mindmap flashcards

Question 1

what member of the em spectrum is used in nmr spectroscopy

Answer 1

radio waves

Question 2

what is a pharmacaphore

Answer 2

the section of medicine that creates an effect

Question 3

what is a chromophore

Answer 3

the section of a molecule that produces a colour in the compound - found where there is a conjugated system

Question 4

what is the hybridisation of alkanes

Answer 4

sp3

Question 5

what is the hybridisation of alkenes

Answer 5

sp2

Question 6

what is the hybridisation of alkynes

Answer 6

sp

Question 7

what is the hybridisation of benzene

Answer 7

sp2

Question 8

what do we call the two types of nucleophilic substitution

Answer 8

Sn1 and Sn2

Question 9

which mechanism do primary haloalkanes react with

Answer 9

sn2

Question 10

which mechanism do tertiary haloalkanes react with

Answer 10

sn1

Question 11

which mechanism do secondary haloalkanes react with

Answer 11

sn2

Question 12

what is the intermediate in an sn2 mechanism

Answer 12

a transition state

Question 13

what is the intermediate in an sn1 mechanism

Answer 13

a carbocation, where the group has been removed and leaves the carbon with a positive charge

Question 14

what is a dative covalent bond

Answer 14

a covalent bond where the shared pair of electrons both came from one species in the bond

Question 15

what is a ligand

Answer 15

something that binds to a central ion

Question 16

what is a homogenous catalyst

Answer 16

a catalyst that is in the same state as the reactants

Question 17

what is a heterogenous catalyst

Answer 17

a catalyst that is in a different state to the reactants

Question 18

what is meant by ligand field splitting

Answer 18

the binding of the ligand causes a shift in the energy of the d orbitals. the orbitals become no longer degenerate and electrons can be promoted into the split orbital

Question 19

why are many transition metal complexes coloured

Answer 19

absorption of energy to move electrons to the higher d orbital is in the visible range so transition metals show the colour on the opposite of the colour wheel

Question 20

explain the role of d orbitals in catalysis

Answer 20

unpaired or unfilled d orbitals can allow intermediate states to form in the catalytic pathway

Question 21

what is an indicator

Answer 21

a substance with a clear colour change caused by distinct colours on each side of an equlibirium

Question 22

outline the steps for producing a calibration curve in colourimetry

Answer 22

• a range of samples are prepared of known concentration
• colorimeter readings are taken with the wavelength that is most appropriate - ie has the greatest absorbance
• dilutions to get samples are generally linear, but can be serial to give range.

Question 23

why is heating under reflux used

Answer 23

prevents volatile reactants or products escaping while heating

Question 24

why is distillation used

Answer 24

can be used to assess purity by looking at the point at which a substance is separated by distillation

Question 25

what is the purpose of recrystallisation

Answer 25

to purify an impure solid

Question 26

describe the steps involved in recrystallisation of an organic compound

Answer 26

- dissolving an impure solid gently in a minimum volume of hot solvent - hot filtration of the resulting mixture to remove any insoluble impurities - cooling the filtrate slowly to allow crystals of the pure compound to form, leaving insoluble impurities dissolved in the solvent - filtering, washing and drying the pure crystals

Question 27

if the partition coefficient is high, which layer is the solute most soluble in

Answer 27

upper solvent

Question 28

describe the process of solvent extraction

Answer 28

- the solvent used must be immiscible with the liquid mixture or solution - the solvent must also be one which the solute is more soluble in than the liquid mixture or solution, volatile enough to allow the solute to be obtained by evaporation of the solvent, and unreactive with the solute - extracting with multiple small volumes of solvent will extract a greater volume of solvent than a single extraction