ALPHA-AL2O3 + GAMMA-ALUMINA

For a good quality cement,the ratio of silica ( SiO_2 ) to alumina ( Al_2O_3 ) is between :-

What type of reactions are represented by following equation : Al(OH)3 → Al2O3 + H2O

The rection : Fe_2O_3 + 2Al rarr Al_2O_3 + 2Fe is an example of

Explain the following (i) Excess of carbon is added to zinc metallurgy. (ii) In the elctrolysis of alumina, cryolite is added to alumina. (iii) Coke does not cause reduction of Al_(2)O_(3) . (iv) Gold is soluble in aquaregia, silver is not.

Explain the following (i) Excess of carbon is added to zinc metallurgy. (ii) In the elctrolysis of alumina, cryolite is added to alumina. (iii) Coke does not cause reduction of Al_(2)O_(3) . (iv) Gold is soluble in aquaregia, silver is not.