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Initial solutionc1
Final solutionc2

Initial solutionV1
Final solutionV2
Added solventΔV

c2/c1 = V1/V2
c1/c2 = V2/V1

Rounding: significant digits.
Decimal sign:

In a dilution the concentration of a solute in a solution is reduced by adding more solvent (often water) to the solution. In the laboratory, frequently the ratios of concentrations (c1/c2 or c2/c1) are given and the solvent is added to the volume V1 of the initial solution to yield the final volume V2. In household and trade often the volume of the initial solution V1 and the volume of the added solvent ΔV are prescribed.

Usage: Always choose the correct unit in the corresponding pull-down-menu before you type a value of a concentration or volume.
At first enter the ratio of the concentrations or of the volumes. This can be done in two ways:
• Either you type a decimal number into one of the corresponding fields directly. After a click on any free space of the window or on the "calculate" button the other ratios are calculated and displayed.
• Or you begin by resetting the calculator with the "reset" button. Then you type the two concentrations or the two volumes (both in the correct unit, respectively) into the corresponding fields. After the input of the second value and a click the ratios are calculated.
When the ratios are displayed, you can type any concentration or volume to calculate the other values.

Example: From a solution with a concentratiion of 0.1 mol/l you want to prepare 500 ml of a solution with a concentration of 2 mmol/l. After you have chosen the correct units, type the two concentrations into the corresponding fields. After a click the ratios are displayed, e.g. V1/V2 = 0.02. Now choose the unit "ml" and type the volume wanted for the final solution "500". After another click you can read the result: You need 10 ml of the initial solution, filled up with solvent to 500 ml to yield a 2 mmol/l solution.

- By the input of a new ratio value all other inputs are resetted.
- Conversions between molar concentrations (mol/l, ...), mass concentrations (g/l, ...) and mixing ratios (%, ...) are not possible.
- All inputs must be positive numbers.
- Effects like a change of the volume that may happen during the mixing process, are not considered.
- Please note the remarks about the representation of numbers..
- There is no warranty for the calculation. Cactus2000 is not responsible for damage of any kind caused by wrong results.
- Please send an email if you have suggestions or if you would like to see more conversions to be included.

© Bernd Krüger, 03.11.2018

Bernd Krüger, 2021