What is an insoluble substance?
A substance that will not dissolve in water.
"Insoluble" generally means that a substance does not dissolve in water.
Some examples include: sand, fats, wood, metals, and plastic.
When we put them in water and try to mix them, they will not dissolve.
Insoluble substance is the substance which is not dissolved in a specific dissolving media
An example of insoluble substance is sand (quartz) in water. Thus, sand can be separated from the water by filtration, or/and sedimentation. On the other hand soluble substance can be Silicon Floride, on reacting sand (SiO2) with hydrofloric (HF) acid, according to the following reaction:
SiO2 + HF = Si(F)2 + H2O
According to the above chemical reaction, the product of Silicon Floride "Si(F)2" is soluble in the hydrofloric acid media. On other words, soluble substance form one phase with the dissolving media (chemical), and thus cannot be separated from the liquid solution.
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