Question

During an activity, a student added 10g iron filings and 10g sulphur powder in a bowl. He broughtamagnet over the bowl and

noticed thatiron filings were pickedup by the magnet. He put sulphur and ironfilings back into the bowl and put it on heat. After some

time, he brought the magnet over it again; this timethe iron filings were not attracted to the magnet.What can be inferred from the activity?


a) The contentsin the bowl before heating can be classified as a mixture because they appear different.


b) The contentsin the bowl before heating can be classified as a mixture because they could be separated.


c) The contents in the bowl after heating can be classified as a mixture because they were not affected by the magnet.


d) The contents in the bowl after heating can be classified as a mixture because their properties changed after heating.
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Answer 1

The contents in the bowl before heating can be classified as a mixture because they could be separated.

Option (b) is correct.

Explanation:

• When iron filings and sulfur are mixed together, it forms a heterogenous mixture which can be separated.
• Iron and sulfur have no reacted together to form a bond before heating, therefore it is a mixture.
• But after heating both iron and sulfur react with each other and form a ferrous sulfide compound.
• Thus, this is a black color compound after heating, not a mixture.
• The reaction is  
• Fe + s ----> FeS

Answer 2

Answer:

option b is correct