Jika pada kasus terdapat suatu kondisi dimana molekul N2 pada tekanan 7,514 x 10-9 Pa dan temperatur 1000 K dan jumlah molekul per m2 adalah 5,44 x 1011 dan pada ketinggian 106 m dengan diameter tumbukan molekul N2 adalah 5 x 10-10 m maka N2 akan memiliki kecepatan rata-rata sebesar: = = 0,869 x 103 m.s-1Sehingga N2 mempunyai frekuensi tumbukan sebesar = = 5,25x 106 s-1Jadi N2 akan mempunyai jarak bebas rata-rata sebesar= = 0,165 x 10-3 m

30% N250% CO15% H25% O2

STP: 1 Atm, 0C

Fraksi mol=fraksi gasAsumsi 100L

Fraksi Berat: fraksi mol x Mr

Mr rata2: fraksi mol dikali Mr

Tekanan parsialFraksi mol x tekanan totalDensitasMr/22,4

V80859095100v80859095100

N40625122n385950102

320052704501140200304050154500950200

Ave84,7933985,49418

ave86,19497

Sum280

3) pada tekanan 1 atm, tentukan mr dari vapormass of vessel filled with dry air at 25C = 97.432 gmass of vessel filled with vapor at 175C = 99.420 gmass filled water at 23C = 550 g1. Hitung volume tabung (m/rho)2. Hitung berat tabung (berat tabung isi udara-berat udara) berat udara=volume x rho udara (1.2gr/cm3)3. Hitung berat vapor (berat penuh-berat tabung). PVMr=mRT->Mr=mRT/PV

A mixture ofO2and nitrous oxide,N2O, is sometimes used as a mild anesthetic in dental surgery. A certain mixture of these gases has a density of 1.482 g L1at 25 and 0.980atm. What was the mole-percent ofN2Oin this mixture?SOLUTIONFirst, find the density the gas would have at STP:

The molar mass of the mixture is (1.65 g L1)(22.4 L mol1) = 37.0 g mol1. The molecular weights ofO2andN2are 32 and 44, respectively. 37.0 is 5/12 of the difference between the molar masses of the two pure gases. Since the density of a gas mixture is directly proportional to its average molar mass, the mole fraction of the heavier gas in the mixture is also 5/12:37324432=512=0.42

Find the composition of a mixture of CO2(44 g/mol) and methane CH4(16 g/mol) that has a STP density of 1.214g/L.SOLUTIONThe density of a mixture of these two gases will be directly proportional to its composition, varying between that of pure methane and pure CO2. We begin by finding these two densities:For CO2:(44 g/mol) (22.4 L/mol) = 1.964 g/LFor CH4:(16 g/mol) (22.4 L/mol) = 0.714 g/LIfxis the mole fraction of CO2and (1x) is the mole fraction of CH4, we can write1.964 x + 0.714 (1x) = 1.214(Does this make sense? Notice that if x = 0, the density would be that of pure CH4, while if it were 1, it would be that of pure CO2.)Expanding the above equation and solving for x yields the mole fractions of 0.40 for CO2and 0.60 for CH4.