Question

I have doubt. Why does iron nail in test tube B, not rust? I know the oil layer is there to prevent oxygen from dissolving in the water and the water is boiled or distilled to remove dissolved oxygen but doesn't water already contain oxygen(H2O)? Class 10 Chemistry Activity 3.14 NCERT Pg 53 Read my Bio before answering

Answer 1

Explanation:

Nail A and B does not rust because oil protect nail from rusting by avoiding the contact of oxygen with nail.

Soda lime helps in removing of the rust formed on the nail.

Hence only Nail C rust.

Answer 2

So when the water is distilled , the oxygen which was dissolved in water gets separated and hence there is no oxygen left and as soon as that is done oil layer is made to prevent the atmospheric oxygen to enter the water. So as there is no amount of oxygen , rusting cannot take place. Hence,the iron nail does not rust in test tube B.