Exam 2 Flashcards
(4 cards)
Why might the assumption of constant temperature along an absorption column be incorrect?
The absorption process is often exothermic releasing heat of absorption, which may or may not be dissipated quickly enough to maintain constant temperature.
What characteristics of a given pair of different molecules determines if they will have similar boiling points and why?
The size of the molecule affects the size of the dispersion force interaction. The functional groups on a molecule affect the type of inter-molecular interaction possible, such as OH and NH2 groups allowing hydrogen bonding which increases the size of interaction.
Why does the form of the Type I/Langmuir isotherm tend to a horizontal plateau at high pressure?
The flat plateau at the top of the isotherm indicates that the adsorbed amount is reaching maximum capacity. For monolayers the surface coverage is reaching 100%, and for microporous solids the pore volume is being filled completely.
What is an ‘entrainer’?
Azeotropic distillation, the extraneous mass-separating agent is relatively volatile and is known as an entrainer.
This entrainer forms either a low-boiling binary azeotrope with one of the keys or a ternary azeotrope with both keys.
