inorganic compounds

To learn about inorganic compound

1. UNIT -II INORGANIC COMPOUNDS

2. TITANIUM DIOXIDE Preparation Titanium dioxide ( titania ) is prepared by heating rutile or ilmenile with carbon in a stream of chlorine. The volatile TiCl 4 formed is oxidised to TiO 2 with O 2 Properties It is an amphoteric oxide. It dissolves in acids to form oxo salts. It also dissolves in alkalies forming titanates . Equation Om passing dry Cl 2 or CCl 4 vapours over TiO 2 .TiCl 4 is formed. Equation When heated with C, Ca or Al.TiO 2 is reduced to Ti metal Equation TiO 2 dissolves in HF to form hydrofluotitanic acid Equation

3. Uses Because of its high opacity and covering powder, white pigment in paints under the name titan white. Mixed with BaSO 4 it is sold under the name titanox . Whitener in cosmetics (e.g. face powder, vanishing cream, tooth paste). It is used as an additive in the manufacture of fibre glass. Enamelling porcelain goods. Manufacture of gas mantles, are lamp electrodes, glazes, artificial gems and non- greasable paper. Soften rubber and coating the surface of leather (white leather).

4. THORIUM OXIDE Preparation Thorium oxide or thoria exists in amorphous as well as crystalline forms. The amorphous form is obtained by heating thorium ritrate . Equation The crystalline form can be obtained by fusing thorium fluoride with sodium carbonate. Equation

5. Properties Thoria is slightly soluble in water and dilute acids but readily soluble in hot conc.H 2 SO 4 Equation When heated strongly with boron and carbon, it forms boride and carbide respectively. Equation When heated with carbon in a current of Cl 2 , ThCl 4 is precipitated. Equation

6. Uses Because of its resistance to high temperature, thoria mixed with 1% ceria is used in the preparation of gas mantles. Refractory material. A contact catalyst in many organic reactions. It is employed in welding operations and also in medicines. An additive to tungsten filament. On account of its high absorptive power for X-rays, it is used in X-ray diagnostic work. Ceramic industry. Thoria with traces of ceria has been used for search lights, head lights of motor cars etc.

7. AMMONIUM MOLYBDATE Preparation Ammonium molybdate is obtained by dissolving molybdenum trioxide in dilute ammonia solution and evaporating the resulting Properties On heating, ammonium molybdate is decomposed to MoO 3 With phosphates, it gives an yellow ppt of ammonium phosphomolybdate in the presencse of nitric acid With arsenic salt, it forms yellow ammonium arsenomolybdate in the presence of nitric acid. Solution to crystallisation.

8. Uses Ammonium molybdate is an analytical reagent used to detect phosphates and arsenates. It is used as a catalyst for dehydrogenation and desulphurisation in petroleum and coal industries.

9. VANADIUM PENTOXIDE Preparation Vanadium pentoxide is formed when ammonium metavanadate is heated to 600 C Properties V 2 O 5 is an amphoteric oxide It dissolves in strong acids forming oxo salts With alkalies , it forms a series of vanadates . Vanadium pentoxide on reduction yields lower oxides , V 2 O 4 is obtained. Al-power reduces V 2 O 5 to V-metal When V 2 O 5 is heated can metal, V 2 O 5 gets reduced to V-metal When heated with carbon at high temperature, vanadium carbide is obtained. When Cl 2 gas is passed over a mixture of V 2 O 5 and carbon VOCl 3 is formed.

10. Uses V 2 O 5 is used as a contact catalyst. Inthe oxidation of SO 2 to SO 3 during the manufacture of H 2 So 4 . In the oxidation of anthracine to anthraquionone (raw material for dyes ). In the oxidation of phenanthrene to phenathraquinone . In the oxidation of ethyl alcohol to acetaldehyde Preparation of vanadium glass which protects the eyes against harmful rays and are used in textile store windows. Preparation of ferro -vanadium alloy which is u sed as a segvenger in the manufacture of steel.

11. SODIUM COBALTINITRITE Preparation It is prepared by mixing well cooled solutions of cobalt nitrate and sodium nitrite and acidifying the mixture with glacial acetic acid. Properties It gives an yellow ppt with ammonium or potassium salt Uses Sodium cobaltinitrite is used for the detection estimation of K + and NH 4 + ions.

12. CHLOROPLATINIC ACID Preparation It is prepared by the action of aqua regin on platinum metal. Properties With alkalies and ammonia, chloropolatinic acid forms stable salts called chloroplatinates . With organic bases, it forms stable crystalline compounds When reduced with formic acid, platinum black is obtained . When heated to 370 C in Cl 2 , PtCL 4 is formed . When H 2 S is passes into a hot solution of H 2 PtCl 6 platinic sulphide is obtained as a black ppt . When a hot solution of H 2 PtCl 6 is treated with KI, platinic iodide is formed.

13. Uses Chloroplatinic acid is used in the determination of molecular weight of organic bases. It is used in the preparation of spongy platinum. A solution of H 2 PtCl 6 is used as a tonner in photography. It is used in the gravimetric estimation of organic bases.