the same conditions effuses in 2.42 minutes.Calculate the molecular weight of the unknown gas. time raten MW MW timen MW,气time， time =2.02gmol1 11.1)2 =42.5 g mol- timeu 2.42 B3.Calculate the pressure exerted by 1.00 mol of CH ina 500 mL vessel at 25.0Cusing (a)The ideal gas law nRT 1.00 mol(.082Latm K-'molX25+273)K.9 atm P= 0.500L (b)The van der Waals equation.For CH4)a=2.25 L2atm mol2 and b=0.0428 L mol p=- 1.00 mol(0.082 Latm K-'mol-25+273)KLatm1.00 mol 0.500L-1.00mol(0.0428Lmol) mo20.500L =53.45atm-9.00atm =44.5atm Part C.Answer any five of questions C1-C7(20 marks each).If you answer more than five,the best five will be used to calculate your total mark. C1.Nitrogen dioxide decomposes according to 2 NO2)=2 NO)+Ox()At a certain temperature,Kp is extremely small(4.48x).If0.75 atm of NO is placed in a vessel at this temperature,find the equilibrium partial pressures of all three gases p(NOz).atm p(NO),atm p(O2),atm 3the same conditions effuses in 2.42 minutes. Calculate the molecular weight of the unknown gas. ?? H ?? H ?? H ?? ?? H H ?? ?? H H time rate MW time rate MW MW time MW time time . MW MW . g mol . g mol time . − − = = ⎛ ⎞ = ⎜ ⎟ ⎜ ⎟ ⎝ ⎠ ⎛ ⎞ ⎛ ⎞ == = ⎜ ⎟ ⎜ ⎟ ⎜ ⎟ ⎝ ⎠ ⎝ ⎠ 2 2 2 2 2 2 2 2 2 2 1 1 11 1 2 02 42 5 2 42 B3. Calculate the pressure exerted by 1.00 mol of CH4(g) in a 500 mL vessel at 25.0o C using: (a) The ideal gas law nRT . mol( . L atm K mol )( )K p . V . L − − + = = = 1 1 1 00 0 082 25 273 48 9 0 500 atm (b) The van der Waals equation. For CH4(g), a = 2.25 L2 atm mol-2 and b = 0.0428 L mol-1 nRT n p a V nb V . mol( . L atm K mol )( )K L atm . mol . . L . mol( . L mol ) mol . L . atm . atm . atm − − − ⎛ ⎞ = − ⎜ ⎟ − ⎝ ⎠ + ⎛ ⎞ = − ⎜ ⎟ − ⎝ ⎠ = − = 2 2 1 1 2 1 2 1 00 0 082 25 273 1 00 2 25 0 500 1 00 0 0428 0 500 53 45 9 00 44 5 Part C. Answer any five of questions C1 – C7 (20 marks each). If you answer more than five, the best five will be used to calculate your total mark. C1. Nitrogen dioxide decomposes according to 2 NO2(g) = 2 NO(g) + O2(g). At a certain temperature, Kp is extremely small (4.48×10-13). If 0.75 atm of NO2(g) is placed in a vessel at this temperature, find the equilibrium partial pressures of all three gases. p(NO2), atm p(NO), atm p(O2), atm 3