How to Calculate the Percentage of a Solution in Chemistry

Save

Chemists use different types of concentrations for solutions depending on the application. One way to make a solution is by preparing a percent solution. This can give a concentration that relates the amount of one substance against another. Percent solutions can be calculated in respect to either weight or volume. Both the solute and solvent need to be liquids in order to use the volume method. Percent solutions do not tell someone how many moles there are for a given volume.

Things You'll Need

• Calculator
• Analytical scale
• Mixing vessel

Weight Percent Solution

• Measure the mass of the desired solute for the solution using an analytical scale. Follow the manufacturer's instructions to operate your specific scale model properly.

• Obtain the mass of the mixing vessel you are using to mix the solution.

• Mix the solute with the solvent to produce the solution.

• Measure the mass of the entire solution in the mixing vessel in which you already obtained the mass measurement.

• Take the weight of the solution and subtract the weight of the mixing vessel. This should be weight of just the solution itself.

• Divide the mass of the solute from Step 1 by the solution weight found in Step 5. Multiply the result by 100 to obtain the percent solution by weight.

Volume Percent Solution

• Measure the desired amount of solute in a graduated cylinder, noting the lowest part of the meniscus for the measurement.

• Other People Are Reading

• Prepare the solution using standard laboratory safety protocols, noting the final solution volume.

• Divide the volume of solute by the final volume of the solution. Multiply the result by 100 to obtain a percent solution by volume.

Calculating Volume of Solute Needed

• Determine what percentage and what final volume of solution you will need. You may need to anticipate more solution being used for any errors that may occur.

• Divide the percent needed by 100. Multiply the result by the final volume of solution needed. This is the volume of solute that needs to be added to a mixing vessel with graduations.

• Fill the mixing vessel with the solvent to meet the final volume. For example, if 100 mL is the final volume, then place the measure solvent in the vessel then fill the rest of the volume until it reaches the 100 mL line.

Calculating Mass of Solute Needed

• Determine the percent concentration and final volume of solution needed.

• Divide the percentage needed by 100. Multiply the answer by the final volume of solution.

• The result will be the amount of solute, in grams, that needs to be added to the solution for the percent solution.

Tips & Warnings

• Keep all measurements in the same units before performing any calculations.
• Use standard laboratory safety practices before mixing any solutions.

References

• Photo Credit Jupiterimages/Photos.com/Getty Images
Promoted By Zergnet

Related Searches

Check It Out

How to Build and Grow a Salad Garden On Your Balcony

M
Is DIY in your DNA? Become part of our maker community.