Ochem Flashcards

What are the types of intramolecular forces (in order of strength)?

Ionic interactions, hydrogen bonding, induced dipole induced dipole and dipole-dipole

What is the only bending vibration on the IR?

N-H

What is a polymorph?

It is the same molecules however with different packing, properties and intramolecular interactions

How many Cs are water soluble per polar group?

4-5

What is mixed melting point used for?

an ID method

not purity

What strong peak is usually present around 3000 cm?

C-H

What is a broad stretch usually around 3000 cm?

O-H

What is one fang around 3200?

nh

What has the double peaks around 3200?

Nh2

What is he hair beard around 3k on ir?

COO

What should be checked in region 3 of the IR?

carbonyl

What is a polymorph?

same molecules different packing, different properties and different intramolecular interactions

What is the ideal solvent for recrystalization?

soluble hot, insoluble cold, volatile and non reactive

What are some problems with recrystalization?

if there is similar solubility it cannot be done

What should happen if the solute does not dissolve when doing an recrystallization?

heat and wait

What should you do if your solute does not crystalize?

cool and wait or scratch sides

What happens when the recovery of the recrystallization is low?

too dilute and tare flasks

What does it mean with the crystals bring an high recovery?

not dry, tare issues,

what is enthalpy?

bonds broken - bonds made

What should Kd be for good seperation?

3/2

What is the equation for KD?

[org]/[aq]

What does nrining a solution do?

pulls water out of the solution by making the solution more polar

What is benzoic acids kd in ethyl acetate?

2

What causes the emulsions in our tea solution?

saponins

How are tannins removed?

they perform basic hydrolysis when in the ch2cl2 or na2co3

What does the melting range of a compound tell us about a compound?

a physical property that identifies a compound and is an indication of purity

What are mixed melting points used for?

to identify compounds by mixing them together

does not indicate purity of any compound

How does IR spectroscopy work?

organic molecules absorb infrared light when the energy corresponds to specific molecular vibrations and rotation, the IR spectrum shows the inverted peals at the frequencies where they are absorbed

Do organic or inorganic molecules have higher melting points?

inorganic molecules

What molecules have greater vapor pressur?

smaller molecules, symetric molecules and molecules with smaller dipole moments

9-fluorenone

How much hot solvent should be added for recrystallization?

the minimum amount of solvent because the concentration of the compound should be high and supersaturated

How can colored soluble impurities be removed?

by adding activated carbon

What can be done if crystals do not form?

adding seed crystal, scratching side of glass, and reheating solution to remove excess solvent

What is liquid-liquid extraction?

separation method based on differential solubility of components in a mixture between two immiscible solvents

What is the insoluble compound present in the teas solution?

cellulose

What are the water soluble compound present in the teas solution?

saponins, tannins and teas protein and pigments

MTBE

ethyl acetate

caffeine

benzoic acid

How are acidic organic compounds seperated?

can be turned to water soluble anions using inorganic bases

How are basic organic compounds separated?

can be turned to water soluble cations by treatment with inorganic acids