Activity to Show Preparation of a Mixture
- Take some Iron filings and Sulphur powder
- Mix and crush them
- Bring a magnet near the mixture
- We see that Iron fillings get attracted to it
This means that it is a mixture as it still shows properties of Iron (to be attracted by a magnet)
Also, the mixture can be separated using physical methods like magnetic separation .
Activity to Show Preparation of a Compound
- Take some iron filings and sulphur powder
- Mix and crush them
- We also heat the same till it is red hot
- Then we let it cool for some time
- Now we bring a magnet near it
The Iron fillings are no longer attracted to magnet
This is because now a compound has been formed which has completely different properties from its constituent elements
Also, any physical method of separation cannot be used to separate the two.
Difference between Mixture and Compounds
Mixture |
Compounds |
They are formed by mixing of 2 or more substances (these may be elements or compounds) |
They are formed by reaction between 2 or more elements |
A mixture has variable composition (Ratio of 2 or more substances may not be same ) |
A compound has fixed composition (Ratio of 2 or more substances is same) |
A mixture shows properties of substances it is made up of (constituent substances) |
Properties of compound are different from its Elements |
Different Elements of Mixture can be separated by Physical methods |
Different Elements of a compound cannot be separated by Physical Methods. A proper chemical or electrochemical reaction is needed |
Example : Salt in water is a mixture. We can add any amount of salt in a glass of water, and call the resultant a mixture. The amount of either of the things doesn't matter. The property of the mixture is the same as that of the constituents salt and water. |
Example : CO 2 is a compound . It is only formed when 1 atom of carbon combines with 2 Atoms of Oxygen. Carbon and Oxygen should always combine in a ratio of 1:2 to form CO 2 . The property of CO 2 is different from that of Carbon and Oxygen . |