Atoms & Molecules

Question 1

Explanation for the incomplete separation of labetalol enantiomers

Answer 1

The chiral stationary phase has high specificity for the orientation of chiral hydroxyl groups, but not for chiral alkyl groups

Question 2

Two chiral centers =

Answer 2

Four stereoisomers

Question 3

Two chiral centers =

Answer 3

Four stereoisomers

Question 4

Decreasing acidity?

Answer 4

Molecules in middle (highest), then molecule towards an end, then no branched molecules

Question 5

Diastereomers

Answer 5

Have different chemical and physical

Question 6

Structural isomers

Answer 6

Refers to molecules with the same molecular formula but a different order of bonding

Question 7

Enantiomers

Answer 7

Mirror images of one another - differ in small, but not density, B.P., or IR spectra

Question 8

Sp2 hybridized carbons

Answer 8

Bonded 3 times

Question 9

In order to interact with a magnetic field,

Answer 9

A nuclei must have a magnetic moment; that is, they must have an odd number of neutrons plus protons

Question 10

Oxygen atom is:

Answer 10

Paramagnetic, because it has two unpaired electrons

Question 11

Diamagnetic

Answer 11

Has an even number of electrons

Question 12

True of acetone

Answer 12

It exists as a pair of tautomers, of which the keto form predominates; occurs because the carbon-oxygen double bond (carbonyl) is much stronger than the carbon-carbon double bond
Acetone has a low B.P., and is polar, but aprotic

Question 13

Sulfur is very unstable in its diatomic state, S2. This molecule differs from O2 because:

Answer 13

The double bond in S2 is longer

Question 14

Primary amino group

Answer 14

A group in which nitrogen is attached to one carbon

Question 15

NAD

Answer 15

Composed of two nucleotides joined by their phosphate groups

Question 16

Fission rxns can be initiated by bombarding nuclei with neurons, would protons work instead?

Answer 16

No, because neutrons, unlike protons, do not experience repulsion from the nucleus

Question 17

S designation

Answer 17

Atoms are arranged in a counterclockwise direction from highest priority to lowest priority

Question 18

R designation

Answer 18

Atoms are arranged in clockwise direction from highest to lowest priority

Question 19

Priority from highest to lowest

Answer 19

1. Carboxy (carboxylic acid or -oic acid)
2. Sulfo (sulfonic acid)
3. Ester (-oate)
4. Acid halide (-oyl halide)
5. Amide (carbamoyl- or amide)
6. Nitro (nitrile or cyano-)
7. Aldehyde (formyl- or -al / -carbaldehyde)
8. Ketone (oxo or -one)
9. Alcohol (hydroxy- or -ol)
10. Thiol (mercapto or -thiol)

Question 20

Sulfonate

Answer 20

Stabilizes, making carboxy hydrogens highly acidic

Question 21

Nitrates

Answer 21

All of them are soluble, nothing added that will produce a percipitate

Question 22

Amine

Answer 22

(n-H or NH2)

Question 23

Amide

Answer 23

(HN-C=O)

Question 24

Carboxylic acid

Answer 24

COOH

Question 25

Imine

Answer 25

C=N

Question 26

Size of radii

Answer 26

K > K+ > Na+

Question 27

Number of neutrons in nucleus?

Answer 27

86Kr - 36 (# on periodic table) = 50

Question 28

Number of neutrons in nucleus?

Answer 28

86Kr - 36 (# on periodic table) = 50

Question 29

Molecular formula of a heterocyclic aromatic compound, pyrrole?

Answer 29

C4H5N