State the effect of the following on the reaction 2SO2(g)+O2(g) 2SO3(g)+189.4 kJ at
equilibrium:
(i) Temperature is increased.
(ii) Concentration of SO2 is increased.
(iii) Pressure is decreased.
(iv) Helium is added at constant pressure.
(i) 0.3605 g of a metal is deposited on the electrode by passing 1.2 amperes of current for 15 minutes through its salt solution. The atomic weight of the metal is 96. What is the valency of the metal?
Write the formula of the following compounds:
(i) Triamminetriaquachromium(III)chloride
(ii) Potassiumhexacyanoferrate(III)
Name the types of isomerism shown by the following pairs of compounds:
(i) [CoCl(H2O)(NH3)4]Cl2 and [CoCl2(NH3)4]Cl.H2O
(ii) [Pt(NH3)4][PtCl6] and [Pt(NH3)4Cl2][PtCl4]
For the complex ion of [Co(NH3)6]3+ :
(i) State the hybridisation of the complex.
(ii) State the magnetic nature of the complex.
Write balanced chemical equations for the following reactions:
(i) Ozone and lead sulphide.
(ii) Chlorine is passed through hot concentrated NaOH solution.
(iii) Sulphuric acid is treated with phosphorous
Give reasons for the following:
(i) Zn+2 salts are white but Cu2+ salts are blue in colour.
(ii) Fluorine gives only one oxide but chlorine gives a series of oxides.
How is potassium dichromate prepared from a sample of chromite ore? Give balanced equations for the chemical reactions involved.
Finely powdered Chromite ore is mixed with soda ash and quick lime. The mixture is then roasted in a reverberatory furnace in presence of excess of air, a yellow mass containing sodium chromate is obtained.
4 FeCr2O4 + 8 Na2CO3 + 7 O2 → 2Fe2O3 + 8 Na2CrO4 + 8CO2
(Sodium chromate)
Conversion of sodium chromate to sodium dichromate.
Sodium chromate is treated with concentrated sulphuric acid to form sodium chromate.
2 Na2CrO4 + H2SO4 → Na2Cr2O7 + Na2SO4 + H2O
Conversion of sodium dichromate to potassium dichromate
Sodium dichromate solution is heated to concentrate. Now add a calculated quantity of potassium chloride is added. On cooling, the least soluble potassium dichromate separate out as crystals.
Na2Cr2O7 + 2 KCl → K2Cr2O7 + 2 NaCl
For the molecule IF7:
(i) Draw the structure of the molecule.
(ii) State the hybridisation of the central atom.
(iii) State the geometry of the molecule