Test 2

Question 1

What is an atom?

Answer 1

the smallest particle of an element.

Question 2

How are the atomic numbers structured?

Answer 2

Question 3

How to calculate with atomic amu? example 6 protons and 6 neutrons.

Answer 3

Question 4

The principal quantum number (n)

Answer 4

Question 5

Azimuthal quantum number (l)

Answer 5

value of l: 0 1 2 3 4 …..
letter designation: s p d f g …..

n=1 → 1s
n=2 → 2s 2p
n=3 → 3s 3p 3d
n=4 → 4s 4p 4d 4f

Question 6

Magnetic quantum number (m)

Answer 6

Values from 1- to +1

S orbital m = 0 => 1 orientation

P orbital m = -1, 0, +1 => 3 orientations

D orbital m = -2, -1, 0, +1, +2 => 5 orientations

Question 7

Noble gases

Answer 7

None of them react, noble gas is stable
All have filled valence energy (8 valence electrons) except He that has only 2

Question 8

Chemical bonds

Answer 8

Atoms ionize and transfer electrons (ionic bonds) or share electrons (covalent bonds) in order to reach Noble Gas electron configuration. (octet rule)

Question 9

When do covalent bonds form?

Answer 9

when two atoms share valence electrons.

Question 10

When do polar covalent bonds form?

Answer 10

when two atoms share valence electrons
unequally.

One end of the bond has a fractional negative charge and the other a positive charge

Question 11

When do ionic bonds form?

Answer 11

when one atom donates or transfers valence electrons to
another atom.

Question 12

What is electronegativity?

Answer 12

the tendency of an atom to attract electrons towards itself.

Question 13

Molecular orbitals(MO)

Answer 13

mathematical function describing the wave-like behavior of an electron in a molecule.

Question 14

σ MO and σ* MO

Answer 14

Sigma bond, strongest type of covalent bond

electrons spend most of
their time in the region directly between the two nuclei.

and

electrons spend
most of their time away from the region between the two
nuclei.

Question 15

π MO

Answer 15

Pi bonds

are formed by side-ways (lateral) overlapping
between p atomic orbitals

Question 16

Structure of methane

Answer 16

CH4, sp3, σ bonds

Question 17

Structure of ethane

Answer 17

C2H6, two overlapping sp3, σ bonds

Question 18

Structure of ethene

Answer 18

C2H4, three sp2, σ bonds

Question 19

Structure of ethyne

Answer 19

C2H2, two sp, σ bonds

Question 20

Cis and trans isomers

Answer 20

Question 21

Hydrocarbon classifications

Answer 21

Alkanes -> single bond -> -ane

Alkenes -> double bond -> -ene

Alkynes -> triple bond -> -yne

Aromatics -> rings

Question 22

Classification of carbon atoms in alkanes

Answer 22

Primary carbon - one carbon neighbor

Secondary carbon - two carbon neighbors

tertiary carbon - three carbon neighbors

quaternary carbon - four carbon neighbors

Question 23

What are Van der Waals forces?

Answer 23

intermolecular forces, such as the covalent bonds that hold atoms
together in molecules

hold molecules together in a liquid or solid

weaker than covalent bonds

Question 24

(Van der Waals) Dipole - dipole interaction

Answer 24

Molecules arrange themselves with positive and negative ends towards each other. (attraction) because they move freely in a liquid they experience both attraction and repulsion interactions simultaneously.

Question 25

(Van der Waals) London dispersion forces

Answer 25

Temporary fluctuations in the
electron distributions within
atoms and nonpolar molecules
could result in the formation of
short-lived instantaneous dipole
moments, which produce
attractive forces between otherwise nonpolar substances.

Question 26

(Van der Waals) Hydrogen bond

Answer 26

A hydrogen bond is an attraction between two atoms that already participate in other chemical bonds. One of the atoms is hydrogen, while the other may be any electronegative atom, such as oxygen, chlorine, or fluorine.

Question 27

Halogenation of alkanes

Answer 27

Ex.
CH3CH2Cl - chloroethane (ethyl chloride)

Question 28

Stability of the free radicals (alkanes) and same case for carbocations (just add positive charge to carbon)

Answer 28

3* > 2* > 1* > methyl

Question 29

alkane halogenation - radical chain reaction

Answer 29

Question 30

Cycloalkanes general formula

Answer 30

Get the prefix cyclo- before the names
CnH2(n+1-g)

n = number of C atoms
g = number of rings in the molecule

Question 31

Cyclohexane non-planar conformations

Answer 31

chair (most stable)
boat
twist boat
half chair

Question 32

What is benzene?

Answer 32

Benzene is an organic chemical compound with the molecular
formula C6H6 (think of satan)

Flat ring of sp2

It has six π electrons

Question 33

Benzene - electrophilic aromatic substitution

Answer 33

Question 34

Benzene derivatives

Answer 34

1,2-dichlorobenzene

1,3-dichlorobenzene

1,4-dichlorobenzene

Question 35

what are Stereoisomers?

Answer 35

have their atoms connected in the same sequence, but they differ in the arrangement of their atoms in
the space.

Question 36

When is an object chiral?

Answer 36

an object is chiral when its mirror image is different from the original
object. (left and right hand)

Question 37

What are enantiomers?

Answer 37

Molecules with the same mirror image

Question 38

What are diastereomers?

Answer 38

Molecules that are not mirror images of each other. (cis-trans, conformers)

Question 39

chirality center

Answer 39

Guarantees the molecule is chiral
- has four different groups attached

Question 40

R or S enantiomer?

Answer 40

Question 41

Lewis acid

Answer 41

accepts an electron pair (an electrophile)
and has vacant orbitals.

Question 42

Lewis base

Answer 42

donates an electron pair (a nucleophile)
and has lone-pair electrons.

Question 43

nucleophile

Answer 43

a species with an unshared electron pair, reacts with an alkyl halide by replacing the halogen substituent.

Question 44

Answer 44

Nucleophilic substitution reaction

Question 45

Answer 45

SN2 reaction

Question 46

Answer 46

SN1 reaction