1. What is a ppm to mol/L Calculator for Water?

Definition: This calculator converts concentration in parts per million (ppm) to molarity (mol/L) for aqueous solutions.

Purpose: It helps chemists, biologists, and environmental scientists convert between these common concentration units.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( C_{mol} \) — Molarity (mol/L)
• \( ppm \) — Parts per million (dimensionless)
• \( 1000 \) — Density of water (kg/m³)
• \( MW \) — Molecular weight (g/mol)

Explanation: The formula accounts for water density and converts mass-based ppm to molar concentration.

3. Importance of Concentration Conversion

Details: Accurate conversion between ppm and molarity is essential for chemical dosing, solution preparation, and regulatory compliance.

4. Using the Calculator

Tips: Enter the ppm concentration and molecular weight of the solute. Both values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is water density included in the formula?
A: Because ppm is a mass-based unit (mg/kg) while molarity is volume-based (mol/L), we need water density to convert between them.

Q2: Does this work for solutions other than water?
A: No, this calculator assumes the solvent is water (density = 1000 kg/m³). For other solvents, use their specific density.

Q3: What's the difference between ppm and molarity?
A: ppm is mass of solute per million parts of solution, while molarity is moles of solute per liter of solution.

Q4: How precise is this conversion?
A: Very precise for dilute aqueous solutions at standard temperature and pressure (25°C, 1 atm).

Q5: Where can I find molecular weights?
A: Check chemical reference tables, safety data sheets (SDS), or periodic tables for elemental weights.