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Classify the type of electrolyte: CH3OH(l) CH3OH(aq) A. strong B. weak C. non Th

ID: 1021313 • Letter: C

Question

Classify the type of electrolyte: CH3OH(l) CH3OH(aq) A. strong B. weak C. non The initial volume of a gas cylinder is 750.0 mL. If the pressure of a gas inside the cylinder changes from to , what is the final volume the gas occupies? A. 630.0 mL B. 321.4 mL C. 3.151 L D. 1.750 L E. none of the above What is the molar mass of a gas that has a density of 0.179 g/L at STP? A. 4 B. 22 C. 8 550 ml of O2 is collected over water at 1.20 atm and 50oC. Calculate the volume of O2(dry) at STP. A. 550 mL B. 501 mL C. 542 mL How many grams of aluminum will 10 fardays plate out? A. 270 B. 90 C. 1.11 15.0g of a substance at -60.0oC is heated to 0oC. Calculate the heat, in calories, gained by the substance. (boiling point -50.0oC, freezing point -84oC, heat of fusion 7.7cal/g, heat of vaoprization 30.0 cal/g , specific heat(solid) 0.50cal/goC , specific heat (liquid) 0.70cal/goC, specific heat (gas) 0.80cal/goC, you may not need to use all this information) A. 1155 B. 2356 C. 6300 Please show work if possible. Thank you

Explanation / Answer

   Classify the type of electrolyte: CH3OH(l) CH3OH(aq)

CH3OH is weak electrolyte.

B. weak

Initial                                                               Final

V1 = 750ml                                                     V2 =

P1   = 840mmHg                                              P2 = 360mmHg

    P1V1     =   P2V2

     V2      = P1V1/P2

                = 840*750/360 = 1760ml >>>> answer

density = 0.179g/L

22.4 L -----------------> 1 mole

1L --------------------> = 1/22.4   = 0.0446 moles

molar mass   = mass/no of moles

                     = 0.179/0.0446 = 4g/mole

A. 4

intial                                                    STP

P1 = 1.2-0.12 = 1.08atm                 P2 = 1

V1 = 550ml                                   V2 =

T1 = 50+273 = 323K                     T2 = 273K

    P1V1/T1    =   P2V2/T2

           V2    = P1V1T2/T1P2

                   = 1.08*550*273/323*1   = 502.05ml >>> answer

B. 501 mL

How many grams of aluminum will 10 fardays plate out

1farady ------------------------> 9 g of Al

10F   ----------------------------> 9*10 = 90g of Al

B. 90