Five (5) hydrocarbon molecules (J, K, L, M, and N) have the same chemical formula, CH8.
Molecules J, K, and L can react with bromine, Br, in the dark using dichloromethane, CH2Cl2 as a
solvent. Among these three, J has the lowest boiling point, followed by K and then L. All three
molecules (J, K, and L) can react with hydrogen bromide, HBr. Interestingly, K and L produce the
same optically active product when reacting with HBr.
The remaining two molecules, M and N, can only react with bromine, Br2 if light is present.
Interestingly, all the carbon atoms in molecule M are secondary carbons.
a) Draw the structural formulas for all five isomers (J, K, L, M, and N). Explain your reasoning for each
structure based on the information provided. (8 marks)
b) Explain why molecule J has the lowest boiling point among J, K, and L. (1 mark)
c) Write the balanced chemical equations for the reaction between isomers L with HBr. (1 mark)
d) Show the reaction mechanism (step-by-step process) for how molecule L reacts with HBr. (3 marks)
e) State a chemical test (other than using Br2 in the dark) to distinguish between molecules J and M.
Write the balanced chemical equation and describe the expected observations. (5 marks)
f) Identify which isomer of CH, exhibits geometrical isomerism. Draw the structures of both cis and
trans isomers for this molecule. (2 marks)