This question is about unsaturated hydrocarbons.
Compound A (2-methylbuta-1,3-diene) and compound B (penta-1,3-diene) are structural isomers. Compound A has a lower boiling point than compound B. Suggest why.
Compound C, CH3CH2CH=CHCH2OH\text{CH}_3\text{CH}_2\text{CH}=\text{CHCH}_2\text{OH}CH3CH2CH=CHCH2OH, exists as cis and trans stereoisomers.
Identify the systematic IUPAC name for compound C.
Define the term stereoisomers.
Explain how the structures of the cis and trans isomers of compound C differ in spatial arrangement.
Compound D, (CH3)2C=CHCH3\text{(CH}_3\text{)}_2\text{C}=\text{CHCH}_3(CH3)2C=CHCH3, reacts with hydrogen chloride, HCl\text{HCl}HCl, by electrophilic addition. A mixture of two organic compounds, E and F, is formed.
Suggest how an HCl\text{HCl}HCl molecule can act as an electrophile.
Give the IUPAC names of the two addition products, E and F.
State which of E and F is the major organic product, and explain your answer in terms of carbocation intermediate stability.
Limonene, C10H16\text{C}_{10}\text{H}_{16}C10H16, is a naturally occurring unsaturated cyclic hydrocarbon containing two carbon-carbon double bonds.
Reaction of 272 mg272\text{ mg}272 mg of limonene with hydrogen gas produces a saturated cyclic hydrocarbon. Calculate the volume of hydrogen gas, in cm3\text{cm}^3cm3 and measured at room temperature and pressure (RTP), needed to completely react with this mass of limonene. (Take the molar volume of gas at RTP as 24000 cm3 mol−124000\text{ cm}^3\text{ mol}^{-1}24000 cm3 mol−1). Show your working.
Lycopene is a naturally occurring, acyclic unsaturated hydrocarbon found in tomatoes. A 0.00500 mol0.00500\text{ mol}0.00500 mol sample of lycopene reacts completely with 1.56 dm31.56\text{ dm}^31.56 dm3 of hydrogen gas, measured at RTP, to form a saturated hydrocarbon. Using molecular formulas, construct a balanced equation for this reaction. Include relevant calculations and reasoning.
