Paper 3 Flashcards
1
Q
Finding the identity of the cyclic hydrocarbon
A
1) volume of hydrocarbon: 25cm^3
2) volume of CO2: 125cm^3
3) ratio of hydrocarbon to CO2: 1:5
4) therefore x = 5
5) (25 + oxygen available) - (125 + oxygen not used) = 75
6) hence the volume of oxygen reacting is 175
7) ratio of hydrocarbon to CO2 to water is: 1:5:7
8) x + (y/4) = 7
9) y = 8
2
Q
remember, on a chlorine ion electrophile
A
there is a lone pair
3
Q
limonene question
A
- RFM of limonene: 136
- moles of bromine: 6.12 x 10^-3
- molar ratio of limonene to bromine: 1:2
- moles of limonene: 3.06 x 10^-3
- percentage: 83.2%
4
Q
which of the skeletal formulae has the molecular formula C6H10
A
C
5
Q
conditions for alkene -> alcohol
A
- steam
- 300-600 degrees C
- 70atm
conc. H3PO4 catalyst
6
Q
include
A
TWO repeat units
7
Q
NMR spectra
A
- X is CH3CH(OH)CH2CH3
- Y is CH3COCH2CH3
- explain both numbers of hydrogen environments
- draw them out and circle hydrogen environments and splitting patterns (include numbers)
8
Q
devise an experiment:
A
- need ethanol solution
- need silver nitrate solution
- need to add equal amounts of each halogenoalkane
- need to calculate time taken for precipitate formation
- need to keep temperature constant through water-bath
9
Q
trend in hydrolysis rates
A
- iodo greater than bromo, greater than chloro
- because C-I bond is weakest
10
Q
nucleophilic substitution
A
- occurs in both
- SN1 is for tertiary alcohols - it has a carbocation intermediate, and therefore only one species in the rate determining step
- SN2 is for primary alcohols - it has a transition state and therefore two species in the rate determining step
- diagrams !
11
Q
drawing your own NMR
A
- 3 hydrogen environments
- one singlet (3.0)
- one triplet (0.9)
- one quartet (3.6)
- splitting occurs due to the (n+1) rule
- areas 3:2:1
- draw it to help out!
