Molarity Calculator

Base Molarity Calculator

This base molarity calculator computes the molar concentration of base solutions from their density, purity, and molar mass. Works for NaOH, KOH, Ca(OH)₂, NH₃ (ammonia), and other common laboratory bases.

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Base Molarity Calculator

Density × Purity → Base Molarity

Formula
M = (density × purity% × 1000) / MW
Live Preview
Base Density
Purity (%)
Base Molar Mass
Molarity (M)
How It Works
1
Base Density
Enter value
2
Purity (%)
Enter value
3
Base Molar Mass
Enter value
Molarity (M)

What is Base Molarity?

Base molarity is the molar concentration of a base in solution. Like acids, concentrated bases are sold by density and purity percentage, requiring the same density-purity formula.

Common base molarities: NaOH (50%) ≈ 19.0 M (density 1.52 g/mL, MW 40), KOH (45%) ≈ 11.7 M (density 1.46 g/mL, MW 56.1), NH₃ (28%) ≈ 14.8 M (density 0.90 g/mL, MW 17.03).

Base molarity calculations are used to prepare buffer solutions, neutralize acids in titration experiments, and manufacture cleaning solutions and industrial reagents.

Base Molarity = (density × 1000 × purity%) ÷ molar mass
Visual Concept
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Base Solution
Concentration measured in moles per liter (mol/L)
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Unit: M (Molar)
1 M = 1 mol of solute per 1 liter of solution
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Key Relationship
Molarity = Moles of Solute ÷ Volume of Solution

Base Molarity Formula

The formula for calculating molarity from base molarity:

molarity = moles of solute ÷ volume of solution (L)

To use this formula, you need base mass, volume, and molar mass. The calculator handles all unit conversions automatically.

Enter your values below to see the base molarity formula in action.

mass ÷ volume = concentration = molarity × molar mass

Where mass is in grams (g), volume is in liters (L), and molar mass is in g/mol.

Formula Breakdown
M = n / V
M
Molarity (mol/L)
n
Moles of base (mol)
V
Volume of solution (L)
💡 For polybasic bases, consider equivalents of OH⁻

How to Calculate Base Molarity

Follow these steps to calculate molarity from base molarity:

  1. Identify the base molarity of your solute and gather all known values.
  2. Find the molar mass of the substance from the periodic table or a chemical database.
  3. Enter your base molarity value and select the appropriate unit from the dropdown.
  4. Enter the volume of the solution in liters (L) or select another volume unit.
  5. Click Calculate to get the molarity result instantly.
  6. Verify the result using the step-by-step breakdown provided by the calculator.
Step-by-Step Process
1
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Identify the Base
Determine the base compound and formula
2
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Measure Mass
Weigh the base solute in grams
3
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Find Molar Mass
Look up molar mass from periodic table
4
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Calculate Moles
n = mass ÷ molar mass
5
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Measure Volume
Measure solution volume in liters
6
Compute Molarity
M = moles ÷ volume

Base Molarity Calculator Examples

The examples below show how to use the base molarity calculator in practice.

Example 1: What is the molarity of 10% NaOH? 10% w/v NaOH means 100 g/L. M = 100 / 40 = 2.5 M.

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.

Worked Example Example: NaOH Solution
Mass 40 g
Molar Mass 40 g/mol
Volume 1 L
Molarity 1.00 M

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 base molarity?

M = mass of base (g) ÷ [molar mass (g/mol) × volume (L)]. For example, NaOH molar mass is 40 g/mol.

What is the molarity of 10% NaOH?

10% w/v NaOH means 100 g/L. M = 100 / 40 = 2.5 M.

What bases are commonly used in labs?

NaOH (40 g/mol), KOH (56.1 g/mol), Ca(OH)₂ (74.09 g/mol), and NH₃·H₂O (35.04 g/mol) are the most common.

What units does the Base Molarity Calculator support?

The base 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 Base Molarity Calculator free to use?

Yes. The base molarity calculator is 100% free, requires no sign-up, and works on all devices. All calculations are performed instantly in your browser.