from N and H as shown by the following reactions. N +3H 2NH In this process, Fe is the catalyst and Mo is a promoter. The surface of the Fe catalyses the reaction. In the hydrogenation of oils to obtain vanaspathi, Nickel is used as a catalyst.
Nickel surface catalyses the reaction. vegetable oil+H vanaspathi Ni catalyst 473K . Qualitative analysis When blue litmus solution is added to Al + ion, a red coloration is seen due to the acidic nature of the solution. Addition of ammonium hydroxide to it gives a blue lake.
This is due to the adsorption of blue colour litmus compound on the surface of Al (OH) Which is formed during the addition of NH OH . Medicine: Drugs cure diseases by adsorption on body tissues. . Concentration of Ores of metals Sulphides ores are concentrated by a process called froth flotation in which light ore particles are wetted by pine oil.
. Mordants and Dyes Most of the dyes are adsorbed on the surface of the fabrics. Mordants are the substances used for fixing dyes onto the fabric. .
Adsorption indicators In the precipitation titrations, the end point is indicated by an external indicator which changes its colour after getting adsorbed on precipitate. It is used to indicate the end point of the titration.