Terms 2

Question 1

heterolytic bond breaking

Answer 1

associate with acids/bases-unequal bond breaking where all electrons go towards one atom

Question 2

the equilibrium in an acid-base reaction moves from:

Answer 2

stronger acid/base to weaker acid/base

Question 3

when assessing how strong an acid is:

Answer 3

assess the stability of its conjugate base (anion formed), if more stable, products more favoured and so acid is stronger

Question 4

acid

Answer 4

electron pair acceptor (must be able to accept 2 e-)

Question 5

base

Answer 5

electron pair donor (must have at least one lone pair)

Question 6

how to determine relative stability of conjugate base (and thus assess strength of acid)

Answer 6

ARIO

Question 7

1. how to use ATOM to determine stability of conjugate base

Answer 7

consider atom that charge is on
will be more stable if atom is larger (charge is spread out) or more electronegative (better able to bear a negative charge)

Question 8

2. how to use RESONANCE to determine stability of conjugate base

Answer 8

conjugate base will be more stable if it has resonance so that charge is spread over more atoms (lower localized charge density)

Question 9

3. how to use INDUCTIVE EFFECTS to determine stability of conjugate base

Answer 9

conjugate base will be more stable if there is some electronegative atom to PULL EXCESS ELECTRONS AWAY FROM ATOM BEARING NEGATIVE CHARGE

Question 10

4. how to use ORBITAL HYBRIDIZATION to determine stability of conjugate base

Answer 10

conjugate base will be more stable is the atom bearing the negative charge has a higher s-character in its hybridized orbital (electrons are held closer to nucleus)

Question 11

what is an exception where orbital beats atom in determining acidity?

Answer 11

sodium acetylide (NaNH2)

Question 12

when assessing how strong a base is:

Answer 12

look at the stability of the conjugate acid, the more stable the conjugate the stronger the base (opposite in ARIO rules to acid)

Question 13

1. how to use ATOM to determine stability of conjugate acid

Answer 13

consider the atom bearing the positive charge, if it is more electronegative, it is harder to bear positive charge so less stable, if the atom is larger, electron density is lower and also less stable

Question 14

2. how to use RESONANCE to determine stability of conjugate acid

Answer 14

if resonance structures available, the whole structure is less stable

Question 15

3. how to use INDUCTIVE EFFECTS to determine stability of conjugate acid

Answer 15

if an electronegative atom is present to pull more electrons away from ALREADY ELECTRON-DEFICIENT ATOM, then less stable

Question 16

4. how to use ORBITAL SIZE to determine stability of conjugate acid

Answer 16

the more s character in orbital, the less stable.

Question 17

a reaction that results in the oxidation of carbon corresponds to:

Answer 17

an increase in the number of bonds between carbon and oxygen and/or a decrease in the number of C-H bonds: increase in oxidation state (number)

Question 18

a reduction would involve a:

Answer 18

decrease in oxidation state

Question 19

a general rule is that oxidation of carbon occurs when:

Answer 19

a bond between carbon and an atom which is less electronegative than carbon is replaced by a bond to an atom that is more electronegative than carbon (reduction is the reverse)

Question 20

addition reaction

Answer 20

atoms are being added to the reactant

Question 21

electrophilic addition

Answer 21

the first step involves addition of an electrophile

Question 22

nucleophilic addition

Answer 22

the first step involves addition of a nucleophile. involves an additional “work-up” step that involves adding a final proton transfer

Question 23

elimination reaction

Answer 23

atoms are eliminated from the reactant. example: base catalyzed elimination

Question 24

substitution reaction

Answer 24

one (or more) atoms in the reactant are replaced by another

Question 25

radical substitution

Answer 25

the reaction is a radical process and a radical is generated

Question 26

nucleophilic (alkyl) substitution

Answer 26

a nucleophile "attacks" an electrophilic centre

Question 27

nucleophilic acyl substitution

Answer 27

the electrophilic centre can also be associated with a double bond

Question 28

spectroscopy can be used to:

Answer 28

rapidly determine the structure of the molecule by observing interaction of "light waves" with molecules

Question 29

X-rays:

Answer 29

scattered by molecule, gives info about bond length and angles

Question 30

radio waves:

Answer 30

make nuclei resonate-Nuclear Magnetic Resonance (NMR) spectroscopy can be used to determine the carbon skeleton of the molecule

Question 31

infrared rays:

Answer 31

vibrational, are absorbed and give information about the types of bonds in a molecule and the functional groups present in a molecule

Question 32

wavenumbers

Answer 32

frequency unit used in IR (infrared) spectroscopy: wavenumber=1/wavelength in cm

Question 33

electromagnetic radiation in the infrared region corresponds to the energy required to:

Answer 33

excite bond vibrations

Question 34

to be detected/in order for a bond to interact with infrared radiation:

Answer 34

the bond must be polar. the stronger the polarity, the stronger the absorption

Question 35

what are the different types of vibrations?

Answer 35

stretching (symmetric, asymmetric), in-plane bending (scissor, rock), out of plane bending (wag, twist)

Question 36

bands in an IR spectrum correspond to:

Answer 36

frequencies where the molecule is excited by absorption of photon and vibrates