Percent Concentrations:

There are four ways of representing percent concentrations:

%

If both the solute and the solvent are liquids, an easy way to make a solution is by measuring volumes. The concentration of the solute can then be expressed as a percent of the solution by volume. Percent means "parts per hundred". If 20ml of rubbing alcohol is diluted with water to a total volume of 100ml, the final solution is.
20% alcohol by volume. It can be written as 20 percent , OR 20% .




A commonly used relationship for solutions of solid dissolved in liquids is percent . It is usually easy to weigh the solute in grams and to measure the volume of the resulting solution in ml. Percent is the number of grams of solute per 100ml of solution. A solution containing 7g of NaCl in 100ml of solution is 7%





The percentage of solute by mass is the mass of solute present in 100 parts of solution. e.g. 5%
are dissolved in 95 g of water to give 100g of solution.




Five percent means that in 100g solvent 5 solute is present.