Module 4

Question 1

Electrophile

Answer 1

atom/group of atoms that is attracted to an electron-rich centre - accepts electron pair to form new covalent bond

Question 2

Electrophilic Substitution

Answer 2

Substitution reaction where an electrophile is attracted to an electron-rich centre or atom, where it accepts a pair of electrons to form a new covalent bond

Question 3

Reaction Mechanism

Answer 3

Series of steps that make up the overall reaction

Question 4

REFLUX

Answer 4

Continuous evaporation and condensation to prevent volatile reagents escaping

Question 5

Curley arrow

Answer 5

Movement of a pair of electrons

Question 6

Phenol

Answer 6

-OH group directly bonded to a benzene ring

Question 7

Uses of pheno

Answer 7

Producing plastics (polymers), antiseptics, disinfectants and resins for paints

Question 8

How does an amine act as a base?

Answer 8

Ammonia has a lone pair of electrons on the nitrogen atom which can be donated to the proton forming a dative covalent bond - so has accepted the H+ proton

Question 9

Aliphatic

Answer 9

Hydrocarbon group with carbons in a chain

Question 10

Aromatic

Answer 10

Hydrocarbon group containing a benzene ring

Question 11

Functional Group

Answer 11

Part of an organic molecule responsible for its reactions

Question 12

Electronegativity

Answer 12

Measure of attraction of a bonded atom for the pair of electrons in a covalent bond

Question 13

Aldehydes

Answer 13

Carbonyl group at start of chain

Question 14

Ketones

Answer 14

Carbonyl group in middle of chain

Question 15

Nucleophile

Answer 15

Atom/ group of atoms attracted to an electron-deficient centre, where it donates a pair of electrons to form a new covalent bond

Question 15

Esterification

Answer 15

Reaction of an alcohol with a carboxylic acid to produce an ester + water in a condensation reaction

Question 16

Hydrolysis

Answer 16

Reaction with water/OH- ions which breaks a chemical compound into two - reverse of esterification

Question 17

Formation of an Acid Anhydride

Answer 17

Forms by removal of H2O molecule from two identical carboxylic acid molecules

Question 18

Tryglyceride

Answer 18

Triester of glycerol (propan-1,2,3-triol) and 3 fatty acid molecules

Question 19

Fatty acids

Answer 19

Long-chain carboxylic acids - hydrocarbon chain can be SATURATED (no double bonds) or UNSATURATED (one or more double bonds)

Question 20

Zwitterion

Answer 20

Dipolar ionic form of amino acid that is formed by donation of an H+ ion from carboxyl group to amino group. As both charges are present, no overall charge

Question 21

Isoelectric Point

Answer 21

The pH value at which amino acid exists as a zwitterion

Question 22

Hydrolysis

Answer 22

Breaking of a bond by a reaction with water - catalysed by acid or alkali

Question 23

Peptide

Answer 23

Compound of amino acids linked by peptide bonds

Question 24

Condensation Reaction

Answer 24

Two small molecules react together to form a larger molecule with the elimination of a small molecule like water

Question 25

Stereoisomers

Answer 25

Species with the same structural but with a different arrangement of atoms in space

Question 26

How are alkenes stereoisomers?

Answer 26

- lack of rotation abou C=C double bond | - if carbon in double bond have different atoms/ groups of atoms attached

Question 27

Optical isomers (enantiomers)

Answer 27

Stereoisomers that are non-superimposable mirror images about an organic chairal centre

Question 28

Chiral centre

Answer 28

4 different atoms/groups of atoms attached to a central carbon

Question 29

Racemic mixture

Answer 29

Lab prepared chiral molecules that contain an equal split of enantiomers

Question 30

Condensation

Answer 30

Reaction where two small molecules react together to form a larger molecule, with the elimination of a small molecule eg.water

Question 31

Biodegradable polymer

Answer 31

Polymer that breaks down completely into CO2 and H2O

Question 32

Degradable Polymer

Answer 32

Polymer that breaks down into smaller fragments when exposed to light, heat or moisture

Question 33

Chromotography

Answer 33

An analytical technique that separates out components in a mixture between a mobile phase and a stationary phase

Question 34

Phase

Answer 34

Physically distinctive form of a substance eg the solid, liquid and gaseous states of ordinary matter

Question 35

Mobile phase

Answer 35

Where the molecules can move - always a liquid or a gas

Question 36

Stationary phase

Answer 36

Where molecules can't move (may be solid eg TLC or either liquid or solid on solid support eg GC)

Question 37

Adsorption

Answer 37

A solid holds molecules of gas or liquid or solute as a thin film on the surface of a solid or liquid

Question 38

Rf value(TLC)

Answer 38

Shows how far a component has moved compared with the solvent front: Rf value = Distance moved by component/ Distance moved by solvent front

Question 39

Retention time (GC)

Answer 39

Time for a component to pass from the column inlet to the detector

Question 40

MS-GC

Answer 40

Separated components are directed into a mass spectrometer instead of a detector

Question 41

NMR spectroscopy

Answer 41

Intercation of materials with the low-energy radio-frequency region of the electromagnetic spectrum Requires: a strong magnetic field applied using electromagnet and low-energy radio-frequency radiation

Question 42

Chemical shift

Answer 42

A scale comparing the frequency of an NMR absorption with the frequency of the reference peak of TMS at 0shift

Question 43

TMS

Answer 43

Tetramethylsilane - the reference signal from a standard compound (TMS) against which chemical shift is measured relative to. Chemical shift of TMS is 0ppm

Question 44

MRI

Answer 44

NMR spectroscopy is the same technique using in MRI 'Magnetic Resonance Imaging' to obtain diagnostic information about internal structures in body scanners