Molarity
Definition
A measure of solution concentration defined as moles of solute per liter of solution (mol/L or M).
Why is Molarity Important?
Molarity is an essential chemistry concept used in laboratories, pharmaceutical development, environmental science, and industrial processes. Understanding this concept is critical for accurate chemical calculations, safe laboratory practices, and optimizing reactions.
Our chemistry calculators provide instant, accurate results for complex conversions and calculations, making lab work more efficient and reducing the risk of errors in critical measurements.
What is Molarity?
Molarity (M) is the most common measure of solution concentration, defined as the number of moles of solute per liter of solution: M = mol/L. A 1 M (one molar) solution contains 1 mole of solute in 1 liter of total solution.
How to Calculate Molarity
M = moles of solute / liters of solution
Preparing a Solution Example
Make 500 mL of 0.1 M NaCl solution:
| Step | Calculation |
|---|---|
| 1. Find moles needed | 0.1 mol/L ร 0.5 L = 0.05 mol |
| 2. Convert to grams | 0.05 mol ร 58.44 g/mol = 2.922 g |
| 3. Dissolve in water | Dissolve 2.922 g NaCl in water, bring total volume to 500 mL |
Common Solution Concentrations
| Solution | Approximate Molarity |
|---|---|
| Seawater NaCl | ~0.6 M |
| Saline IV solution | 0.154 M (0.9% NaCl) |
| Household bleach (NaClO) | ~0.8 M (5.25%) |
| Hydrochloric acid (conc.) | ~12 M |
| Sulfuric acid (conc.) | ~18 M |
| Blood glucose (normal) | ~0.005 M (5 mM) |