AQA AS CHEMISTRY 7404 2 ORGANIC AND PHYSICAL CHEMISTRY TEST PAPER 2026 FULL MARK SCHEME ANSWERS

AQA AS CHEMISTRY 7404 2 ORGANIC AND
PHYSICAL CHEMISTRY TEST PAPER 2026
FULL MARK SCHEME ANSWERS

⩥ How can you tell that the mechanism will be nucleophilic
substitution? Answer: 1) The halogenoalkane is primary or secondary


and


2) The product is not an alkene.


and


3) If there is a hydroxide ion, it will be cold and in water.


⩥ A species (called Y) has a lone pair of electrons and is being reacted
with a halogenoalkane to produce something that is not an alkene. What
is Y acting as? Answer: A nucleophile


⩥ If sodium (or potassium) hydroxide is dissolved in cold water and
mixed with a halogenoalkane. What is it acting as? Answer: A
nucleophile

, ⩥ During nucleophilic substitution, where must the arrows be drawn?
Answer: 1) From the middle of the lone pair to the partial positive
charge


2) From the middle of the C-X bond to the halogen atom


3) For ammonia there is an extra step. The arrow must be drawn from
the middle of the N-H+ bond to the nitrogen atom.


⩥ Place the C-X bonds in order of how quickly they can undergo
nucleophilic substitution (start with the fastest) Answer: 1) C-I (fastest
nucleophilic substitution reactions)


2) C-Br


3) C-Cl (slowest nucleophilic substitution reactions)


4) C-F (unreactive so cannot undergo nucleophilic substition)


⩥ What are the different compounds that can be made from a
halogenoalkane using nucleophilic substitution? Answer: 1) Primary
amine → Secondary amine → Tertiary amine


2) Alcohol → aldehyde → carboxylic acid