DAT Bio chapter 6 Flashcards
ranking of intermolecular forces
ion dipole
hydrogen bonding
dipole dipole
dispersion forces (everything has this)
how to find lowest melting point of similar molecular weight?
Like boiling point it increases with intermolecular forces
so find the weakest intermolecular forces
branching rule for melting point
more branching equals higher melting point
branching rule for boiling point
more branching lowers boiling point
Intramolecular forces
metallic
ionic
network
the stronger a molecules intermolecular forces
high boiling point
high melting point
lower its vapor pressure
why is linear molecules have a higher dispersion force than some branched molecules
because linear can stack on top of each other making a tighter bond
Extraction techniques relies on what
using polar and non polar solvents
acid base extractions:::::
For carboxylic acids use
phenols use
amines use
naoh and nahco3
naoh
HCL
what is distillation
separates mixtures of two or more volatile liquids
Volatile : boilable: anyting that turns into gas without much difficulty
what is fractional distillation
when two volatile liquids have boiling points that are close to each together
what is recrystallization
dissolves an impure compound in hot solvent and gradually precipitate the pure compound as the solution cools down.
( not good for separating volatile substance)
if no crystals form during cooling, scratch the sides
THINk of hot chocolate
________ intermolecular force= ____ boiling point =____ vapor pressure
weak ( less stuck together)
lowers ( so does not need a high boiling point
increases (wants to vaporize)
Branching rule for melting point
increase branching = increase melting point
organic is always the top layer T/F
false. depends on density. some things such as dicholomethane or chloroform is heavier so itll be bottom layer
