Molarity Calculator

Molarity is evaluated from Moles of Solute, Volume of Solution and Molarity. The calculation reports Molarity, Moles of Solute and Volume of Solution.

Results

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About the Molarity Calculator

Molarity is treated here as a quantitative relation between Moles of Solute, Volume of Solution, Molarity and Molar Mass and Molarity, Moles of Solute, Volume of Solution and Volume of Solution.

The calculator uses a multi formula configuration. Each reported value is read as a direct evaluation of the stored rules with the declared field formats and units.

Formula basis:
M = n / V - Molarity (mol/L)
n = M x V - Moles from molarity and volume
V = n / M - Volume from moles and molarity
From mass: n = mass (g) / molar_mass (g/mol)
Then: M = mass / (molar_mass x V)

Interpret the outputs in the order shown by the result fields. Optional inputs affect only the outputs that depend on those variables.

Formula & How It Works

The calculation applies the following relations exactly as recorded in the metadata:

M = n / V - Molarity (mol/L)
n = M x V - Moles from molarity and volume
V = n / M - Volume from moles and molarity
From mass: n = mass (g) / molar_mass (g/mol)
Then: M = mass / (molar_mass x V)

Each output field is produced by substituting the supplied inputs into the relevant relation and then applying the declared rounding or text format.

Worked Examples

Example 1: Prepare 0.5 M NaCl Solution

Inputs

volume: 0.5 molarity: 0.5 molar_mass_input: 58.44
Moles of Solute: 0.25 mol

With Volume of Solution = 0.5, Molarity = 0.5 and Molar Mass = 58.44 as the stated inputs, the result is Moles of Solute = 0.25 mol. Each value corresponds to the declared output fields.

Example 2: Normal Saline (IV Fluid) Concentration

Inputs

volume: 1 molar_mass_input: 58.44 mass_g: 9
Molarity: 0.154 mol/L. Moles of Solute: 0.154 mol

With Volume of Solution = 1, Molar Mass = 58.44 and Mass of Solute = 9 as the stated inputs, the result is Molarity = 0.154 mol/L and Moles of Solute = 0.154 mol. Each value corresponds to the declared output fields.

Example 3: Acid Solution — Chemistry Lab

Inputs

moles: 0.1 volume: 0.025
Molarity: 4 mol/L

With Moles of Solute = 0.1 and Volume of Solution = 0.025 as the stated inputs, the result is Molarity = 4 mol/L. Each value corresponds to the declared output fields.

Example 4: Blood Glucose — US to International Units

Inputs

volume: 0.1 molar_mass_input: 180.16 mass_g: 0.1
Molarity: 0.0056 mol/L. Moles of Solute: 0.0006 mol

With Volume of Solution = 0.1, Molar Mass = 180.16 and Mass of Solute = 0.1 as the stated inputs, the result is Molarity = 0.0056 mol/L and Moles of Solute = 0.0006 mol. Each value corresponds to the declared output fields.

Common Use Cases

  • Find molarity of a solution prepared in the lab
  • Calculate moles of solute in a given volume
  • Determine volume needed for a specific number of moles