Separation

Question 1

Importance of Separation Process

Answer 1

➀ Raw mat do not contain pure chemicals = isolation of valuable substance
➁ Rxn do not reach full convertion = removal of reactants to be recycled
➂ Reactions yield by-products = need to purify
➃ Rxns done in solvent = recovery of solvent

Question 2

Two major distinction of separation process

Answer 2

➀ Mechanical Separation - mechanics

➁ Thermal Separation - thermodynamics

Question 3

Give some types of separation process (phase transformation and driving force)

Answer 3

➀ Distillation L → V, Heat
➁ Absorption G → L, Heat
➂ Extraction L → L, regeneration 
➃ Drying L → V, Heat
➄ Crystallization L → S, Cooling

Question 4

Give and describe (flow chart) the three general flow schemes

Answer 4

➀ Cross Current
➁ Co Current
➂ Counter Current

Question 5

What is Raoult’s Law?

Answer 5

● vapor pressure of a solvent above a solution is equal to the vapor pressure of the pure solvent at the same temperature scaled by the mole fraction of the solvent present
● only applicable to IDEAL solution

Question 6

Explain and draw Gibbs’ Phase Rule

Answer 6

Draw

Question 7

Give characteristic of a good solvent

Answer 7

● High selectivity
● Low solubility
● Non-reacting with other substance - Inert
● Regenerable
● Low Toxicity, Cost-effective

Question 8

Draw a basic Extraction Design

Answer 8

Draw

Question 9

Draw a typical Distillation Design

Answer 9

Draw

Question 10

Differentiate Distillation versus Extraction

Answer 10

● Distillation - method mpurifying a liquid by a process of heating and cooling

● Extraction - method of purifying a mixture based on solubility (selectivity)