Ethylene oxide is produced by the catalytic oxidation of ethylene: 2C2H4 + O2 > 2C2H4O

An undesired competing reaction is the combustion of the ethylene: C2H4+ 3O2 > 2CO2 + 2H2O
Thed feed to the reactor (not the fresh feed to the process) contains 3 moles of ethylene per mole of oxygen. The single pass conversion of ethylene is 20% and for every 100 moles of ethylene consumed in the reactor, 90 moles of ethylene oxide emerges in the reactor products. A multiple unit process is used to seperate the products: ethylene and oxygen are recylced to the reactor, ethylene oxide is sold as a product, and carbon dioxide and water are discarded.
a) Assume a quantity of the reactor feed stream as the basis of the calculation, perform a degree of freedom analysis, and write the equations you would use to calculate i) the molar flow rates of etyhlene and oxygen in the fresh feed, ii) the production rate of ethylene oxide, and iii) the overall conversion of ethylene. dont do any calculations.
b) Calculate these quanitities
c) Calculate the molar flow rates of ethylene and oxygen in the fresh feed needed to produce 1 ton per hour of ethylene oxide.

the missing options are :

(1) lower boiling point and a lower freezing point(2) lower boiling point and a higher freezing point(3) higher boiling point and a lower freezing point(4) higher boiling point and a higher freezing point

answer : the correct answer is option (3) higher boiling point and a lower freezing point

explanation :

when a non volatile solute is added to a solvent like water, it results in elevation of boiling point.

let us find the increase in boiling point of water when cacl₂ is added to water to make a solution of 1 m

step 1 : find molality of the solution

let us assume we have 1 l of solution.

let us convert this to grams of cacl₂.

molar mass of cacl2 is 111 g/mol

grams of cacl₂ =

mass of solute = 111 g

assuming density of solution same as water which is 1g/ml we have ,

mass of solution = density * volume

mass of solution =

mass of solution = mass of solvent + mass of solute

mass of solute = 1000g - 111g

mass of solute 889 g = 0.889 kg

the molality of the solution can be calculated as

molality = 1.12 m

step 2 : find boiling point elevation.

the elevation in boiling point is calculated as

here δtb = boiling point elevation

i = vant hoff factor which is the number of ions formed by the solute .

cacl₂ dissociates as

it forms 3 ions . therefore,

i = 3

m = molality which is 1.12 m

kb is constant for a given solvent. for water it is 0.512

the boiling point of water increases by 1.7 °c

step 3: find freezing point depression.

when a non volatile solute is added to water, it results in decrease in freezing point.

the formula to find freezing point depression is

kf is constant for water and its value is 1.86

the freezing point of water decreases by 6.2 °c

therefore we can say that, the solution will have a higher boiling point and a lower freezing point