Volume
- Volume is the measure of how much space a substance takes up.
- It is usually designated as liters, deciliters or milliliters.
- It is useful to remember that one cubic meter is 1000 liters, or that one one cubic centimeter is 1 milliliter.
- Also remember that water's density is roughly 1g/ml, or 1kg/l.
- Volume percentage can be used to find how much of a mixture a certain substance makes up.
- Volume is written as V, whereas volume percentage is written as V%.
Examples
- In the dilution instructions of a juice concentrate, the recommended ratio to water and juice is 1:4.
This means that the prepared juice contains 4 parts water, and 1 part juice.
This means that 1/5th of the solution is juice, or 20%, and 4/5ths of the solution are water, or 80%.
Formula: V% = V(volume of solute)/V(volume of solution) x 100%
Example: V% = 1/5 x 100% = 20% - On the side of the juice concentrate package, it writes that 100 grams of juice concentrate contains 7.4 grams of sugar.
- Then if the concentrate is diluted in a 1:4 ratio with 4 deciliters of water, the amount of sugar in the diluted concentrate can be calculated via the following:
Formula: m% = m(component)/m(solution) x 100%
Example: m%(sugar) = m(sugar)/m(juice drink) x 100% = 7.4g/500g x 100% ≈ 1.5% - Remember that m% stands for mass percentage.
- The calculation for m% is the same for V% other than it uses units of mass instead of units of volume.
Per Mille and Parts Per Million
- Similarly to percentage, sometimes permille and parts per million can be used.
Permille
- Per Mille is similar to percentage, however it is parts per 1000 instead of parts per 100.
- It uses the symbol ‰
- It can be shown as: x/1000.
Parts Per Million
- Likewise, ppm stands for parts per million, and is similar to permille, however it is over 1 million instead of 1000.
- It uses the symbol ppm.
- It can be shown as x/1000000.
Concentration
- Concentration is based on the amount of solute.
- Concentration indicates the amount of substance in a 1 liter solution.
- Concentration can also indicate the amount of substance in a 1 deciliter solution however, and usually the more convenient unit is used.
- A higher concentration would indicate more of the substance in the solution, and vice versa.
- It's letter symbol is c.
- It's main units are moles per liter and moles per deciliter.
- Written as mol/l and mol/dl respectively.
- The equation used to calculate concentration is c = n/V.
- n is the amount of substance and V is the volume of the solution.