How this calculation works
The amount of solute is conserved when a stock solution is diluted with solvent. Concentration units must match. Add solvent to reach the final marked volume instead of assuming liquid volumes always add exactly.
Stock volume = target concentration × final volume ÷ stock concentrationA worked example
To prepare 100 mL of 0.1 mol/L solution from 1 mol/L stock, use 10 mL of stock.
Good to know
Simple dilution with no reaction or solute loss. Does not evaluate chemical compatibility, handling precautions or preparation protocols.
Dilution changes concentration, not the modeled solute amount
Ten millilitres of a 1 mol/L stock contains the same solute amount as 100 mL of a 0.1 mol/L final solution. Adding suitable solvent lowers concentration while preserving solute in the simple model.
This is why the equation multiplies concentration by volume on both sides. The concentration units must match and the volumes must use matching units within that relationship.
Add diluent to the final mark
The reported diluent difference is an ideal volume bookkeeping value. Real liquid volumes need not add exactly when mixed. In a volume-based preparation, the relevant instruction is to reach the required final solution volume using an appropriate procedure.
A final concentration above the stock cannot be reached by adding solute-free diluent alone, so it is rejected. The calculator does not assess chemical compatibility, reactions or safe handling.
A few questions, answered
Can dilution make a solution stronger?
Not under this model. Adding solute-free solvent cannot raise concentration above the stock value.
Does it account for a chemical reaction?
No. It assumes the solute amount is conserved without reaction or loss.