Question

Account for the following: (a) Aluminium is more reactive than iron, but its corrosion is less than iron. (b) Hydrogen gas is not evolved when zinc metal reacts with dil. HNO3. (c) Carbon is not used for reducing aluminium from aluminium oxide

Answer 1

At first aluminium react with oxygen from the atmosphere and develops the thin layer of aluminium oxide which provide the resistance from further corrosion
Hydrogen gas is not evolved in the reaction of Zn and HNO3 because nitric acid is strong oxidising agent which oxidised hydrogen produce to water and itself get reduced to any of the nitrogen oxide (N2o NO and NO2)
In third carbon is not used because it is less reactive than aluminium that is not displace Al from its compound the aluminium get separated from its oxide by displacement reaction

Answer 2

Answer:

At first aluminium react with oxygen from the atmosphere and develops the thin layer of aluminium oxide which provide the resistance from further corrosion

Hydrogen gas is not evolved in the reaction of Zn and HNO3 because nitric acid is strong oxidising agent which oxidised hydrogen produce to water and itself get reduced to any of the nitrogen oxide (N2o NO and NO2)

In third carbon is not used because it is less reactive than aluminium that is not displace Al from its compound the aluminium get separated from its oxide by displacement