Question

1) If you leave a piece of iron in the open for a few days, it acquires a film of brownish substance,
called rust.
a) Do you think rust is different from iron?
b) Can you change rust back into iron by some simple method?
c) Do you think formation of rust from iron is a chemical change?​

Answer 1

Answer:

a)Yes, rust is chemically different from iron. b)No.

c)Yes, it is a chemical change

Answer 2

Required Jawab :

1 ] Pehela waala answer :

• Yes, The rust is different from iron as iron is a metal and quite lustrous where as the rust from due to the action of exterior factors which are water and air is a reddish - brown layer which us not lustrous

2 ] dusra waala answer

• We can can't change the rust back into iron but we can remove the layer of rust from the iron using galvanizator amd electrolysis

Note : Yeh second waala question confusing hai ^^ Once a metal rusted is rusted.!!that can't be turned back as chemical changes are irreversible but you can remove the rust..!! but here comes the problem if the questioner ment by the term "rust back into iron" then the answer is no , or if he / she ment by getting the same luster back then the answer is yes ^^

3] Third waala answer:

• Yes, it is a chemical change as we know that a change is stated as a chemical reaction when a substance acts up on another substance forming a new substance

Here,

• Iron ( Fe ) + Water ( H2O) + oxygen ( O2 ) = Rust

Sorry mai rust ka chemical formula bhul gayi xD I think it is Fe2O3• x H2O

Hope this helps ^_^