Molar Mass of Octane
C8H18 — 114.232 g/mol, worked out element by element.
Molar mass of Octane, C₈H₁₈
114.232 g/mol
Molecular weight 114.232 · 26 atoms per formula unit
Also known as: c8h18.
The reference hydrocarbon for petrol, and a long combustion equation to balance.
How 114.232 g/mol is worked out
| Element | Atoms | Atomic mass | Mass | % of total |
|---|---|---|---|---|
| Carbon | 8 | 12.011 | 96.088 | 84.12% |
| Hydrogen | 18 | 1.008 | 18.144 | 15.88% |
| Total | 26 | 114.232 | 100% |
M = 8 × 12.011 + 18 × 1.008 = 114.232 g/mol
Grams to moles for Octane
| Mass | Moles | Formula units |
|---|---|---|
| 1 g | 0.0088 mol | 5.272 × 10^21 |
| 10 g | 0.0875 mol | 5.272 × 10^22 |
| 25 g | 0.2189 mol | 1.318 × 10^23 |
| 50 g | 0.4377 mol | 2.636 × 10^23 |
| 100 g | 0.8754 mol | 5.272 × 10^23 |
| 250 g | 2.1885 mol | 1.318 × 10^24 |
| 114.232 g | 1 mol | 6.022 × 10^23 |
For any other amount, use the molar mass calculator, or the molarity calculator to make up a solution of a given concentration.
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Frequently Asked Questions
What is the molar mass of Octane?
The molar mass of Octane (C8H18) is 114.232 g/mol. That is the sum of the standard atomic weights of all 26 atoms in one formula unit: 8 × 12.011 + 18 × 1.008 = 114.232.
What is the molecular weight of Octane?
114.232 — the same number as the molar mass, but as a dimensionless ratio rather than in g/mol. The two terms describe the same arithmetic, so a molecular weight of 114.23 and a molar mass of 114.23 g/mol are the same answer.
How many moles are in 100 g of Octane?
100 ÷ 114.232 = 0.8754 mol. To convert any mass to moles, divide by the molar mass; to go the other way, multiply.
What is the percent composition of Octane?
By mass, Octane is 84.12% carbon, 15.88% hydrogen. Each element's share is its total mass in the formula divided by 114.232.
How many atoms are in one formula unit of Octane?
26: 8 carbon, 18 hydrogen. One mole contains 6.02214076 × 10²³ formula units, so a mole of Octane contains 26 × 6.022 × 10²³ atoms in total.