PPM to Molarity Calculator

The PPM to Molarity Calculator converts between parts per million (ppm) and molarity for dilute aqueous solutions. Ppm expresses concentration as milligrams of solute per liter of solution, while molarity counts moles per liter.

For dilute water-based solutions at room temperature, 1 ppm is approximately 1 mg/L. The conversion formula is:

$$\mathrm{ppm} = M \times MM \times 1000$$

where $M$ is molarity in mol/L and $MM$ is molar mass in g/mol. Rearranging gives:

$$M = \frac{\mathrm{ppm}}{MM \times 1000}$$

For example, seawater with about 0.599 M NaCl ($MM = 58.44$ g/mol) corresponds to roughly 35,000 ppm. A 200 ppm NaOH solution converts to about 0.005 M.

Frequently Asked Questions

What is ppm in chemistry?

Parts per million (ppm) indicates how many parts of solute exist per million parts of solution. For dilute aqueous solutions, ppm is commonly expressed as mg/L.

How do I convert ppm to molarity?

Divide ppm by the product of molar mass and 1000. The formula is M = ppm / (molar mass × 1000), with molar mass in g/mol.

Why is molar mass required?

Ppm is a mass-based concentration while molarity is mole-based. Molar mass bridges the two by converting grams to moles.

Does this work for non-aqueous solvents?

This calculator assumes dilute aqueous solutions where ppm ≈ mg/L. For other solvents, density corrections may be needed.

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PPM to Molarity Calculator

PPM to Molarity Calculator

Frequently Asked Questions

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