Molarity Dilution Calculator:
Enter the values of initial molarity, M1(mol/L), initial volume, V1(L) and final volume, V2(L) to determine the value of Final molarity, M2(mol/L).
Molarity Dilution Formula:
Molarity dilution is the process of reducing the concentration of a solution by adding more solvent without changing the amount of solute present. This is a fundamental concept in chemistry, commonly used in laboratory experiments, pharmaceuticals, and industrial applications.
The molarity (M) of a solution represents the number of moles of solute per liter of solution and is given in units of moles per liter (mol/L). When a solution is diluted, the total number of moles of solute remains constant before and after dilution, but the volume increases, leading to a decrease in concentration.
The dilution formula is derived from the conservation of moles principle, which states that the initial moles of solute (before dilution) equal the final moles of solute (after dilution). The dilution formula relates the initial molarity (M1(mol/L)), initial volume (V1(L)), final molarity (M2(mol/L)), and final volume (V2(L)) of a solution.
This relationship is useful in preparing solutions of desired concentrations from more concentrated stock solutions, ensuring precise measurements in chemical reactions. By rearranging the equation, any of the variables can be determined if the other three are known.
The formula is particularly useful in analytical chemistry, where precise concentrations are required for titrations, buffer preparations, and reagent standardizations. Since molarity depends on volume, changes in temperature can slightly affect concentration due to volume expansion or contraction of the solvent.
Dilutions should be carried out carefully using volumetric glassware, such as pipettes and volumetric flasks, to maintain accuracy. The dilution equation assumes ideal mixing conditions and no significant solute interaction with the solvent beyond simple dilution.
Understanding molarity dilution is crucial for maintaining consistent reagent strengths in biochemical and medical applications. It also plays a key role in environmental science, where the dilution of pollutants in water bodies is analyzed to assess contamination levels.
Final molarity, M2(mol/L) in moles per litre is equal to the product of initial molarity, M1(mol/L) in moles per litre and initial volume, V1(L) in litres, divided by final volume, V2(L) in litres.
Final molarity, M2(mol/L) = M1(mol/L) * V1(L) / V2(L)
M2(mol/L) = final molarity in mole per litres, mol/L.
M1(mol/L) = initial molarity in mole per litres, mol/L.
V1(L) = initial volume in litres, L.
V2(L) = final volume in litres, L.
Molarity Dilution Calculation:
- A scientist prepares a diluted solution by taking 0.050 L of a 1.5 M NaCl solution and adding water until the total volume becomes 0.200L. What is the final molarity?
Given: M1(mol/L) = 1.5mol/L, V1(L) = 0.050L, V2(L) = 0.200L.
Final molarity, M2(mol/L) = M1(mol/L) * V1(L) / V2(L)
M2(mol/L) = 1.5 * 0.050 / 0.200
M2(mol/L) = 0.375mol/L.
- How much of a 2.0 M HCl stock solution is needed to prepare 0.500L of a 0.5 M solution?
Given: M1(mol/L) = 2.0mol/L, V2(L) = 0.500L, M2(mol/L) = 0.5mol/L.
Final molarity, M2(mol/L) = M1(mol/L) * V1(L) / V2(L)
V1(L) = M2(mol/L) * V2(L) / M1(mol/L)
V1(L) = 0.5 * 0.500 / 2.0
V1(L) = 0.250 / 2.0
V1(L) = 0.125L.