1. What is Molarity from Density?

Molarity (M) is a measure of concentration defined as moles of solute per liter of solution. For pure substances, it can be calculated directly from density and molecular weight.

2. How Does the Calculator Work?

The calculator uses the molarity formula:

Where:

• \( M \) — Molarity (mol/L)
• \( Density \) — Density of the substance (g/mL)
• \( MW \) — Molecular weight of the substance (g/mol)

Explanation: The formula converts density from g/mL to g/L (by multiplying by 1000) and then divides by molecular weight to get moles per liter.

3. Importance of Molarity Calculation

Details: Molarity is crucial for preparing solutions in chemistry, biology, and medicine. Accurate concentration measurements are essential for experiments, drug formulations, and industrial processes.

4. Using the Calculator

Tips: Enter density in g/mL and molecular weight in g/mol. Both values must be positive numbers. This calculation is most accurate for pure substances.

5. Frequently Asked Questions (FAQ)

Q1: Can this be used for solutions?
A: This formula is for pure substances. For solutions, you need to know the percentage purity or concentration of the solute.

Q2: Why multiply density by 1000?
A: This converts g/mL to g/L (since there are 1000 mL in 1 L), matching the liter unit in molarity (mol/L).

Q3: What are typical molarity values?
A: For common liquids: Water ~55.5 M, Ethanol ~17.1 M, Acetic Acid ~17.4 M (at room temperature).

Q4: Does temperature affect this calculation?
A: Yes, since density changes with temperature. Use density values measured at the same temperature as your application.

Q5: How accurate is this method?
A: Very accurate for pure substances if precise density and molecular weight values are used. Less accurate for mixtures.