Mole Calculator
Convert between grams, moles, and molecules using molar mass. Supports g, kg, scientific notation.
Results
Mass
0.000 g
Moles
0.000000 mol
Molecules
0
Mole Conversion Formulas
Understanding the relationships between mass, moles, and molecules
Key Formulas
Moles from Mass:
moles = mass(g) / molar mass
Mass from Moles:
mass(g) = moles × molar mass
Molecules from Moles:
molecules = moles × NA
Avogadro's Constant:
NA = 6.022 × 1023 mol-1
Worked Example
Problem:
Calculate moles and molecules in 5.0 g of glucose (C₆H₁₂O₆)
Given:
Mass = 5.0 g
Molar mass of glucose = 180.16 g/mol
Step 1: Calculate moles
moles = 5.0 g ÷ 180.16 g/mol = 0.02775 mol
Step 2: Calculate molecules
molecules = 0.02775 mol × 6.022×10²³
= 1.67 × 10²² molecules
What is a Mole?
Understanding the fundamental unit of chemistry
Counting Unit
A mole is a counting unit like a dozen, but much larger. One mole contains 6.022 × 10²³ particles (atoms, molecules, ions, etc.).
Mass Connection
Molar mass connects moles to grams. It's the mass of one mole of a substance, expressed in g/mol, and equals the atomic/molecular weight.
Avogadro's Number
Named after Amedeo Avogadro, this constant (6.022 × 10²³) bridges the microscopic world of atoms with the macroscopic world we can measure.
Where is it Used?
Mole calculations are essential across many fields of science and industry
Stoichiometry
Calculate reactant and product quantities in chemical reactions using balanced equations.
Reagent Preparation
Prepare solutions with precise concentrations for laboratory experiments and analysis.
Gas Law Problems
Apply ideal gas law (PV = nRT) to relate pressure, volume, temperature, and moles.
Pharmaceuticals
Calculate drug dosages and active ingredient concentrations in medications.
Environmental Testing
Measure pollutant concentrations and assess environmental impact of chemicals.
Industrial Chemistry
Scale up reactions from lab to production and optimize manufacturing processes.
Frequently Asked Questions
Common questions about mole calculations and conversions
How do I find molar mass?
Molar mass is found by adding up the atomic masses of all atoms in a molecule. For example, water (H₂O) has a molar mass of 18.02 g/mol: (2 × 1.008) + (1 × 15.999) = 18.015 g/mol. You can find atomic masses on the periodic table.
What's the difference between molecules and atoms?
Atoms are individual elements (like H, O, C), while molecules are groups of atoms bonded together (like H₂O, CO₂, C₆H₁₂O₆). When calculating particles using Avogadro's number, you get the number of formula units - atoms for elements, molecules for compounds.
Why do we use scientific notation for molecules?
The number of molecules in even small amounts is enormous. For example, 1 gram of water contains about 3.34 × 10²² molecules. Scientific notation makes these huge numbers manageable and easier to read and compare.
What's the difference between moles and molarity?
Moles (mol) is a unit of amount - how much substance you have. Molarity (M) is a concentration unit - moles of solute per liter of solution. Think of moles as 'how many' and molarity as 'how concentrated'.
Can I use this calculator for any substance?
Yes! This calculator works for any substance as long as you know its molar mass. Whether it's an element (like carbon, 12.01 g/mol), a simple compound (like NaCl, 58.44 g/mol), or a complex molecule (like glucose, 180.16 g/mol).
What if I have a mixture of substances?
This calculator is designed for pure substances. For mixtures, you'd need to calculate each component separately or use the average molar mass if you know the composition. Consider each substance individually for accurate results.