Acetone is a highly common organic compound frequently encountered in industrial and household settings. Understanding its precise molecular weight, or molar mass, is fundamental to chemistry. This analysis defines molar mass and systematically determines the specific mass of one mole of acetone.
The Chemical Identity of Acetone
Acetone is an organic compound known chemically as propanone or dimethyl ketone. It is the simplest member of the ketone family, characterized by a carbonyl group—a carbon atom double-bonded to an oxygen atom—positioned between two methyl groups (CH3). Its condensed chemical formula is CH3COCH3, which is simplified to the molecular formula C3H6O.
The formula C3H6O indicates that each molecule contains three Carbon atoms, six Hydrogen atoms, and one Oxygen atom. Acetone is valued as an effective solvent due to its ability to dissolve a wide array of organic substances, making it the active ingredient in many nail polish removers and industrial cleaning agents.
Defining Molar Mass
Molar mass links the microscopic world of atoms and molecules to macroscopic laboratory measurements. It is defined as the mass in grams of one mole of a substance, and its standard unit is grams per mole (g/mol). A mole represents a specific number of particles, approximately \(6.022 \times 10^{23}\) particles, known as Avogadro’s number.
When calculating molar mass, chemists utilize the atomic weights listed on the periodic table, which are expressed in atomic mass units (amu). The numerical value of an element’s atomic weight in amu is identical to the mass of one mole of that element in grams. The molar mass of a compound is the sum of the molar masses of all the constituent atoms shown in its chemical formula.
Step-by-Step Calculation and Final Value
Determining acetone’s molar mass requires summing the masses of the atoms specified in its chemical formula, C3H6O. We use the standard atomic weights for the three elements: Carbon (C), Hydrogen (H), and Oxygen (O). The established values are approximately \(12.01\) g/mol for C, \(1.008\) g/mol for H, and \(16.00\) g/mol for O.
We multiply the molar mass of each element by the number of times it appears in the molecule. The three Carbon atoms contribute \(3 \times 12.01\) g/mol, totaling \(36.03\) g/mol. The six Hydrogen atoms contribute \(6 \times 1.008\) g/mol, resulting in \(6.048\) g/mol. The single Oxygen atom contributes \(1 \times 16.00\) g/mol, which is \(16.00\) g/mol.
The total molar mass is found by adding these three component masses: \(36.03\) g/mol (Carbon) + \(6.048\) g/mol (Hydrogen) + \(16.00\) g/mol (Oxygen). This summation yields a value of \(58.078\) g/mol. Rounding this figure to two decimal places, the molar mass of acetone (C3H6O) is \(58.08\) g/mol.