Organic Chem Lab (I) Final

Question 1

what is the protective equipment for ochem lab?

Answer 1

GOGGLES*
lab coat (recommended)
gloves (recommended)

Question 2

what do you do if there’s a small fire?

Answer 2

fire blanket

fire extinguisher

Question 3

what do you do if there’s a large fire?

Answer 3

EVACUATE

TA calls fire dept

Question 4

what do you do if there’s a minor injury?

Answer 4

wash it with soap and water

Question 5

what do you do if a chemical gets in your eye?

Answer 5

emergency eye wash station

Question 6

what do you do if there’s a major injury?

Answer 6

inform TA
fill out incident report
use emergency shower if needed
see a doc

Question 7

what do you do if there’s an acid spill?

Answer 7

neutralize w/ bicarb

clean like normal

Question 8

what do you do if there’s an organic spill?

Answer 8

wipe up
treat with acetone
wipe up again (with gloves on!)

Question 9

how are molecules held together?

Answer 9

various intermolecular forces

Question 10

how are solid molecules held together?

Answer 10

neatly, lattice, little wiggle room

Question 11

how are liquid molecules held together?

Answer 11

randomly, no particular order

Question 12

melting

Answer 12

increased energy of a substance

going from a solid to a liquid

Question 13

melting point

Answer 13

point at which a solid is completely melted

usually a range from when it starts until it’s complete

Question 14

what do impurities in a substance to do the melting point?

Answer 14

they decrease the MP

lattice packing

Question 15

eutectic point

Answer 15

a “dip” in the melting point diagram of the MP of TWO compounds

Question 16

how does the melting point of TWO substances compare to that one just ONE

Answer 16

it tends to be lower

have a wider range

Question 17

how can the identity and purity of a compound be checked

Answer 17

measuring MP and mixed MP

Question 18

crystallization

Answer 18

the process of forming crystals

Question 19

is it possible to crystallize only one compound from a mixture?

Answer 19

yes, it is a purification technique

Question 20

what percent is considered a “pure” compound?

Answer 20

greater than 70%

Question 21

what is an ideal agent for crystallization?

Answer 21

available
cheap
volatile
dissolves compound poorly at low temps
dissolves compound well at high temps
does not dissolve impurities OR dissolves them very well- so they don't crystallize with the compound

Question 22

7 steps of crystallization

Answer 22

1- choosing solvent
2- dissolving the solvent
3- decolorizing the solvent
4- filtering the suspended solids
5- crystallizing the solute
6- collecting and washing the crystals
7- drying the product

Question 23

compounds involved in the synthesis of dibenzylacetone

Answer 23

benzylaldehyde and acetone
ethanol = solvent
NaOH = catalyst
dibenzylacetone = end product w/ enantiomers
benzylacetone = possible impurity

Question 24

what is the ratio of acetone and benzaldehyde?

Answer 24

1:2

Question 25

how can traces of NaOH be eliminated?

Answer 25

water wash

Question 26

how long does the synthesis of dibenzylacetone take

Answer 26

30 minutes

Question 27

how does chromatography work?

Answer 27

it relies on the difference of affinity of compounds | as the solvent moves, it carries the compound with it

Question 28

what is the driving reason that chromatography works?

Answer 28

polarity of molecules

Question 29

what is the Rf?

Answer 29

retention factor; used to determine a compound's mobility | ratio of the distance that its traveled

Question 30

irregularities of thin layer chromatography

Answer 30

``` spots are too faint spots are large and overlapping all spots are at the top all spots are near the bottom spots are large and diffuse spots are smudged levels of spots are uneven or curved ```

Question 31

what does liquid liquid extraction rely on for acid base extraction

Answer 31

difference in affinity of the compounds

Question 32

what is a good solvent for extraction?

Answer 32

cheap volatile dissolves the other substance well does not mix with the other solvent used

Question 33

evaporation

Answer 33

the phase change between a liquid and a gas

Question 34

higher the pressure...

Answer 34

...the higher the boiling point

Question 35

where is the boiling point of a mixture?

Answer 35

in between the boiling points of the compounds

Question 36

how should compounds be heated in the lab?

Answer 36

thoroughly and evenly, and NOT TOO FAST otherwise the equilibrium can be disturbed

Question 37

what is the purpose of boiling chips?

Answer 37

provide bubbling constant centers; allow for it to boil evenly

Question 38

what compounds are involved in hypochlorite oxidation?

Answer 38

``` cyclohexanol (starting material) sodium hypochlorite - reagent acetic acid - catalyst cyclohexanone - product sodium sulfite - used to neutralize the acidic product NaOH - neutralization cacl2 - removes excess water ```