2. TITANIUM DIOXIDE
• Preparation
Titanium dioxide (titania) is prepared by heating rutile or
ilmenile with carbon in a stream of chlorine. The volatile TiCl4
formed is oxidised to TiO2 with O2
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 Cl2 or CCl4 vapours over TiO2.TiCl4 is formed.
• Equation
• When heated with C, Ca or Al.TiO2 is reduced to Ti metal
• Equation
• TiO2 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 BaSO4 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.H2SO4
• Equation
• When heated strongly with boron and carbon,
it forms boride and carbide respectively.
• Equation
• When heated with carbon in a current of Cl2,
ThCl4 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 MoO3
• 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 6000C
• Properties
• V2O5 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
• , V2O4 is obtained.
• Al-power reduces V2O5 to V-metal
• When V2O5 is heated can metal, V2O5 gets reduced to V-metal
• When heated with carbon at high temperature, vanadium carbide is
obtained.
• When Cl2 gas is passed over a mixture of V2O5 and carbon VOCl3 is formed.
10. Uses
• V2O5 is used as a contact catalyst.
• Inthe oxidation of SO2 to SO3during the
manufacture of H2So4.
• 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 NH4
+ 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 3700C in Cl2, PtCL4 is formed.
• When H2S is passes into a hot solution of H2PtCl6 platinic sulphide is
obtained as a black ppt.
• When a hot solution of H2PtCl6 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 H2PtCl6 is used as a tonner in
photography.
• It is used in the gravimetric estimation of
organic bases.