Final answer:
To find the moles of propane from 67.7 g, divide the mass by the molar mass (44.10 g/mol) of propane, resulting in approximately 1.535 moles.
Step-by-step explanation:
To calculate the moles of propane, which has a molecular formula of C3H8, we start with the provided mass of propane, 67.7 g. The molar mass of propane is the sum of the molar masses of its individual elements: 3 moles of carbon (C) at 12.01 g/mol each plus 8 moles of hydrogen (H) at 1.01 g/mol each, giving us a molar mass of 44.10 g/mol for propane.
We use the formula:
moles of compound = mass of the compound (g) / molar mass of compound (g/mol)
Therefore, the moles of propane (C3H8) are:
moles of C3H8 = 67.7 g / 44.10 g/mol = 1.535 moles (rounded to three decimal places)