How to Calculate the Concentration of a Solution
Learn the vocabulary., Learn how concentration is written.
Step-by-Step Guide
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Step 1: Learn the vocabulary.
Concentration is a ratio comparing the amount of one substance to the amount of the entire mixture.
For instance, if you plan to mix sugar and vinegar together for an experiment, you'll need to calculate the concentration of sugar in the mixture.
Here's how each ingredient would be described in the chemistry report:
The sugar is the solute, which is the substance being dissolved.
You are measuring the concentration of the solute.
The vinegar is the solvent, which is the substance you are dissolving something in.
After you mix them together, you end up with a solution.
To calculate the concentration, you'll need to the total amount of the solution, which you can get by adding the solute and solvent quantities together.
If you forget which is the solute and which the solvent, remember this example.
Sugar and solute both contain the letter U, while vinegar and solvent both contain the letter V. -
Step 2: Learn how concentration is written.
Since there are different ways for expressing the "amount" of a given substance, there's more than one way to write a concentration.
Here are the most common ways:
Grams per liter (g/L.) Simply the mass of a solute in grams dissolved in a given volume of solution.
Usually used for solutions made from solid solutes and liquid solvents, like our sugar and vinegar example.
Molarity (M.) The number of moles of a solute divided by the volume of the solution.
A mole is a unit often used in chemistry to describe the number of atoms or molecules of a substance.
Parts per million (ppm.) The number of units (usually grams or milligrams) of a solute found in one million units of the solution.
Usually used for very dilute water solutions.
Percent composition.
The number of parts (again, usually grams) of solute found in one hundred parts of solution.
The percent symbol % means "out of 100" so you can easily write the fraction as a percentage.
Detailed Guide
Concentration is a ratio comparing the amount of one substance to the amount of the entire mixture.
For instance, if you plan to mix sugar and vinegar together for an experiment, you'll need to calculate the concentration of sugar in the mixture.
Here's how each ingredient would be described in the chemistry report:
The sugar is the solute, which is the substance being dissolved.
You are measuring the concentration of the solute.
The vinegar is the solvent, which is the substance you are dissolving something in.
After you mix them together, you end up with a solution.
To calculate the concentration, you'll need to the total amount of the solution, which you can get by adding the solute and solvent quantities together.
If you forget which is the solute and which the solvent, remember this example.
Sugar and solute both contain the letter U, while vinegar and solvent both contain the letter V.
Since there are different ways for expressing the "amount" of a given substance, there's more than one way to write a concentration.
Here are the most common ways:
Grams per liter (g/L.) Simply the mass of a solute in grams dissolved in a given volume of solution.
Usually used for solutions made from solid solutes and liquid solvents, like our sugar and vinegar example.
Molarity (M.) The number of moles of a solute divided by the volume of the solution.
A mole is a unit often used in chemistry to describe the number of atoms or molecules of a substance.
Parts per million (ppm.) The number of units (usually grams or milligrams) of a solute found in one million units of the solution.
Usually used for very dilute water solutions.
Percent composition.
The number of parts (again, usually grams) of solute found in one hundred parts of solution.
The percent symbol % means "out of 100" so you can easily write the fraction as a percentage.
About the Author
Beverly Coleman
Creates helpful guides on cooking to inspire and educate readers.
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