Dilution and Molarity Lab: Change Mass and Volume
Calculate concentration with an ideal dilution model. Change solute mass and solution volume, compare presets, and solve preparation challenges.
Free, with no sign-up.
For High school students and adults reviewing the topic.
About 8 minutes.
How does it work?
- Choose a solute and the mass used to prepare the initial solution.
- Set the initial solution volume and a final volume at least as large. Volumes refer to solution, not water added.
- Compare concentrations, then check a challenge.
What will you get?
Track conserved solute and prepare target concentrations in an ideal model.
What does the model assume?
- This is ideal dilution only. All of the measured solute is treated as dissolved, with no reaction, evaporation, or precipitation.
- The model does not predict solubility limits or whether a real mixture can dissolve the chosen mass.
- Molarity counts moles of the named compound per liter of solution, not the total moles of ions after dissociation.
- Volumes are measured final solution volumes. The model does not assume separate solute and solvent volumes add exactly.
- The rounded molar masses are 58.44 g/mol for sodium chloride and 74.55 g/mol for potassium chloride, using NIST reference data.
Which setup would you like to try?
What can you change?
Range: 0 to 10 g.
Range: 25 to 1000 mL.
Range: 25 to 2000 mL.
What does the model predict?
| Quantity | Value | Unit |
|---|---|---|
| Moles before and after dilution | 0.025 | mol |
| Initial molarity | 0.25 | mol/L |
| Final molarity | 0.1 | mol/L |
Can you reach these targets?
Prepare 250 mL of 0.100 mol/L NaCl from a 100 mL initial solution.
- Target: Initial solution volume = 100 mL; tolerance 0 mL.
- Target: Final solution volume = 250 mL; tolerance 0 mL.
- Target: Final molarity = 0.1 mol/L; tolerance 0.0001 mol/L.
Required solute: Sodium chloride (NaCl)
Use 2.922 g NaCl in 100 mL of initial solution. Dilute it to 0.125 mol/L.
- Target: Solute mass = 2.922 g; tolerance 0 g.
- Target: Initial solution volume = 100 mL; tolerance 0 mL.
- Target: Final molarity = 0.125 mol/L; tolerance 0.0001 mol/L.
Required solute: Sodium chloride (NaCl)