How to Calculate Concentration Using Salt
If you want to get better at chemistry, calculations are one thing you can’t avoid, it’s always going to pop like an unwanted pimple.
and the best way to deal with it is to master it, and when I say master it I mean truly master it
You’ve got to get good to the point of relating chemistry to real-life situations because the more familiar you are with something the easier it is.
One of those unwanted pimples is how to calculate concentration in chemistry, simple but yet so complex
But we’re going to master it so it doesn’t get the better of us
Related: How to set up a lab at home
What is concentration?
In chemistry, the word “concentration” relates to the components of a mixture or solution, chemistry refers to the amount of a substance in a defined space.
And they’re a lot of ways which we could calculate it, some are:
- Molarity (M) – moles of solute/liters of solution (not solvent!)
- Mass Concentration (kg/m3 or g/L) – mass of solute/volume of solution
- Normality (N) – grams active solute/liters of solution
- Molality (m) – moles of solute/mass of solvent (not mass of solution!)
- Mass percent (%) – mass solute/mass solution x 100% (mass units are the same unit for both solute and solution)
- Volume Concentration (no unit) – volume of solute/volume of mixture (same units of volume for each)
- Number Concentration (1/m3) – number of entities (atoms, molecules, etc.) of a component divided by the total volume of the mixture
- Volume Percent (v/v%) – volume solute/volume solution x 100% (solute and solution volumes are in the same units
But I can’t take all of them into one article so well just be dealing with one
Mass Concentration (kg/m3 or g/L) – mass of solute/volume of solution
Mass concentration refers to the moles of solute divided by the mass/volume of the solution
and we’ll be dealing with just this one because it’s really easy making it a good way to learn how to calculate concentration fast.
How to calculate concentration using salt
To do this you’ll need
- A Weighing balance
- A glass of water
- A Spoon
Time to apply chemistry to a real situation
- Take a glass and measure out about 500 mL of water
- Use your spoon to take a little chunk of salt, place it on the weighing balance, and record the weight of the salt on the weighing balance ( be careful not to take too much salt the process needs to be done slowly to avoid errors )
- And the salt on your weighing balance to your glass of water
- Repeat this process until the water can’t dissolve any more salt and stop.
- Add up all the weights of salt from your reading,( it’s time to calculate )
Remember we said we’ll be dealing with Mass concentration and the formula for mass concentration is mass of solute/volume of solution or simply C=m/V
Where C= concentration, m= mass of solute, v= volume of solution
Related: How to memorize the periodic table
So all you need to do now is divide the amount of salt dissolved by the volume of water.
Example: If the amount of salt dissolved was 5 grams, we would divide 5 grams by the volume of water ( 500 mL)
convert 500 mL to liters
5 grams / 0.50 L = 10 g/L
Meaning the concentration of salt in the water was 10 g/L
Difference Between Concentration and Dilution
Two related terms are concentrated and dilute. Concentrated refers to chemical solutions that have high concentrations of a large amount of solute in the solution.
If a solution is concentrated to the point where no more solute will dissolve in the solvent, it is said to be saturated. Dilute solutions contain a small amount of solute compared with the amount of solvent.
In order to concentrate a solution, either more solute particles must be added or some solvent must be removed. If the solvent is nonvolatile, a solution may be concentrated by evaporating or boiling off the solvent.