Chemistry, 06.11.2019 21:31 katherineweightman

If a 100 kg mol mixture of n-hexane and n-octane containing 50 mole% n-hexane is to be separated by flash distillation @ 1 atm to obtain 40 kg mol in distillated (ie. v=40 kg mol) a) whatare the compositions of the liquid and vapor phases when v = 40 kg mol? b) what is the flash drum temperature?

Answers: 3

Show answers

Answers

Answer from: amandasantiago2001

(a) $x_1=0.34\\x_2=0.66\\y_1=0.74\\y_2=0.24$

(b) 95.24^0C

Explanation:

Hello,

The Rachford-Rice equation should be used in this case:

$\frac{z_1(K_1-1)}{1+V/F(K_1-1)} +\frac{z_2(K_2-1)}{1+V/F(K_2-1)} =0\\\frac{0.5(\frac{P_{1,sat}}{P}-1)}{1+V/F(\frac{P_{1,sat}}{P}-1)} +\frac{z_2(\frac{P_{2,sat}}{P}-1)}{1+V/F(\frac{P_{2,sat}}{P}-1)} =0$

The distribution coefficients could be approximated via Raoult's law and the Antoine equation for the vapor pressure:

$K_i=\frac{P_{i,sat}}{P}=\frac{10^{A-\frac{B}{C+T} }}{P}$

For n-hexane: A=6,9895, B=1216,92 and C=227,451

For n-octane: A=7,14462, B=1498,96 and C=225,874

*Those values and the Antoine law are used in °C and mmHg.

Replacing each value in the Rachford-Rice equation and solving for T, one gets the flash drum temperature as 95.24°C (attached picture), thus, the compositions in both the liquid and the vapor phases are:

$x_1=\frac{z_1}{1+V/F(K_1-1)}=\frac{0.5}{1+0.4*(2.175-1)} =0.34\\x_2=1-x_1=0.66\\y1=K_1*x_1=2.175*0.34=0.74\\y_2=1-y_1=0.24$

Best regards.

If a 100 kg mol mixture of n-hexane and n-octane containing 50 mole% n-hexane is to be separated by

Answer from: Quest

vanderwaal's forces of attraction are the electrostatic intermolecular forces that exist in a molecule due to the temporary or permanent dipoles that are developed in a molecule. in $h_{2}s$ , the major intermolecular forces are dipole-dipole interactions as the molecule is polar (bent structure). so the vanderwaal's forces of interaction in between $h_{2}s$ molecules are the permanent dipole-dipole interactions that develop due to the dipole that exists in between the polar h - s bond. the positively charged hydrogen atom is attracted towards the negative end of the dipole that is sulfur of the adjacent $h_{2}s$ molecule. therefore, these forces of attraction are relatively stronger than that of london dispersion forces that exist in non polar molecules.

Answer from: Quest

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.

chemical decomposition is opposite of chemical synthesis.

Other questions on the subject: Chemistry

Chemistry, 22.06.2019 09:30, janetexcoelho

What does the mass of 0.7891 mol of ferric oxide (fe2o3)

Answers: 1

continue

Chemistry, 22.06.2019 15:00, alanmarcus22

What does the symbol (–hfus) indicate in a phase change?

Answers: 1

continue

Chemistry, 22.06.2019 18:30, tanviknawale

Which sample at stp has the same number of atoms as 18 liters of ne at stp

Answers: 1

continue

Chemistry, 22.06.2019 23:00, liv467

Which of your 24 wells had indications that a chemical reaction occurred? how were you able to tell that a chemical reaction occurred? which of your 24 wells had indications that a physical reaction occurred? how were you able to tell that a physical reaction occurred? report on both mixing and evaporation. make a general statement about whether your hypotheses were validated or rejected. must your hypotheses be correct for this to be a successful laboratory?

Answers: 3

continue

You know the right answer?

If a 100 kg mol mixture of n-hexane and n-octane containing 50 mole% n-hexane is to be separated by...