Write the molecular formula of ethene and also give three succeeding members with their names.

An organic compound X of molecular formula C₂H₄O₂ turns blue litmus to red and gives brisk effervescence with Na₂CO₃ and NaHCO₃. Identify X and name of the gas responsible for effervescence.

(i) Why does carbon form largest number of compounds? Give two reasons.

(ii) Why are some of these called saturated and the other unsaturated compounds?

(iii) Which one of these two is more reactive and why?

Give reasons for the following.

(i) Unsaturated hydrocarbons show addition reaction.

(ii) Alcohol supplied for industrial purpose is mixed with copper sulphate.

Name the following compounds.

(i)

(ii)