Question
Question: A mixture of white bauxite powder and coke is heated in nitrogen gas very strongly. Which of the fol...
A mixture of white bauxite powder and coke is heated in nitrogen gas very strongly. Which of the following products will be obtained?
(A) Al2O3,C2N2
(B) Al(NO3)3 ,CO
(C) AlN, Si vapour, CO
(D) Al2(CO3)3,N2O
Solution
Bauxite is the most important ore of aluminum which contains only 30–54% alumina, Al2O3; the rest is a mixture of silica, various iron oxides, and titanium dioxide along with trace amounts of zinc, phosphorous, nickel, vanadium etc.
Complete step by step answer: Bauxite is a rock formed from a reddish clay material called laterite soil and is most commonly found in tropical or subtropical regions. Bauxite consists primarily of aluminum oxide compounds (alumina), silica, iron oxides and titanium dioxide.
Coke is a grey, hard, and porous fuel with a high carbon content and few impurities, made by heating coal or oil in the absence of air—a destructive distillation process. It is an important industrial product, used mainly in iron ore smelting, but also as a fuel in stoves and forges when air pollution is a concern.
On heating bauxite with coke and nitrogen, the following reaction takes place:
Al2O3+3C+N2→2AlN+3CO
SiO2+2C→Si+2CO
Thus, aluminium nitride, carbon monoxide and silicon vapour are formed.
Therefore, the correct option is the C option.
Note: Bauxite ore is the world's primary source of aluminum. The ore must first be chemically processed to produce alumina (aluminum oxide). Alumina is then smelted using an electrolysis process to produce pure aluminum metal. The chemical formula of bauxite is Al2H2O4 .