Answer:
The value of x will be " 3 ".
Step-by-step explanation:
The iron reacts with moist air and leads to formation of reddish brown layer on its surface that is rust .
It is corrosion but in case of iron is called as "rust ".
The conditions necessary for rusting is :
When iron comes in contact with moist air rusting occurs .
The chemical formula of rust is ; Fe₂O₃.x H₂O
The overall reaction can be represented as :
4 Fe + xO₂-->2 Fe₂O₃
we also know that , mass in any chemical reaction cant be created nor be destroyed ,it remains conserved .So,in accordance with Law of conservation of mass we balance the equation .
Therefore , to balance oxygen we need to multiply it with 3 so as to equalize 6 moles on both sides .