Molar Mass Calculator

Molar Mass Calculator - Calculate Mass of Chemical Compounds

⚗️ Calculate molar mass of chemical compounds including sodium oxide (Na₂O), water (H₂O), and thousands of other substances. Convert between mass, moles, and number of molecules.

What is Molar Mass?

Molar mass is the mass of one mole of a substance, expressed in grams per mole (g/mol). It equals the sum of the atomic masses of all atoms in the chemical formula.

Sodium Oxide (Na₂O) Calculation

Formula: Na₂O

• Sodium (Na): 2 atoms × 22.99 g/mol = 45.98 g/mol
• Oxygen (O): 1 atom × 16.00 g/mol = 16.00 g/mol
• Total Molar Mass: 45.98 + 16.00 = 61.98 g/mol

Mass Percentage Composition

• Sodium (Na): (45.98 / 61.98) × 100% = 74.19%
• Oxygen (O): (16.00 / 61.98) × 100% = 25.81%

Key Formulas

Moles to Mass: mass (g) = moles × molar mass (g/mol)

Mass to Moles: moles = mass (g) / molar mass (g/mol)

Molecules: number = moles × 6.022 × 10²³ (Avogadro's number)

Atomic Masses (Rounded)

• Hydrogen (H): 1.008 g/mol
• Carbon (C): 12.01 g/mol
• Nitrogen (N): 14.01 g/mol
• Oxygen (O): 16.00 g/mol
• Sodium (Na): 22.99 g/mol
• Magnesium (Mg): 24.31 g/mol
• Sulfur (S): 32.07 g/mol
• Chlorine (Cl): 35.45 g/mol
• Calcium (Ca): 40.08 g/mol
• Iron (Fe): 55.85 g/mol

Calculation Examples

Example 1: Mass of 2 moles of Na₂O

• Molar mass of Na₂O = 61.98 g/mol
• Mass = 2 mol × 61.98 g/mol = 123.96 g

Example 2: Moles in 100g of H₂O

• Molar mass of H₂O = 18.02 g/mol
• Moles = 100 g / 18.02 g/mol = 5.55 mol

Example 3: Molecules in 1 mole of NaCl

• Number = 1 mol × 6.022 × 10²³ = 6.022 × 10²³ molecules

Common Compounds and Their Uses

• Na₂O (Sodium Oxide): Glass production, ceramics, chemical synthesis
• H₂O (Water): Universal solvent, essential for life
• NaCl (Sodium Chloride): Table salt, food preservation, de-icing
• H₂SO₄ (Sulfuric Acid): Fertilizers, batteries, chemical industry
• CaCO₃ (Calcium Carbonate): Construction, antacids, supplements
• NH₃ (Ammonia): Fertilizers, cleaning products, refrigeration
• CH₃COOH (Acetic Acid): Vinegar, food preservation
• C₆H₁₂O₆ (Glucose): Energy source, metabolism

Tips for Calculating Molar Mass

• Subscripts: Multiply atomic mass by the subscript number (H₂ = 2 × 1.008)
• Parentheses: Multiply everything inside by the outside number (Ca(OH)₂ = Ca + 2×O + 2×H)
• Multiple Elements: Add all atomic masses together
• Precision: Use at least 2 decimal places for accuracy
• Units: Always express in g/mol

Real-World Applications

• Medicine: Calculating drug dosages based on molecular weight
• Industry: Determining quantities for chemical reactions
• Food Science: Nutritional calculations and fortification
• Environmental: Pollution measurements and control
• Research: Stoichiometry and experimental design

💡 Pro Tip: When calculating molar mass for compounds with parentheses like Ca(OH)₂, remember to multiply EVERYTHING inside the parentheses by the subscript outside. So Ca(OH)₂ = Ca + 2×O + 2×H = 40.08 + (2×16.00) + (2×1.008) = 74.096 g/mol. Don't forget the hydrogen atoms!