Molarity Calculator
Calculate the molarity of a solution. Enter solute mass, solute formula weight (MW), and final volume of the solution.
Solution Formulation
Specify mass, formula weight, and volume.
Calculated Molarity
* Equal to 1000.0 mM (millimolar).
Temperature Dependency
Liquid volume expands with rising temperature, slightly lowering molarity. For high-precision thermal work, use molality.
Common Laboratory Reagent Molecular Weights Reference Table
| Chemical Compound | Chemical Formula | Molecular Weight (g/mol) | Typical Stock Concentration |
|---|---|---|---|
| Sodium Chloride (NaCl) | NaCl | 58.44 g/mol | 5 M (292.2 g/L) |
| Tris Base | C₄H₁₁NO₃ | 121.14 g/mol | 1 M (121.1 g/L) |
| EDTA Disodium Salt | C₁₀H₁₄N₂Na₂O₈·2H₂O | 372.24 g/mol | 0.5 M (186.1 g/L at pH 8.0) |
| Glucose (Dextrose) | C₆H₁₂O₆ | 180.16 g/mol | 1 M (180.2 g/L) |
Methodology & Equations
Molarity Formula
Molarity ($M$) equals total solute moles divided by solution volume in liters.
Preparation Protocol
Weigh solid solute, dissolve in ~80% final volume of solvent, then adjust final volume using a volumetric flask.
Frequently Asked Questions
What is Molarity (M)? ▼
Molarity (M) is the molar concentration of a solution, defined as the number of moles of solute dissolved per liter of solution (mol/L).
How does Molarity differ from Molality? ▼
Molarity measures moles of solute per liter of final solution ($V_{}$) and changes slightly with temperature, whereas Molality measures moles of solute per kilogram of pure solvent ($m_{}$) and is temperature-independent.
How do I prepare a 1 M NaCl solution? ▼
Weigh 58.44 g of pure NaCl (molecular weight = 58.44 g/mol). Dissolve it in approximately 800 mL of deionized water, then bring the total solution volume to exactly 1.0 L in a volumetric flask.
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