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?

Explain why phenolphthalein is used as an indicator in acid-base titration.

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.

27.

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.

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