Molar Mass of C₈H₁₈

Octane. A model compound for petrol (gasoline) in combustion problems.

Molar mass of C8H18
114.232 g/mol
8 × 12.011 + 18 × 1.008 = 114.232

Calculation, element by element

ElementAtomsAtomic mass (g/mol)SubtotalMass %
Carbon (C)812.01196.08884.12%
Hydrogen (H)181.00818.14415.88%
Total114.232100%

= 0.087541 mol = 5.2719 × 1022 formula units

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C₈H₁₈ molar mass FAQ

What is the molar mass of octane (C₈H₁₈)?

114.232 g/mol. It is the sum of the atomic masses of every atom in the formula: 8 × 12.011 + 18 × 1.008 = 114.232 g/mol.

How many grams are in one mole of C₈H₁₈?

114.232 g. Molar mass is the mass of one mole (6.022 × 10²³ formula units), so 1 mol of C₈H₁₈ weighs 114.232 g and 0.5 mol weighs 57.116 g.

How many moles are in 10 g of C₈H₁₈?

10 g ÷ 114.232 g/mol = 0.08754 mol.

What is the percent composition of C₈H₁₈?

Carbon 84.12%, Hydrogen 15.88%.

Is molecular weight the same as molar mass for C₈H₁₈?

Numerically yes: the molecular (or formula) weight is 114.232 u per formula unit, and the molar mass is 114.232 g/mol.

Molar masses of other common compounds