Question

Please answer... very urgent!!!

Answer 1

(i) the metals are good conductor of electricity because they are sonorous
(ii) The reason why non-metals do not displace hydrogen from dilute acids is because unlike metals, non-metals do not have a tendency to lose electrons but to gain electrons. ... Only those metals which are reactive than hydrogen will displace H2 from acids.
(iii) It happens because of the displacement reaction copper in CuSo4 solution is displacing iron(Fe) in knife.
(iv) Sodium is kept in kerosene so that that it doesn't react with atmospheric oxygen and evaporate.
(v) Carbon cannot replace the oxides of sodium and aluminum because the affinity of oxygen and they are in the place of higher than carbon in reactivity series. HOPE THIS HELPS YOU

Answer 2

1) Metal atoms have outer electrons which are not tied to any one atom. These electrons can move freely within the structure of a metal when an electric current is applied. There are no such free electrons in covalent or ionic solids, so electrons can't flow through them - they are non-conductors.

2) Non-metals do not replace hydrogen from dilute acids is because unlike metals, non-metals do not have a tendency to lose electrons but to gain electrons. Metals have a tendency to lose electrons. These electrons, which are readily lost by reactive metals like sodium, potassium etc are accepted by hydrogen ions of the acids, reducing them to hydrogen gas (H2).

3) This is because the iron from the knife displaces the copper from the solution (as iron is more reactive than copper )and forms iron sulphate solution which is green in colour.

4) Sodium is a very reactive metal. It is kept in kerosene to prevent it from coming in contact with oxygen and moisture. If this happens, it will react with the moisture present in air and form sodium hydroxide. This is a strongly exothermic reaction, and lot of heat is generated.

5) This is because sodium and aluminium are more reactive than carbon. This means that carbon cannot reduce the oxides of these metals. The two metals are above carbon in the reactivity series and thus have a high affinity to oxygen than carbon does and thus cannot be reduced by it.