Question

(a) Give a chemical test to distinguish between saturated and unsaturated hydrocarbons. 

(b) (i) Name the products formed when ethanol burns in air. ‘ 

(ii) What two forms of energy are liberated on burning alcohol? 

(c) Why is the reaction between methane and chlorine considered a substitution reaction?

Answer 1

(a) Add bromine water. saturated hydrocarbons do not react wheres unsaturated hydrocarbon will decolourise bromine water.

(b) CO₂ and H₂O are formed.

C₂H₅OH (l) +3O₂(g)→ 2CO₂(g) +3H₂O(l) +Heat + light

(ii) Heat energy and light energy

(C) It is because 'Cl' atom substitures 'H' atom of methane to from chloromethane and hydrogen chloride.