Exam 1 Flashcards

1
Q

How do you calculate formal charge?

A

FC = VE-NBE-B

Formal Charge = # valence electrons - nonbonding electrons - bonding electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which compounds usually have nonbonding electrons in their stable compounds?

A

Oxygen, nitrogen, and the halogens (F,Cl,Br,I)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Name the halogens.

A

F, Cl, Br, I

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Common Bonding Patterns (Uncharged) for C, N, O, H and halogens

A

Helpful to remember these when drawing Lewis structures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Common Bonding Patterns in Organic Compounds and Ions

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What allows for a hydrocarbon to be a stable compound?

A

1) An octet on all atoms
2) Even number of hydrogens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

General rule for the number of hydrogen atoms in stable hydrocarbons?

A

Even number of hydrogen atoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Pauling Electronegativities

A
  • know the trend and values!
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Define stereoisomer

A

-isomers that differ only in how their atoms are oriented in space
-Atoms are bonded in the same order**
-different compounds
Type of stereoisomer-> geometric isomers (cis-trans)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Type of Stereoisomer?

A

Geometric isomer:
-differ in the geometry of the groups on a double bond:
Two types of geometric isomers:
a) cis-isomers: same side
b) trans-isomers: opposite sides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What must be true for a cis-trans isomerism to exist?

A

there must be two DIFFERENT groups on each end of the double bond; if two of the groups are identical, this is not a cis-trans isomer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Sp3 hybridized state

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Sp2 hybridized state

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Sp hybridized state

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

6 Different types of geometry we need to know

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Formal Charge: Negative Charge

A

1 more electron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Formal Charge: Positive Charge

A

1 less electron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Formal Charge: Carbon atom with three bonds

A

one lone pair and negative formal charge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Oxygen - Formal Charge

A

No FC = 2 bonds, 2 lone pairs
- FC = 1 bond, 3 lone pairs
+ FC = 3 bonds, 1 lone pair

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Nitrogen - Formal Charge

A

No FC = 3 bonds, 1 lone pair
- FC = 2 bonds, 2 lone pairs
+ FC = 4 bonds, no lone pairs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Carbon - Formal Charge

A

No formal Charge = 4 bonds
- FC = 3 bonds, 1 lone pair
+ FC = 3 bonds, no lone pair

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Remember:
C-H bond usually considered nonpolar

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Don’t Forget:
Include the dipole moment for lone pairs! Always directed toward the lone pairs because they are the most electronegative

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Is trigonal planar symmetrical?

A

yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

The attractive forces that cause molecules to associate into solids and liquids?

A
  1. London dispersion forces- present in all molecules
  2. Dipole-Dipole forces of POLAR molecules
  3. “Hydrogen bonds” that link molecules having -OH or -NH groups
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

To predict boiling points, look for differences in:

A
  1. hydrogen bonding
  2. molecular weight and SA
  3. dipole moments
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

When determining water solubility between two molecules that both carry -OH bonds. What could be the determining factor?

A

The number of carbons in the carbon chain; the fewer the number of carbons, the smaller the molecule, the more soluble the molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Acid base reactions favor ________

A

the weaker acid and the weaker base.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

A strong acid has ______.

A

a weaker conj. base

33
Q

A weaker acid has _______.

A

a stronger conj. base

34
Q

The stronger the acid, the more it dissociates, giving a ______ Ka value.

A

larger

35
Q

pkA values ______ as the Ka value ________.

A

increase; decreases

36
Q

Weak acid has a small or large kA value?

A

small; because it has less dissociation

37
Q

strong acid has a small or large kA value?

A

large; because it dissociates more

38
Q

Problem Solving Steps: Predicting Acid-Base Equilibrium Positions

A
39
Q

Acidity and Basicity Limitations in common solvents.
Name the Solvent, Structure, pKA limit and limiting structure, pKb limit and limiting structure.

A
40
Q

Water and Alcohols (R-O-H) can react as ______ and ______, and they limit the strength of ________ and _______ dissolved in them.

A

weak acids; weak bases
strong acids; strong bases

41
Q

Ethers (R-O-R) can react as _______, and they limit the strength of ______ , but not ______ dissolved in them.

A

weak bases
strong acids
bases

42
Q

Alkanes do not react as either ______ or _____, and they do not limit the strength of ____ or _____ dissolved in them.

A

acids; bases
acids; bases

43
Q
A
44
Q

Acidity increases as you go down the periodic table, as the size of the element increases.

A
45
Q
A
46
Q

Acidity depends on _____

A

the stability of the conj. base.

47
Q
A
48
Q

Acidity is increased by:

A
  1. stronger electron withdrawing substituents
  2. additional electron withdrawing substituents
  3. closer proximity of the electron withdrawing substituent to the acidic group
49
Q

FActo

A
50
Q

Factors that affect the stability of conjugate bases:

A
  1. electronegativity
  2. size
  3. resonance
51
Q

Acidity_____ as you go __ and __ the periodic table.

A

increases
left to right
down

52
Q

Define isomers.

A

Different chemical compounds with the same chemical formula

53
Q

Define constitutional isomers.

A

Differ in the order in which the atoms are connected.

54
Q

Define stereoisomers.

A

Isomers that differ only in the orientation of atoms in space.

55
Q

Define enantiomers.

A

Mirror-image stereoisomers

56
Q

Define diastereomers.

A

non-mirror image stereoisomers

57
Q

Two commandments of drawing resonance structures?

A
  1. tho shall not break a single bond.
  2. thou shall not exceed an octet for second-row elements (C,N,O,F)
58
Q

Can second-row elements (C,N,O,F) have more than 4 bonds?

A

NO! NEVER!
The sum of (bonds) + (lone pairs) for a second-row element can never exceed the number four

59
Q

Carbon with a negative charge has ____ pair(s) and ____ bond(s).

A

1 lone pair
3 bonds

60
Q

Why do we need resonance structures?

A

They tell us areas of high and low electron density.

61
Q

Conservation of Charge

A

-you cannot change the total charge when drawing resonance structures
-if the first structure has a negative charge, then the resonance structure you draw should also have a negative charge

62
Q

3 Questions to ask when drawing resonance structures?

A
  1. Can you convert any lone pairs into pi bonds?
    2.Can you convert any pi bonds into lone pairs?
  2. C
    an you convert any pi bonds into pi bonds?
63
Q

Name the 5 patterns to recognize when drawing resonance structures:

A
  1. a lone pair next to a pi bond-meaning the lone pair is separated from the double bond by exactly one single bond- no more and no less
  2. a lone pair next to a C+
  3. a pi bond next to C+
  4. a pi bond between two atoms, where one of those atoms is electronegative
  5. pi bonds going all the way around a ring
64
Q

Rules for ranking resonance forms?

A
  1. As many octets as possible
  2. As many bonds as possible
  3. Negative charge on most electronegative element
  4. Least charge separation
65
Q

If HA is willing to give up the proton, then HA is a ______.

A

strong acid

66
Q

If HA is not willing to give up its proton, then it’s a ______.

A

weak acid

67
Q

How can we tell whether or not HA is willing to give up its proton?

A

We can figure it out by looking at the conjugate base.

68
Q

Notice in this reaction, that the conjugate base has a negative charge. The real question is: how stable is that negative charge?

H-A —> A-

If that charge is stable, then HA will or will not give up the proton, and therefore HA will be a strong or weak acid .
If that charge is not stable, then HA will or will not give up the proton, therefore HA will be a strong or weak acid.

A

will; strong acid
will not; weak acid

69
Q

When determining charge stability, what factor do we consider for elements on the same row?

A

Electronegativity

70
Q

When determining charge stability, what factor do we consider for elements in the same column?

A

size

71
Q

Four important factors for determining charge stability:

A
  1. Determining what atom the charge is on (involves looking at electronegativity for elements in the same row; and looking at size for elements in the same column)
  2. Resonance
    -allows for the charge to be “delocalized” or spread over more than one atom
    *Two rules: A) the more delocalized the better. A charge spread over four atoms is more stable than a charge spread over two atoms
    B) ONE oxygen is better than many carbon atoms!!!
  3. Induction- “pulling” of electron density
  4. Hybridized orbitals (sp > sp2 >sp3)

*Remember the acronym ARIO to help remember these factors!

72
Q

.How does the induction effect work to stabilize charges?

A

the induction effect of electronegative atoms stabilize the negative charge by withdrawing some of the electron density away from the negative charge

73
Q

Stabilizing inductive effects are stronger when they are closer or further away from the negative chage?

A

The closer the inductive effect to the negative charge; the more stabilizing!

74
Q

Define electrophile.

A

Electron “loving”; an acid

75
Q

Define nucleophile.

A

Nucleus loving, wants to give away electrons; bases

76
Q

Low BDE =

A

stable free radical

77
Q

BDE ____ as from ___ to _____ across the periodic table

A

decreases; left to right

Low BDE = more stable

78
Q

Rank the order of increasing stability of free radicals

A
79
Q

Bromination =
Chlorination =
Fluorination =

A

highly selective
moderately selective
nonselective