Chemistry Form Six Pre-Mock Joint Examination 2026 – Senkolink
CHEMISTRY FORM SIX PRE-MOCK JOINT EXAMINATION 2026 – SENKOLINK
QUESTIONS
9 (a)
(i) Sulphonation is the reaction between benzene and concentrated sulphuric
acid, but in this reaction Lewis acid is not required. Why?
(ii) Methylation of benzene followed by nitration give two
products but nitration followed by methylation give out one product. Account
for this observation. Equation is necessary.
(iii) In which case the rate of sulphonation is higher
“nitrobenzene or phenylamine”? Equation is necessary.
(iv) Brominating benzene takes place in the presence of
Lewis acid while that of hydroxybenzene does not require the presence of Lewis
acid. Why?
(b) Convert phenol into:
(i) Salicylaldehyde
(ii) Picric acid
(iii) Aspirin
(c) Which one of the following pair undergoes SN1
substitution reaction faster and why?
CH₃CH₂Br and (CH₃)₃CBr.
10 (a)
(i) Why can aryl halide not be prepared by reaction of phenol with hydrochloric
acid in the presence of zinc chloride?
(ii) Phenol has higher boiling point than toluene. Why?
(iii) Both O-nitrophenol and O-cresol are more acidic. Why?
(b) Give simple chemical tests to distinguish the following
pairs of compounds:
(i) Propanal and Propanone
(ii) Phenol and benzoic acid
(iii) Benzaldehyde and acetophenone
(iv) Acetophenone and benzophenone
