last minute

Question 1

pH of solution is LESS than pKa of the compound:

Answer 1

compound will be in its acidic form
*some molecules in basic form will become protonated

Question 2

pH of solution is GREATER than pKa of the compound:

Answer 2

compound will be in basic form
*some molecules in acidic form will be deprotonated

Question 3

what affects BP?

Answer 3

attractive forces (vanderwaals < dipole < H bonds)

surface area

branching

Question 4

what affects MP?

Answer 4

packing

odd number of carbons pass LESS tightly = lower MP

Question 5

most stable conformer of cyclohexane?

Answer 5

the chair conformer:

has NO eclipsing interactions
bond angles are 109.5

Question 6

a substituent is more stable in __ position because…

Answer 6

equatorial; no 1,3-diaxial interactions

Question 7

most stable newman projection

Answer 7

antiparallel conformation

Question 8

compounds with different ___ CANNOT be separated

Answer 8

conformations

Question 9

compounds with different ___ CAN be separated

Answer 9

configurations

Question 10

in fisher projections, rotations of __ are allowed, but rotations of ___ are not allowed

Answer 10

180 is allowed
90 is not allowed

Question 11

vinyllic carbon

Answer 11

the sp2 carbon of an alkene

Question 12

allylic carbon

Answer 12

the carbon adjacent to the vinyllic carbon

Question 13

_______ : all molecules are in the same plane

Answer 13

trigonal planar

Question 14

no asymmetric to 1 asymmetric center:

Answer 14

racemic mixture

Question 15

1 asymmetric center to 2 asymmetric centers:

Answer 15

diastereomers

Question 16

m/Z = 43 could be

Answer 16

+CH2-CH2-CH3

Question 17

m/z = 29 could be

Answer 17

+CH2 - CH3

Question 18

m/z = 57 could be

Answer 18

+CH2 - CH2 - CH2 - CH3

Question 19

Br is 50.5% 79Br and 49.5% 81Br, so…

Answer 19

the Molecular ion peak (M+) has 79 Br and has an equally tall M+2 peak that has 81 Br

Question 20

Cl is 75.5% 35Cl and 24.5% 37Cl, so….

Answer 20

the molecular ion peak M+ is 3x higher than the M+2 peak

Question 21

more conjugated double bonds =

Answer 21

longer wavelength

Question 22

IR: more polar bond =

Answer 22

more intense absorption

Question 23

IR: lighter atoms sow absorption bands…

Answer 23

at larger wavenumber

Question 24

IR: stronger bonds (bigger bond order) =

Answer 24

show absorption bands at larger wavenumber

Question 25

deshielded protons sense a ___ effective magnetic field

Answer 25

larger

Question 26

the chemical shift of protons attached to sp2 carbons…

Answer 26

appear at higher frequencies than predicted

Question 27

splitting is observed IF:

Answer 27

the nonequivalent protons are separated by no more than 3 bonds

Question 28

what to look for in mass spec when dealing with1 Nitrogen:

Answer 28

-odd molecular ion mass
-even fragment mass