Stock Solution Molarity Calculator
This stock solution molarity calculator determines the molar concentration of a concentrated stock solution prepared by dissolving a known mass of solute in a specific volume. Stock solutions are typically 10–1000× more concentrated than working solutions.
Stock Solution Molarity Calculator
Mass → Moles → Molarity
M = mass / (MW × V) What is Stock Solution Molarity?
Stock solution molarity is the concentration of a concentrated master solution from which working solutions are prepared by dilution. Knowing the exact stock molarity is essential for accurate downstream dilutions.
To prepare a stock solution, you weigh a precise amount of solute and dissolve it in a measured volume of solvent. The molarity formula is the same: M = mass ÷ (MW × volume).
Common stock concentrations: 1 M, 10 mM, 100 mM. Higher concentrations minimize dilution effects and preserve solvent in downstream reactions.
Stock Solution Molarity Formula
The formula for calculating molarity from stock solution concentration:
To use this formula, you need mass, molar mass, and volume of stock. The calculator handles all unit conversions automatically.
Enter your values below to see the stock solution molarity formula in action.
Where mass is in grams (g), volume is in liters (L), and molar mass is in g/mol.
How to Calculate Stock Solution Molarity
Follow these steps to calculate molarity from stock solution concentration:
- Identify the stock solution concentration of your solute and gather all known values.
- Find the molar mass of the substance from the periodic table or a chemical database.
- Enter your stock solution concentration value and select the appropriate unit from the dropdown.
- Enter the volume of the solution in liters (L) or select another volume unit.
- Click Calculate to get the molarity result instantly.
- Verify the result using the step-by-step breakdown provided by the calculator.
Stock Solution Molarity Calculator Examples
The examples below show how to use the stock solution molarity calculator in practice.
Example 1: How do I prepare a 10 mM stock from powder? For a 10 mM stock in 10 mL: mass = M × MW × V = 0.01 × MW × 0.01 = MW × 10⁻⁴ g.
Example 2: Using the formula: molarity = moles ÷ volume, compute the result and verify with the calculator above.
Example 3: Enter your own values into the calculator to see personalized step-by-step results.
Molarity Calculator Tools
Explore our collection of 20 specialized molarity calculators. Each tool is designed for a specific type of calculation with its own unique input fields and formulas.
FAQs
How do you calculate stock solution molarity?
Weigh the solute, dissolve in a known volume: M = mass (g) / [MW (g/mol) × volume (L)]. Stock solutions are typically 10–100× the working concentration.
How do I prepare a 10 mM stock from powder?
For a 10 mM stock in 10 mL: mass = M × MW × V = 0.01 × MW × 0.01 = MW × 10⁻⁴ g.
How long can stock solutions be stored?
Stability depends on the compound. Aqueous stocks are typically stable for weeks at 4°C or months at −20°C. Check compound-specific guidelines.
What units does the Stock Solution Molarity Calculator support?
The stock solution molarity calculator supports mass units (g, mg, µg, kg), volume units (L, mL, µL, gal), molar mass (g/mol, kg/mol), and molarity units (M, mM, µM, nM, pM, fM, aM).
Is the Stock Solution Molarity Calculator free to use?
Yes. The stock solution molarity calculator is 100% free, requires no sign-up, and works on all devices. All calculations are performed instantly in your browser.