Paper 2- 2017

Question 1

Calculate mass of x produced from 25.2g of Y assuming 75% yield? Mr of Y=122.9 and Mr of X=59

Answer 1

Moles Y: 25.2/122.9= 0.2050447518
Moles X: 0.2050447518 x 0.75=0.154
Mass= 0.154 x59= 9.07g

Question 2

Distinguish separate samples of 2 stereoisomers

Answer 2

Rotates plane polarised light by equal amounts in opposite directions

Question 3

Why reaction produces racemic mixture

Answer 3

Reactants has planar group that is approached equally by both side s by attacking species which produces equal amounts of enantiomers

Question 4

Justify if tot vol doesn’t need to be measured to give correct value for kc

Answer 4

Vol would cancel out
Equal no of moles on either side

Question 5

Name of amide produced between CH3CH2COCl and CH3CH2NH2

Answer 5

N-ethylpropanamide

Question 6

Test for bromine

Answer 6

AgNO3- cream ppt

Question 7

Equation for conc HNO3 and H2SO4

Answer 7

HNO3+ 2H2SO4–> NO+ + H3O+ +2HSO4-

Question 8

Mechanism between nitrobenzrne to form 1,3-diniyrpbenzebe

Answer 8

Electrophylic sub

Question 9

What determines distance travelled by spot on TLC

Answer 9

Solubility in moving phase and retention in stationary phase

Question 10

Relative polarities of 1,2 and 1,4 and why 1,4 has greater polarity

Answer 10

1-2 is more polar
1-4 less attracted to polar plate

Question 11

Different solvent used,would RF be greater?

Answer 11

Yes as solvent is more polar. Polar isomer os more soluble/more attracted to solvent

Question 12

Why polymer is non biodegradable

Answer 12

Strong/ non polar C-C bond cannot be hydrolysed or attached by nucleophile. Only polar ester group can be attacked.

Question 13

Methyl benzene three step synthesis

Answer 13

Free radical sub: Cl2 in uv light to form halogenalkane
Nuc sub: halogenoalkane with KCN in ethanol and water mixture to form nitrile
Reduction/Nuc add- LiAlH4 in ether to for 1° amine