Final answer:
In chemistry, 'percent' indicates the part of solute per hundred parts of a solution, either by mass or volume. To calculate percentage, one divides the solute quantity by the total solution quantity and multiplies by 100. This standardization aids in comparing and replicating solution concentrations.
Step-by-step explanation:
In chemistry, the term percent refers to the ratio of solute to solution, expressed as parts per hundred. An example of this would be a solution with 5% mass/mass concentration, which means there are 5 grams of solute for every 100 grams of solution. There are two main types of percent concentrations: mass/mass percent (% m/m) and volume/volume percent (% v/v). The % m/m is calculated by dividing the mass of the solute by the mass of the solution and then multiplying by 100. Conversely, the % v/v is calculated by taking the volume of the solute divided by the volume of the solution, again multiplying by 100.
To calculate percent concentrations, you can use a formula or set up equivalent fractions where one fraction has 100 as its denominator. For instance, if 24 students in a class of 100 test positive for an illness, the percent of positive students is 24%. Expressed as an equivalent fraction setup, it is 24/100 = x/100, which directly shows the percentage.
The use of percentages allows for a standardized way to express solution concentrations, making it easier to compare or reproduce solution strengths across different contexts.