Week 12

Question 1

When carboxylic acids are put in water…

Answer 1

OH group readily deprotonates to give a carboxylate line plus protons

Question 2

Carboxylic acids react with strong bases

Answer 2

They participate in acid-base reactions, which can go to completion.

Question 3

Zwitterion

Answer 3

Distinctive charges within it but the overall net charge is zero

Question 4

Isoelectric point

Answer 4

the point at which the pH of the amino acid is zwitterion in solution

Question 5

Fatty acids

Answer 5

long chain carboxylic acids (ranges from C8 – C20)

Question 6

Saturated fatty acids

Answer 6

have alkane chain (e.g. coconut oil, animal fats, butter)

Question 7

Monounsaturated fatty acids

Answer 7

contain one double bond (e.g. olive, canola, sesame oils)

Question 8

Polyunsaturated fatty acids

Answer 8

contain two or more double bonds (e.g. sunflower, soybean oils)

Question 9

When you esterify long chain fatty acids you end up with…

Answer 9

Fats (solid) and oils (liquid) are esters of fatty acids and an alcohol

Question 10

It is possible to make an ester by reacting a carboxylic acid and an alcohol directly

Answer 10

True, But needs a catalyst (H+) and sometimes heat.
Water is liberated

Question 11

Making amides by reacting carboxylic acids directly with amines generally works

Answer 11

False, because amine groups are quite basic, protonation occurs and you end up with a salt

Question 12

Fatty acid components (saturated)

Answer 12

palmitic acid
stearic acid
arachidic acid

Question 13

Fatty acid components (unsaturated)

Answer 13

palmitoleic acid
aleic acid

Question 14

Saturated fats and unsaturated fats with an E double bond

Answer 14

pack well together and tend to be solids at room temp

Question 15

unsaturated fats with a Z double bond

Answer 15

pack less well and are liquid at room temp

Question 16

Soap

Answer 16

Key ingredients:
* sodium salts of long chain fatty acids.

The combination of a hydrophobic hydrocarbon chain and polar hydrophilic carboxylate group pulls grease into water.

Question 17

how soap cleans

Answer 17

1. When molecules are put in water, they aggregate together to form micelles
2. Water is excluded from the centre of the structure
3. Water interacts strongly with the carboxylate groups
4. Fatty dirt particles gets trapped within the centre of micelle (hydrophobic) which is easily washed away

Question 18

how soap is made

Answer 18

heating fats with concentrated sodium hydroxide (NaOH).

Question 19

Synthetic detergents

Answer 19

Does not contain a carboxyl group
* Instead uses a polar group such as sulphate
* Cheaper to make and have stronger grease penetrating power

Question 20

soap vs. covid

Answer 20

breaking up the lipid bilayer and and virus components removed in micelle

Question 21

The chemistry of alcohols is dominated by

Answer 21

the electronegativity of O
* Attached C and H are electron-deficient as a result of being bonded to O

Question 22

OH group

Answer 22

polar and engages in hydrogen bonding

Question 23

An alcohol does not readily accept H+

Answer 23

• Equilibrium lies to the left
• It takes a very strong base to remove the H

Question 24

Phenols

Answer 24

lower pKa values than alcohol, therefore much more acidic
* when placed in water - deprotonation of the OH group occurs to form a hydronium ion

Question 25

Conjugation

Answer 25

3 or more p-orbitals in an uninterrupted sequence can share electrons like an electric circuit

Question 26

Aromaticity requires three things:

Answer 26

1. Aromatic systems are conjugated, but also
2. Conjugated system is cyclic, and
3. Conjugated system contains 4n+2 𝛑 electrons

Question 27

Amines

Answer 27

Amines contain ≥ 1 organic group(s) bonded to nitrogen
* general formulae RNH2, R2NH, R3N
* are BASIC

Question 28

Amines can form hydrogen bonds

Answer 28

Nitrogen: 1s2 2s2 2p3
* 3 covalent bonds, leaving a lone pair
* sp3 hybridised, with a lone pair in one orbital
* Good at H-bonding

Question 29

Carboxylic acids can be converted to acyl chlorides (or acid chlorides) with

Answer 29

a specific chlorinating reagent, thionyl chloride (SOCl2)

Question 30

Acyl chlorides

Answer 30

very reactive and easily transformed into a range of other things,
* e.g. esters and amides

Question 31

Acyl chlorides react with ____ to make esters

Answer 31

Alcohols

Question 32

Acyl chlorides react with ____ to make amides

Answer 32

Amines

Question 33

Making esters from carboxylic acids

Answer 33

slower reaction, needs a catalyst (H+) and sometimes heat

Question 34

Amides are important components of many pharmaceuticals, including

Answer 34

Lidocaine, Penicillin, Paracetamol, Prilocaine

Question 35

acetyl coenzyme A

Answer 35

molecular crane for the delivery of acetate and other groups in biosynthetic processes

Question 36

Hydrolysis

Answer 36

chemical reaction in which a molecule of water breaks one or more chemical bonds

Question 37

Oxidation

Answer 37

Oxidation of organic molecules increases their O content or decreases their H content

Question 38

Oxidation in biology

Answer 38

Oxidation of a molecule makes it more soluble and easier to excrete from the body

Question 39

Reduction of carboxylic acids

Answer 39

carried out using a strong reducing agent, such as lithium aluminum hydride (LiAlH 4).
* NaBH4 is usually used as it is cheaper and easier to handle
* LiAlH4 is more reactive