lab final

Question 1

during recrystallization process, vacuum filtration removes what

Answer 1

filtrate

Question 2

how can you confirm compound purity using melting points?

Answer 2

mix compound with pure form and test the melting point

Question 3

how do you know a compound is pure or impure?

Answer 3

pure = precise melting point, impure = broad melting point

Question 4

simple vs fractional distillation

Answer 4

simple is single vaporization-condesation cycle while fractional is multiple cycles

Question 5

under what circumstances would you preform fractional distillation

Answer 5

if the boiling points of both compounds were close together

Question 6

formula for % recovery

Answer 6

(mass recovered material (purified compound)/mass of starting mixture) x 100

Question 7

what is distillation

Answer 7

technique to purify liquids by vaporization and condensation

Question 8

how long is a c-c single bond?

Answer 8

1.54 angstroms

Question 9

how long is a c=c double bond

Answer 9

1.34 angstroms

Question 10

hat is the ideal angle around an sp3 c

Answer 10

109.5 degress

Question 11

what is the ideal angle around an sp2 c

Answer 11

120 degrees

Question 12

trans or cis more stable, why?

Answer 12

trans is more stable because there is not as much repulsion and strain

Question 13

equatorial or axial have lower energy?

Answer 13

equatorial

Question 14

Rf equation

Answer 14

distance traveled by compound/distance traveled by solvent

Question 15

is hexane polar or non polar

Answer 15

non polar

Question 16

is acetone polar or nonpolar

Answer 16

polar

Question 17

which compounds will go further on the TLC plat?

Answer 17

depends on the mixture of the solvent. if solvent is more polar, polar molecules will go further, but is the solvent is non polar than non polar molecules will go further.

Question 18

e-factor formula

Answer 18

mass waste/mass product

Question 19

are polar solvents more likely to go through SN1 or SN2 reactions?

Answer 19

SN1

Question 20

saturated is what at room temperature

Answer 20

solid, butter

Question 21

unsaturated is what at room temp

Answer 21

liquid, oil

Question 22

more c-c double bonds =

Answer 22

lower melting point

Question 23

cis or trans on fatty acid chains had lower melting point

Answer 23

cis

Question 24

% yield formula

Answer 24

actual yield/theoretical yield

Question 25

theoretical yield

Answer 25

change moles to grams, then % yield

Question 26

in a funnel what compound will be on the bottom?

Answer 26

the compound with the higher density