Long Answer Type
Short Answer TypeWhat difficulties arise in the extraction of lithium?
The lithium metals can not be extracted by the usual procedure due to the following reasons:
(i) The metal can not be obtained by the reduction of its oxide (Li2O or Na2O) because it is a strong reducing agent by itself and the common reducing agents such as carbon, hydrogen, magnesium and aluminium cannot be used.
(ii) Metal can not be obtained by the electrolysis of the aqueous solution of its salt like LiCl because the metal formed at the cathode will violently react with water to form lithium hydroxide and hydrogen.
(iii) Even molten LiCl can not be used for the electrolysis because the melting point of the salt is so high that it is quite difficult to attain and maintain this temperature.
(iv) Chlorine, a by-product of electrolysis, will corrode the material of the vessel at this higher temperature.
Long Answer TypeWhat happens when:
(i) Lithium reacts with air
(ii) Lithium reacts with water
(iii) Lithium reacts with halogen
(iv) Lithium reacts with acids?
Short Answer TypeAccount for the following:
(i) Lithium can not form monovalent cation (Li+) easily.
(ii) Lithium iodide is more covalent than lithium fluoride.
Long Answer TypeWhat difficulities arise in the extraction of sodium? How these difficulties are overcome?
Short Answer TypeWhat happens when:
(i) sodium reacts with hydrogen halide,
(ii) sodium reacts with acetylene,
(iii) sodium is heated with hydrogen and
(iv) sodium is treated with mercury ?
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