Aluminium is reduced using electricity for its preparation. But gold which is seen in free form can be separated easily why?

The symbols of some metals are given below. Pb, Fe, Sn, Na, Au a) Which metal is produced by using electricity as reducing agent? b) Which metal exist in the free state? c) Which compounds of these metals are more stable?

Colloidal solution of gold is prepared by striking an electric are between gold electrodes kept in water. What is this method called as? Why is it regarded as a dispersion method?

Write the reasons of followings: a) Aluminium is a very good reducing agent. b) Copper is a better conductor of electricity. But aluminium is widely used for making electric wires. c) Alumina is dissolved in molten cryolite at the time of electrolysis.

Aluminium is prepared industrially by Hall- Heroult process. Various steps in the concentration of ore are given below. Write them in the correct order. i)The precipitate formed is separated, washed and strongly heated to get alumina. ii) Crushed bauxite is leached with hot sodium hydroxide solution. iii) Impurities are removed from the sodium aluminate solution by filtration. iv) Solution is diluted after adding a little aluminium hydroxide, to precipitate aluminium hydroxide .

The names of some metals are given below. Tungsten, Gold, Sodium, Copper, Iron, Magnesium Answer the following questions by selecting the appropriate ones from the list. Which metal with high malleability is used for making ornaments? Which of these metals reacts with cold water? Which of these is a hard metal but corrodes easily?

Aryl diazonium salts are very good synthetic reagents that can be used for the preparation of a wide variety of organic compounds Why are aryl diazonium ions more stable than alkyl diazonium ions ?

The order of reactivity of some metais are given. Answer the following questions by analysing it. Al gt Zn gt Cu gt Au a) Which metal is produced by the electrolysis of its molen salt? b) Matal occur in free state in nature. c) Metal produced by the self oxidation-reduction reaction. d) Metal are which is reduced by carbon.