Iron nails are shiny when new but turn brown after being exposed to moist air. This is due to the formation of iron oxide.

Write the short note on:

Corrosion

Write the short note on:

Rancidity

Oil and fat containing food items are flushed with nitrogen. Why? 

When steam is passed through red hot iron, iron oxide and hydrogen is formed. The balanced equation is given below:

$3\mathrm{Fe}+4{\mathrm{H}}_2\mathrm{O}\to {\mathrm{Fe}}_3{\mathrm{O}}_4+4{\mathrm{H}}_2$

What is true for the balanced equation shown above?