1. What is Molarity?

Molarity (M) is a unit of concentration representing the number of moles of a solute per liter of solution. It's one of the most commonly used units in chemistry for quantifying solution concentrations.

2. How Does the Calculator Work?

The calculator uses the molarity formula:

Where:

• \( M \) — Molarity (mol/L)
• \( C \) — Concentration in milligrams per liter (mg/L)
• \( MW \) — Molecular weight in grams per mole (g/mol)

Explanation: The formula converts mass concentration (mg/L) to molar concentration (mol/L) by dividing by the molecular weight and converting milligrams to grams.

3. Importance of Molarity Calculation

Details: Molarity is essential for preparing solutions with precise concentrations, performing chemical reactions with accurate stoichiometry, and comparing concentrations of different substances.

4. Using the Calculator

Tips: Enter the concentration in mg/L and the molecular weight in g/mol. Both values must be positive numbers. The calculator will automatically compute the molarity in mol/L.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between molarity and molality?
A: Molarity is moles per liter of solution, while molality is moles per kilogram of solvent. Molarity is temperature-dependent (volume changes with temperature), while molality is not.

Q2: How do I find the molecular weight of a compound?
A: Sum the atomic weights of all atoms in the molecule. For example, water (H₂O) has MW = (2×1.008) + 15.999 = 18.015 g/mol.

Q3: Why multiply by 1000 in the formula?
A: This converts milligrams to grams (1 g = 1000 mg) to match the grams in the molecular weight unit.

Q4: Can I use this for mixtures?
A: This calculates molarity for a single solute. For mixtures, you'd need to calculate each component separately.

Q5: What about very dilute solutions?
A: For very low concentrations, results may be in mmol/L (millimolar) or µmol/L (micromolar) - just multiply by 1000 or 1,000,000 respectively.