Classify the following compounds as alkanes, alkenes, an alkynes:

C₂H₄, C₃H₄, C₄H₈, C₅H₈, C₃H₈, C₅H₁₂

25 Why is graphite used for making dry cell electrodes but diamond is not? 26 Give the general formula of an: (i) alkane (ii) alkene (iii) alkyne. 27 (i) Friedrich Wohler converted an inorganic compound into an organic compound in the laboratory.

(ii) Write the name and formula of organic compound formed.

27 Give the molecular formula of butane and mention the names of its two isomers. Name one fuel which contains both these isomers.