The Correct Answer and Explanation is:
1.67 moles
To convert the mass of a substance into moles, you must use its molar mass. The molar mass acts as a conversion factor that connects the mass of a substance in grams to its amount in moles.
The first step is to identify the chemical formula for oxygen. In its natural and most stable state, oxygen exists as a diatomic molecule, meaning two oxygen atoms are bonded together. Its chemical formula is O₂. This is an important distinction because using the mass of a single oxygen atom (O) would lead to an incorrect answer.
Next, we determine the molar mass of molecular oxygen (O₂). By consulting the periodic table, we find that the molar mass of a single oxygen atom (O) is approximately 16.00 grams per mole ( g/mol ). Since an oxygen molecule contains two atoms, we calculate its molar mass as follows:
Molar Mass of O₂ = 2 × (Molar Mass of O) = 2 × 16.00 g/mol = 32.00 g/mol .
This means that one mole of oxygen gas has a mass of 32.00 grams.
Now we can use the formula to convert mass to moles:
Moles = Mass / Molar Mass
Plugging in the given values:
Moles = 53.3 g / 32.00 g/mol
Performing the calculation gives:
Moles ≈ 1.665625 mol
The final step is to apply the rules of significant figures. The given mass, 53.3 g, has three significant figures. Therefore, our final answer should also be rounded to three significant figures to reflect the precision of the initial measurement. Rounding 1.665625 to three significant figures gives us 1.67.
Thus, converting 53.3 grams of oxygen to moles will give you 1.67 moles of oxygen (O₂).
