question_answer

                        No reaction takes place when granules of a solid A are mixed with a powder of solid B. However when the mixture is heated, a reaction starts with evolution of much heat and produce liquid C and solid D. This reaction is sometimes used for making metals for ready use in odd places. (a) Based on this information, make assumptions about A and B and corresponding deductions about C and D and write a balanced chemical equation for the reaction. Include in the equation chemical equation about physical states of the reactants and products, need of heating for starting the reaction being exothermic. (b) Name two types of chemical reactions to which this reaction can belong.

Answer:

                     (a) Solid A is iron (III) oxide, . Solid B is aluminium powder, Al. Initially the heating of the reactants is must, as the reactants (solid) need to be melted. This reaction is used for joining railway tracks and machine parts.                                         (2) (b) This reaction is a displacement as well as oxidation-reduction reaction.                         (1)