Give reason for the following:(a) Sodium is kept immersed in kerosene oil. (b) Iron, the most widely used metal, is never used in its pure state. (c) Hydrogen is not evolved when a metal reacts with nitric acid (except Mn and Mg).

Give reason for the following:(a) Sodium is kept immersed in kerosene

1.	Give reason for the following:(a) Sodium is kept immersed in kerosene oil. (b) Iron, the most widely used metal, is never used in its pure state. (c) Hydrogen is not evolved when a metal reacts with nitric acid (except Mn and Mg).
Answer» Solution : (a) Sodium is a reactive metal. It reacts both with air and water. `NA + 2H_2Oto NAOH + H_2` Kerosene does not react with sodium. (b) Iron is a soft metal. It is alloyed with other elements for different uses. (c) This is because hydrogen gas FIRST evolved reacts with `HNO_3`to FORM OXIDES of nitrogen.