C2 2017

Question 1

19a Write an equation for the reaction of concentrated nitric acid with concentrated sulfuric acid to form the species that reacts with nitrobenzene

Answer 1

HNO3 + H2SO4 -> NO2+ + H3O+ + 2HSO4-

Question 2

19e Give one other practical requirement when placing the plate in the beaker

Answer 2

Solvent depth must be below start line

Question 3

19f Rf value of 1,4-dinitrobenzene greater than 1,2-dinitrobenzene. Deduce the relative polarities of 1,2-dinitrobenzene and 1,4- and why its greater

Answer 3

1,4- less polar
As it has lower affinity to stationary phase

Question 4

20g Explain why polymer U is not biodegradable

Answer 4

Non polar C-C bonds cannot be attacked by nucleophiles