Answer the the following question:
 
1.  Nisha is provided with three iron nails, each dipped in oil, water and vinegar. Which iron nail will not rust, and why?
 
i.  Name the methods to prevent rusting.
 
ii. What is the nature of vinegar? Why does the iron nail placed in vinegar rust faster than iron nail placed in water?
Reason:
 
iii. Write the word equation for rusting.