III) sulfate?