The following questions are relevant to the extraction of Aluminium.
i) State the reason for the addition of caustic alkali to bauxite or during purification of bauxite.
(ii) give a balanced chemical equation for the above reaction.
(iii) Along with cryolite and alumina, another substance is added to the electrolyte mixture. Name the substance and give one reason for the addition.
i) Caustic alkali is added to bauxite, to dissolve bauxite ore and obtain a solution of sodium aluminate.
ii) Al2O3.2H2O +2NaOH +heat ---> 2NaAlO2 +3H2O
iii) CaF2 adds along with cryolite and alumina. To reduce the high melting point of alumina and to make it a conducting medium .
Draw an electron dot diagram to show the structure of hydronium ion. State the type of bonding present in it.
State one observation for each of the following;
Zinc nitrate crystals are strongly heated
State one chemical test between each of the following pairs:
Ferrous nitrate and lead nitrate.
Give balanced equation for the following reaction:
Dilute nitric acids and copper carbonate.
Give reason for the following:
An aqueous solution of sodium chloride conducts electricity.
State one observation for each of the following:
Sodium hydroxide solution is added to ferric chloride solution at first a little and then in excess.
State one observation for each of the following:
Excess ammonium hydroxide solution is added to lead nitrate solution.
State one observation for each of the following;
A zinc granule is added to copper sulphate solution.