Making a solution
- A solution is formed when a solid DISSOLVES in a liquid.
- The solid that has been dissolved is called the solute.
- The liquid used to make the solution is called the solvent.
Example: When salt is dissolved in water then salty water is made
The solute is salt. The solvent is water.
SALT + WATER = SALTY WATER
(SOLUTE) + (SOLVENT) = (SALT
SOLUTION)
Not all solids dissolve by the same amount:
- Salt dissolves easily so is said to be soluble in cold
water.
- Lime (calcium hydroxide) is difficult to dissolve so is slightly soluble
in cold water.
- A substance like sand does not dissolve so is insoluble
in water.
There are many factors (variables) which effect the amount
of solid which dissolves:
- The quantity of solid being used.
- The volume of water
- The rate of stirring
- The size of the particles in the solid
- The temperature of the water.
How to speed up the time taken to dissolve a solid:
- Use warm water
- Stir the solution quicker
- Grind the solid to make the
particles smaller.
How to tell if a liquid is pure or contains a solute:
- Place one or two drops of the filtrate on to a clean watch glass (or
microscope slide)
- Let the water evaporate and see if there is any residue.
- If there is it means that some of the solid did dissolve.
