What is the shape of an acetylene molecule ? Mention the type of hybridization present in it. 

Correct the following statements :

For water-system, the number of phases that can exist in equilibrium is two.

Complete the following statements by selecting the correct alternative from the choices given :

Mac Arthur-Forrest process is used for the extraction of:

Fill in the blanks choosing appropriate words given in brackets : 

[Olefenic, aldol, safety matches, sodium sulphite, homolytic, organometallic, aldol condensation, flowers of sulphur, pesticides, heterolytic, antiknock, β-hydroxy-aldehyde, rat poison, sulphur dioxide, free radicals, antichlor, mixed condensation, photography, sodium hydroxide, charged species].

(i) Red phosphorus is used in the manufacture of______and________.

(ii) Hypo is prepared by boiling________solution with_________in alkaline medium.

(iii) The breaking of covalent bonds may be either through_______or by________fission.

(iv) Acetaldehyde in presence of dilute alkali gives_______and the reaction is called______.

(v) TEL, an_______compound, is used as an________agent.

(i) Write the equation which relates the number of phases, components and degree of freedom of a system in equilibrium.    

(ii) How many phases and components are there in a system consisting of:

(1) a mixture of O₂ and N₂ gases

(2) N₂ gas containing H₂O vapour

(3) a mixture of ice and water

(4) a mixture of powdered iron and sulphur

(5) a lump of solid iron (II) sulphide

Give a suitable explanation, in brief, for your answer.

For the extraction of aluminium, write  

(i) The most important ore.

(ii) One method for the purification of the mentioned ore.

(iii) The role of cryolite and calcium fluoride in electrolysis.