Question

How did the experiement with the iron filings and sulfur compare with the experiment in which copper sulfate pentahydrate was heated?
Both resulted in gas formation.

Both resulted in color change.

Both involved chemical change.

Both involved physical change.

One involved chemical change while the other involved physical change.

Answer 1

Answer. Statement second and third both are correct.

Explanation: When iron(grey) reacts with sulfur(yellow) chemical change takes place in which iron sulfide is formed which black in color.

                              $Fe(s) + S(s)\rightarrow FeS(s)$

When we heat copper sulfate-pentahydrate(blue) ,water molecule present in its crystal will get evaporated and it will become an anhydrous copper sulfate which will be white in color.

   $CuSO_{4}.5H_{2}O(s)\overset{heat}{\rightarrow} CuSO_{4}(s)+5H_2O(g)$

So, in both the reactions change in color and change in chemical arrangement has taken place.                

Answer 2

The 2nd one and the last one is correct.