Final answer:
The percent remaining in the flask can typically be calculated by dividing the remaining amount of solute (by volume or mass) by the initial amount and then multiplying by 100%.
Step-by-step explanation:
In chemistry, to calculate the percent remaining in a flask, you would typically divide the volume or mass of the remaining solute by the original volume or mass of the solute before the reaction or process began, and then multiply by 100%. This could apply to processes like reactions, dilutions, or evaporations, depending on the context. Two common ways to express concentration are percent by volume and percent composition.
For instance, if we want to calculate the percent by volume and you have a solution made by adding 40 mL of ethanol to 20 mL of water, you would divide the volume of the ethanol (40 mL) by the total volume of the solution (40 mL + 20 mL), and then multiply by 100%.
Similarly, the percent yield is determined by dividing the actual yield by the theoretical yield and multiplying by 100%. Whereas, for determining the percent composition, you would divide the mass of each element by the overall mass of the compound and then convert it to a percentage.