Question

A brown colour soild X when mixed with another soild Y no reaction takes place at normal temperature when this mixture is ignited with megnisium ribbon reaction takes place which gives two products A and B A is a metal which settles down in molten state and B is a compound which floates over A. This exothermic reaction

Answer 1

The brown coloured solid X is Ferric oxide( Fe₂O₃ ) and the solid Y is Aluminium (Al) . When this reaction mixture is heated with a burning magnesium ribbon , Aluminium reacts with iron oxide to produce iron metal with the evolution of a lot of heat. Due to this heat, iron metal is produced in the molten state and Aluminium oxide(Al₂O₃) formed floats over it. This is thermite reaction. The chemical reaction is :

Fe₂O₃(s) + 2Al(s) $\stackrel{Mg}{\to }$ 2Fe (l) + Al₂O₃(s) + Heat

Thus X = Fe₂O₃
Y = Al
A = Fe
B = Al₂O₃