Grams to Moles Calculator
Convert between grams and moles using molar mass. Calculate molecular quantities for chemistry problems and stoichiometry
Calculate Grams ⇄ Moles Conversion
Formula: H₂O
Molar Mass: 18.015 g/mol
Weight of your sample in grams
Conversion Results
Calculation Details
Given: Mass = 0 g, Molar Mass = 18.015 g/mol
Formula: moles = mass ÷ molar mass
Calculation: 0.0000 mol = 0 g ÷ 18.015 g/mol
Particles: 0.000e+0 molecules/atoms
Example Calculation
Water Conversion Example
Problem: How many moles are in 100 grams of water?
Given: Mass = 100 g, Water (H₂O)
Molar Mass of H₂O: (2 × 1.008) + 15.999 = 18.015 g/mol
Step-by-Step Solution
Step 1: Identify the formula: n = m / M
Step 2: Substitute values: n = 100 g / 18.015 g/mol
Step 3: Calculate: n = 5.551 moles
Answer: 100 grams of water contains 5.551 moles
Molecules: 5.551 × 6.022 × 10²³ = 3.342 × 10²⁴ molecules
Key Concepts
Mole
6.022 × 10²³ particles
SI unit for amount of substance
Molar Mass
Mass per mole (g/mol)
Sum of atomic masses
Avogadro's Number
6.022 × 10²³
Particles per mole
Conversion Formulas
Grams to Moles
n = m / M
moles = mass ÷ molar mass
Moles to Grams
m = n × M
mass = moles × molar mass
Particles
N = n × Nₐ
particles = moles × Avogadro's
Understanding Grams to Moles Conversion
What is a Mole?
A mole is the SI unit for measuring the amount of a substance. One mole contains exactly 6.02214076 × 10²³ elementary entities (atoms, molecules, ions, etc.). This number is known as Avogadro's number.
Why Use Moles?
- •Relates mass to number of particles
- •Essential for stoichiometry calculations
- •Connects atomic scale to laboratory scale
- •Used in chemical equation balancing
Molar Mass
Molar mass is the mass of one mole of a substance, expressed in grams per mole (g/mol). It equals the relative atomic or molecular mass but with units of g/mol.
Calculating Molar Mass
For compounds, sum the atomic masses:
H₂O: (2 × 1.008) + 15.999 = 18.015 g/mol
Use values from the periodic table for accuracy.