Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CHEM 110 > Block 1 - Foundations > Flashcards

Block 1 - Foundations Flashcards

1
Q

Heteroatoms

A

Any atom not C or H

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

Second and third bond strength relative to first bond

A

Second bond (and third) must be weaker than the first

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

Covalent bonds form when…

A

… atomic orbitals overlap to form molecular orbits

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

Atomic orbital overlaps can be…

A
  1. Good (end-on), i.e. sigma bonds (σ-bonds)
  2. Weak (side-on), i.e. pi bonds (π-bonds aka DBEs)

Pi bonds weaker than sigma bonds

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

Single, double, triple bonds (σ or π)

A

Single: 1 sigma bond –> inert
Double: 1 sigma bond, 1 pi bond –> reactive
Triple: 1 sigma bond, 2 pi bonds

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

Hybridisation

A

The mixing of atomic orbitals belonging to the same atom, but having slightly different energies so a redistribution of energy takes place between them –> results in the formation of new orbitals of equal energies and identical shape

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

Rotation around double and triple bonds - π bonds

A

Rotation about double and triple bonds would require breaking a π-bond –> incurs significant energy penalty

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

C bonded to 4 atoms (single bonds)

A

Geometry: Tetrahedral (109.5°)
Hybridisation: sp3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

C bonded to 3 atoms (two single bonds, one double bond)

A

Geometry: Trigonal planar (120°)
Hybridisation: sp2

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

C bonded to 2 atoms (one single bond, one triple bond OR two double bonds)

A

Geometry: Linear (180°)
Hybridisation: sp

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

Periodic table: First 20 elements

A

H, He, Li, Be, B, C, N, O, F, Ne, Na, Mg, Al, Si, P, S, Cl, Ar, K, Ca

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

Periodic trends: Electronegativity, ionisation energy, atomic radius

A

Electronegativity: Increases up and right
Ionisation energy: Increases up and right
Atomic radius: Decreases up and right

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

Isomers

A

Compounds with same molecular formula, but different arrangement in space

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

Constitutional isomers

A

Different sequence of bonds

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

Double bond equivalents (DBEs) = ½ (2n4 + n3 - n1 + 2)

where…

A

DBE = ½ (2n4 + n3 - n1 + 2)
where n4 = C, n3 = N, n1 = H or halogens
O doesn’t appear in DBE formula

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

Stereoisomers

A

Different arrangement of groups in space

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

Conformational isomers

A

Differ by rotation about a single bond

No bond breaking required

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

Configurational isomers

A

Interconversion requires breaking bonds

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

Enantiomers

A

Non-superimposable mirror images
Stereogenic centre (C)
Chiral

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

Diastereomers

A

Not mirror images

Non-superimposable

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

Types of isomers

A

Isomers –> Constitutional and Stereoisomers
Stereoisomers –> Conformational and Configurational
Configurational –> Enantiomers and Diastereomers

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

Define conformer

A

The conformation of a molecule; a particular shape it adopts as a result of rotation about bonds

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

Conformational isomers - types of projection

A 
Sawhorse projection (views molecules from an oblique angle)
Newman projection (views molecules end-on)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Interconversion of conformers

A

Staggered —rotate 60°—> Eclipsed

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

Staggered conformers vs Eclipsed conformers

A

Staggered: atoms fit ‘between’ other atoms, most stable
Eclipsed: atoms fit directly ‘behind’ other atoms, least stable

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

Types of staggered and eclipse conformers

A

Staggered; anti-conformer: most stable
Eclipsed
Staggered; gauche-conformer
Eclipsed; syn-conformer: least stable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Cyclohexane conformers

A

Bond 109° preferred –> not flat/planar
Boat
Chair

28
Q

Chair conformers: types of H atoms

A

Axial: pointing vertically up or down
Equitorial: point in other directions

29
Q

Lowest energy conformation

A

Chair conformer

30
Q

Ring flip

A

Converting from ‘Chair A’ to ‘Chair B’

Where all axial groups become equatorial groups and vice versa

31
Q

Generally, the favoured conformer for substituted cyclohexanes have the largest atom(s)/group(s) in the ______

A

Equatorial

32
Q

CIP rules

A

Determines whether E or Z configuration

Higher atomic number = higher priority = ranks higher

33
Q

E vs Z configuration

A 
Divide horizontally (i.e. like --------)
E-configuration: two higher priority groups are on opposite sides of double bond
Z-configuration: two higher priority groups are on same side of double bond
34
Q

Stereogenic centre

A

Asymmetric carbon

35
Q

Achiral

A

Where sp3 C has two identical atoms/groups attached so molecule is superimposable

36
Q

Chiral

A

Where sp3 C has different atoms/groups attached so molecule is non-superimposable on its mirror image

37
Q

Racemic mixture

A

1:1 ratio (equal amounts) of enantiomers

Rotates light equally in both directions –> overall rotation is zero

38
Q

R vs S configuration

A

R: priority of highest substituents decreases in a clockwise direction
S: priority of highest substituents decreases in an anti-clockwise direction

39
Q

Enantiomers, identical/meso and diastereomers

A

Enantiomers: mirror images, non-superimposable
Identical/meso: mirror images, superimposable
Diastereomers: not mirror images, non-superimposable

40
Q

If octane is attached to something, it’s called ____

A

Stemane

41
Q

CH3O name

A

Methoxy

42
Q

Naming cycloalkanes

A

Add ‘cyclo’ to front of name, e.g. cyclopentane

43
Q

Double bonds are more readily polarised due to…

A

The relative mobility of pi electrons, i.e. C=O is more polar than C-O bond

44
Q

Branching and bpt

A

IF strongest when molecules are in close proximity, so decreased branching = increased bpt as molecules can stack closer together

45
Q

Similar vs different molecular weights - bpt

A

Similar M: more polar functional groups = higher bpt

Different M: difference in temporary dipole-dipole interactions that has greatest effect on bpt

46
Q

Polarity and water solubility

A

More polar = more water soluble (hydrophilic)

Less polar = more lipid soluble (lipophilic)

47
Q

Polar stationary phase: Polar vs non-polar solutes

A

Polar solutes are more attracted to the polar stationary phase and move slowly
Non-polar solutes are less attracted to the polar surface of stationary phase and so move more rapidly

48
Q

Which molecule has higher bpt question - key points

A
  1. If similar size = similar dispersion forces
  2. Most polar bonds
  3. Strongest IM interactions (what is it)
    Therefore, highest bpt
49
Q

Which molecule moves fastest on chromatography column - key points

A
  1. Least polar molecule
  2. No polar bonds
  3. Interacts least with polar stationary phase
    Therefore moves fastest on chromatography column
50
Q

Types of curly arrows

A

Half arrow = 1 electron moving

Full arrow = 2 electrons moving

51
Q

Homolytic bond cleavage

A

One electron from the bond ends up on each of the atoms which were formally bonded (i.e. covalent bond cleaves symmetrically)

52
Q

Heterolytic bond cleavage

A

Both electrons from the bond end up on one of the atoms which were formally bonded (i.e. covalent bond cleaves asymmetrically)

53
Q

If ‘A’ is more electronegative than C, what happens?

CH3C-A

A

Bonds will break:
CH3C+ + A- (carbocation + anion)
e.g. A = Cl, O, Br

54
Q

If ‘A’ is less electronegative than C, what happens?

CH3C-A

A

Bonds will break:
CH3C- + A+ (carbanion + cation)
e.g. A = metal

55
Q

Geometry of carbocations

A

Planar (sp2 hybridised)

56
Q

Relative stability of carbocations

A

Tertiary > Secondary > Primary > Methyl

57
Q

Classes of reaction + sub-classifications

A

Substitution
Addition
Elimination

Polar/non-polar (radical)
Involving a nucleophilic/electrophilic reagent
Nature of substrate (alkyl, acyl, aryl)

58
Q

Substitution reactions

A

Where one atom/group is replaced by another through breaking and formation of sigma bonds

59
Q

Addition reactions

A

A pi-bond breaks, and is replaced by 2 sigma bonds

60
Q

Elimination reactions

A

Two sigma-bonds break, and one pi-bond forms

61
Q

Reaction mechanism

A

The detailed pathway by which reactants are converted to products
Often requires multiple steps (elementary reaction) that occur sequentially

62
Q

Reactive intermediates

A

Species involved in a reaction mechanism that may be unstable or short-lived

63
Q

Nucleophilic substitution

A

Reagent is a nucleophile
SN1 occurs step-wise (bond-breaking then bond-forming)
SN2 occurs in a single step (bond-breaking/forming simultaneous)

64
Q

Nucleophile

A

Electron rich –> electron donor
Can be neutral or negatively charged
Have either lone pairs of e- or e- in pi-bonds

65
Q

Electrophile

A

Electron deficient –> electron acceptor

Can be neutral or positively charged

66
Q

Polar reaction occurs when…

A

A nucleophile reacts with an electrophile to form a new covalent bond

67
Q

The terms cis and trans are used to describe…

A

The relative position of substituents on a ring

CHEM 110 (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions