How can you justify that air is a homogenous mixture. And identify substance present in it.
Answers
Air is a mixture of nitrogen, oxygen, carbon dioxide, argon, water vapour,hydrogen etc in their gaseous forms.
Now can you see nitrogen present in air separate from oxygen?
Can you see oxygen separate from carbon dioxide in air?
Even if you see around you, do you find any difference in air present right to you with air present left you?
Can you distinguish their components by looking at it?
The answer to all these questions is a big NO.
Pure air made of some definite gases is a homogeneous mixture as all its components are mixed together very well and do not have visible boundaries.
Note: The fact goes for pure air only. Air mixed with pollutants is not a homogeneous mixture. Its heterogeneous.
We often take air as a single unit. In reality, air is composed of several gases. The composition of air consists of three key components of air, namely Nitrogen (78%), Oxygen (21%), Argon (1%), Carbon-di-oxide (0.03%) and water vapor. Air also has some other gases but they are in very minute percentage.
Hope you got this.
Air has uniform composition throughout therefore it has a homogeneous mixture. It is composed of 78% nitrogen, 21% oxygen, 0.9% argon and 0.03% carbon dioxode with some moisture.