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1.)A gas mixture contains 74% nitrogen and 26% oxygen.If the total pressure is 1

ID: 1007876 • Letter: 1

Question

1.)A gas mixture contains 74% nitrogen and 26% oxygen.If the total pressure is 1.02 atm what are the partial pressures of each component? Express your answers using two significant figures. Enter your answers numerically separated by a comma.

2.) The mass of an evacuated 265 mL flask is 143.147 g . The mass of the flask filled with 267 torr of an unknown gas at 35 C is 144.197 g . Calculate the molar mass of the unknown gas.

3..)Consider the following reaction: 2SO2(g)+O2(g)2SO3(g)

a. What is the theoretical yield of SO3?

b.If 131.8 mL of SO3 is collected (measured at STP), what is the percent yield for the reaction?

Explanation / Answer

PT   = PN2 +PO2

1.02 = PN2 +PO2

PN2    = 0.74*1.02   = 0.75atm

PO2 = 0.26*1.02     = 0.2652atm

2. PV = nRT

    n = W/M

P     = 267torr = 267/760 = 0.35atm

V    = 265ml   = 0.265L

W    = 144.197g

T =35C0 = 35+273 =308K

R = 0.0821L-atm/mole-K

PV = WRT/M

M    = WRT/PV

      = 144.197*0.0821*308/0.35*0.265 = 39312g/mole

3. 2SO2(g)+O2(g)2SO3(g) but missing the data

   volume of SO3 is at STP = 2*22400ml = 44800ml

percentage yield = Actual yield*100/Theoretical yield

                             = 131.8*100/44800 = 0.29%