Molarity Calculator
Calculate the molarity (mol/L) of a solution or rearrange the formula to find moles or volume. Ideal for students and lab professionals.
🧪 Overview: Molarity Calculator for Chemistry & Lab Work
This molarity calculator helps you accurately determine the concentration of a chemical solution using moles, volume, and optional molecular weight. Designed for students, chemists, pharmacists, and laboratory professionals, this tool offers a flexible interface to solve for:
- Molarity (mol/L) based on solute and solution volume
- Moles of solute needed to achieve a target concentration
- Volume required to dilute a known amount of solute to a given molarity
It also optionally calculates the mass of solute in grams when molecular weight is provided — great for practical lab preparations.
All calculations support Liters (L) and Milliliters (mL), making this tool adaptable for both academic and industrial applications.
📐 Formula & Methodology
Basic Molarity Formula:
M = n / V
Where:
M = Molarity (mol/L)
n = Moles of solute (mol)
V = Volume of solution (L)
To find moles of solute:
n = M × V
To find required volume for dilution:
V = n / M
Mass of solute (optional):
grams = moles × molecular weight (g/mol)
These formulas are fundamental in chemistry for preparing solutions, performing dilutions, or calculating concentrations in titration and reaction setups.
🔬 Example Calculation
Scenario: You need to prepare 500 mL of a 0.5 mol/L NaCl solution.
- Volume: 500 mL = 0.5 L
- Molarity: 0.5 mol/L
- Calculation: n = M × V = 0.5 × 0.5 = 0.25 mol
- Optional: If MW = 58.44 g/mol → Grams = 0.25 × 58.44 = 14.61 g
💡 Use Cases
- 🎓 Students solving chemistry homework problems or lab assignments
- 🔬 Lab workers preparing chemical solutions for experiments
- 💊 Pharmacists calculating drug concentrations for solutions
- 👩🏫 Chemistry teachers demonstrating molarity concepts in class
- 🧪 Researchers standardizing solutions for titration or synthesis
❓ Frequently Asked Questions
What is molarity?
Molarity is the number of moles of solute per liter of solution, expressed in mol/L. It represents solution concentration and is widely used in chemistry.
How do I calculate molarity from grams?
First convert grams to moles using the molecular weight (g/mol), then divide by volume in liters. The formula is:M = (grams / MW) / volume
Can I use milliliters (mL) instead of liters?
Yes, enter the volume in mL and the calculator automatically converts it to liters before performing the calculation.
What unit is molarity measured in?
Molarity is always measured in mol/L (moles per liter), even if input volume is given in mL.
What is molecular weight and how is it used?
Molecular weight (MW) is the mass of one mole of a substance, in grams. It's used to convert between grams and moles of a compound.
Can I calculate moles or volume with this tool?
Yes! Simply change the "What do you want to calculate?" dropdown to switch between molarity, moles, or volume.
Why is molarity important in chemistry?
Molarity allows chemists to control reaction ratios precisely, especially in stoichiometry, titrations, and solution preparation.
What happens if I input 0 or leave fields blank?
The calculator will alert you to enter valid values. Molarity cannot be calculated if volume is zero or missing.
What is a typical molarity range for lab solutions?
Common concentrations range from 0.01 mol/L (very dilute) to 2 mol/L (concentrated), but can vary depending on application.