Question

1) A mixture of methyl iodide and water boils at 64 degree centigrade and 1 atm. What weight of methyl iodide would be carried over by 18g of steam during steam distillation?

Answer 1

for methyl iodide, Antoine Equation is log (P, bar)= 4.1554- 1177.88/(T-32.058)

T in K, at t= 64 deg.c= 64+273= 337K, log P(bar)= 4.1554- 1177.88/(337-32.058), Pbar= 1.96 bar=1.96*0.9869atm

=1.93 atm

for water, log Psat (mmHg) = 8.07131-1730.63/(t+233.426)

t in deg.c at 64 deg.c , Psat = 178.90 mm Hg= 178.90/760 atm =0.24 atm=

the mixture boils at 64 deg.c and 1 atm where , 1= x1*0.24 +(1-x1)*1.93 atm, x1= mole fraction of water

1=0.24x1+1.93- 1.93x1

x1*(1,93-0.24)= 0.93

x1= 0.93/(1.93-0.24)= 0.55

mole fraction of water= 0.55 and mole fraction of methyl iodide= 0.45

mole fraction of water= moles of water/total moles=0.55

mole fraction of methyl iodide= moles of methyl iodide/total moles=0.45

moles of water/mole of methyl iodide= 0.55/0.45= 1.22

mole of methyl iodide= moles of water/1.22, moles of water= mass/molar mass = 18/18=1

moles of methyl iodide= 1/1.22= 0.82 moles

molar mass of methyl iodide = 142,mass of methyl iodide= 0.82*142= 116.44 gm