Chemistry
Learning physics
and chemistry
easily and freely - Science for elementary school, middle school and
high school
Free online chemistry lesson for elementary school, middle school and high school.
Mixtures and solutions
Conservation of mass on dissolving
When salt is dissolved in water, the salt crystals do not cease to exist: they are only broken up into particles so small they are not visible to the naked eye.
Disappearance of salt during a dissoulution is therefore only apparent: actually there is always the same amount of salt.
Since salt doesn't really disappear, it keeps the mass he had before dissolution.
For iinstance if 10 g of salt idissolved 10 in 200 g of water then the resulting mixture have a mass equal to 200 + 10 or 210 g.
This reasoning can be extended to all dissolutions.
There is always conservation of mass when a solid is dissolved in a liquid: The total mass of solvent and solute is equal to the mass of solution obtained.
©2021 Physics and chemistry