Acid Base Chemistry

Question 1

Bronsted acid

Answer 1

proton donor

Question 2

Bronsted base

Answer 2

proton acceptor

Question 3

what does the proton ride on in acid base chemistry

Answer 3

the carrier molecule: bases

Question 4

which type of acids dissociate more readily

Answer 4

strong acids

Question 5

what can describe the strength of an acid

Answer 5

the pka value

Question 6

do weak acids want to dissociate

Answer 6

NO - want to stay together

Question 7

what energy for delta G means reactants are favoured? products favoured?

Answer 7

positive energy - reactant favoured

negative energy - product favoured

Question 8

what does high pka value mean? low pka value?

Answer 8

high - weak acid
low - strong acid

Question 9

does a low or high delta G value = a strong acid

Answer 9

low delta g value

Question 10

what does a high delta g value mean

Answer 10

the acid is harder to dissociate = weaker acid

Question 11

are conjugate bases negative or positive charged

Answer 11

negative

Question 12

how can we determine relative acidities of acids

Answer 12

by looking at relative stabilities of conjugate bases

Question 13

what is the strength of a base relative to

Answer 13

its ability to accommodate (stabilize) negative charge

Question 14

what bases can stabilize negative charges

Answer 14

weak bases

Question 15

what bases cannot stabilize negative charges

Answer 15

strong bases

Question 16

do strong conjugate bases mean weak or strong acids

Answer 16

weak acids

Question 17

do weak conjugate bases mean strong or weak acids

Answer 17

strong

Question 18

what are the five factors for determining stability of bases

Answer 18

1. electronegativity
2. atomic size
3. induction
4. hybridization
5. charge delocalization

Question 19

when is electronegativity used to compare strength of conj bases

Answer 19

when bases are in the same row

Question 20

when is atomic size used to compare strength of conj bases

Answer 20

comparing bases in the same column

Question 21

on what atom will a negative charge stabilize the conj base better?

Answer 21

the more electronegative atom

Question 22

what would be a weak and strong acid according to electronegativity

Answer 22

a negative charge on a more electronegative atom stabilizes the charge better so the conj base is weaker and the acid stronger

a negative charge on a less electronegative atom doesn’t stabilizes the charge as well so the conj base is stronger and the acid weaker

Question 22

how does atom size affect the stability of a conj base

Answer 22

large atoms can spread the charge over large volumes compared to smaller atoms so the charge is diluted and a negative charge on large atom = more stable base = weaker base = strong acid

Question 23

how does induction affect stability of conj base

Answer 23

bases with negative charge dispersed over more atoms are more stable than those with charge localized. When electron withdrawing group are closer to the negative charge they have better strength at stabilizing the negative charge. = weaker base = strong acid

Question 24

how does induction occur

Answer 24

through sigma bonds

Question 25

what affects the strength of the induction effect

Answer 25

1. electronegativity of the atoms 2. number of atoms 3. distance of the atoms involved from negative charge

Question 26

how does hybridization affect relative stability of conj bases

Answer 26

a lower energy orbital makes a negatively charged base more stable = weaker base - stronger acid

Question 27

rank the s hybrid orbitals from least energy (most stable) to highest energy (least stable)

Answer 27

sp ---> Sp2 -----> Sp3

Question 28

how does charge delocalization affect the relative stability of conj bases

Answer 28

a base that has more resonance will better stabilize the negative charge = more stable = weak base = strong acid

Question 29

how does induction differ from resonance

Answer 29

induction happens through sigma bonds and resonance through pi bonds

Question 30

how does charged acids differ from neutral acids

Answer 30

charged acids do not have to look at the conj base

Question 31

how does electronegative affect stability of charged acid

Answer 31

a positive charge on a less electronegative atom stabilizes the positive charge better = weak acid = less acidic = strong base a positive charge on a more electronegative atom does not stabilize the positive charge = more acidic = weak acid = strong base

Question 32

how does atomic size affect stability of charged acid

Answer 32

large atoms with a positive charge will be more stable as they can better delocalize positive charge = weaker acid small atoms do not stabilize the positive charge as well = stronger acid

Question 33

how does induction affect stability of charged acid

Answer 33

nearby electronegative atoms can INCREASE the effective positive charge on the atom = positively charged molecules LESS stable = a stronger acid a strong electronegative atom near a positive atom will pull the negative charge away from the positive center = makes positive atom MORE positive = less stable acid = stronger acid

Question 34

how can the strength of a base be quantified

Answer 34

by using the pka of conjugate acid

Question 35

what way does equilibrium tend to shift in reactions

Answer 35

towards the more stable materials (weak acid and base)

Question 36

what indicates how far the equilibrium shifts in acid base reactions

Answer 36

the difference in pka values (larger difference in pka values = more dramatic shift in equilibrium)

Question 37

what is the best way to predict the acid base equilibrium

Answer 37

looking at the charged molecules (determine which is more stable based on the five factors)

Question 38

what form are acids when ph is less than pka

Answer 38

protonated form (acid form)

Question 39

what form are acids when ph is more than pka

Answer 39

in their deprotonated form (conjugate base)

Question 40

what form are acids when ph is equal to pka

Answer 40

a 50/50 mix of the acid forms and conjugate forms

Question 41

what are lewis acids

Answer 41

electron pair acceptor

Question 42

what are lewis bases

Answer 42

electron pair donor

Question 43

compare pka of hydronium and water

Answer 43

hydronium (H3o+) = 0 water = 14

Question 44

compare pka of alcohol and protonated alcohol

Answer 44

protonated alcohol = -3 alcohol = 16

Question 45

what is the stronger acid = alcohol or protonated alcohol

Answer 45

alcohol has higher pka = weaker acid protonated alcohol = has lower pka = stronger acid

Question 46

compare pka of ketone and protonated ketone

Answer 46

ketone = 19 protonated ketone = 16

Question 47

compare pka of ammonium and amine

Answer 47

ammonium = 10 amine = 35

Question 48

compare pka of alkane, alkene and alkyne

Answer 48

alkane = 50 alkene = 43 alkyne = 25

Question 49

what is the pka for mineral aicds (HI, HBr, HCl, H2SO4)

Answer 49

-4

Question 50

what is the pka for carboxylic acid

Answer 50

5

Question 51

electrophile

Answer 51

atom or group that accepts electrons to make bond

Question 52

is a lewis acid a nucleophile or electrophile

Answer 52

electrophile

Question 53

is a lewis base a nucleophile or electrophile

Answer 53

nucleophile

Question 54

nucleophile

Answer 54

an atom or group that donates electrons to form a bond

Question 55

what attracts nucleophiles

Answer 55

electrophiles

Question 56

how do nucleophiles form a new bond

Answer 56

by sharing electron pair with electrophilic site

Question 57

what is the form of an alkoxide

Answer 57

the conjugate base of an alcohol

Question 58

what is the simplest nucleophile

Answer 58

the hydride ion

Question 59

oxidation reaction vs reduction reaction

Answer 59

oxidation - addition of O atom OR removal of hydrogen atoms (2) reduction - addition of 2 hydrogen atoms OR removal of O atom

Question 60

organometallics

Answer 60

organic compounds where carbon is bonded to metal

Question 61

what is a grignard reagent

Answer 61

exposition ethereal (ether) solution of an organic halide (Cl, Br or I) to magnesium metal

Question 62

two types of ethereal solutions for grignard reagents

Answer 62

diethyl ether THF

Question 63

what is the carbon in a grignard reagent

Answer 63

full negative charge on carbon (CARBANION)

Question 64

are carbanions powerful bases or acids

Answer 64

bases

Question 65

what is conjugate acid of carbanions

Answer 65

alkanes

Question 66

when can grignard reagent only be prepared

Answer 66

when functional groups containing acidic hydrogens are NOT present

Question 67

what are some functional groups that will NOT allow grignard reagent to be prepared

Answer 67

1. ketones 2. amine 3. alcohol 4. nitrile 5. nitro group

Question 68

structure of magnesium alkoxide

Answer 68

salt made of magnesium and an alcohol

Question 69

organolithium compounds

Answer 69

prepared by exposing the appropriate alkyl halide to TWO atoms of lithium metal in ether

Question 70

what is produced in organolithium reactions

Answer 70

alkoxide salt before the final alcohol product

Question 71

what are acetylides

Answer 71

carbanions from alkynes

Question 72

are acetylides nucleophilic

Answer 72

YES

Question 73

are nucleophiles associated with homo or lumo

Answer 73

homo

Question 74

are electrophiles associated with homo or lumo

Answer 74

lumo