WAEC Chemistry 2018 Theory — Question 15
Question 15 of 24 from the West African Examinations Council (WAEC) Chemistry 2018 Theory paper, with the correct answer and a full explanation.
Advertisement
3.(a)(i) Draw the structure of the sixth member of the alkene series. (ii) Calculate the relative molecular mass of the sixth member of the alkene series. [H=1, C=12] (iii) State one difference between cracking and reforming in the petroleum industry.
Model answer
(i) The sixth member of the alkene series is heptene, C₇H₁₄ (structure: a 7-carbon chain with one C=C double bond). (ii) Molecular mass = (12×7)+(1×14) = 98. (iii) Cracking involves breaking large hydrocarbon molecules into smaller ones, while reforming involves the re-arrangement of atoms within molecules without necessarily changing their size.
Advertisement
Sign up free to unlock
- Score tracking
- Practice history
- Saved questions
- Progress dashboard
- Personalized sessions
- Weak-topic breakdown
…and/or go further with premium services and No Ads.