If a combustion chamber containing propane (C3H8; GFM = 44.1 g/mol) gas had 79.9 g C3H8, what is the mass contributed by carbon (in grams) in this propane sample?
C3 = 12*3 = 36
79g * 36/44.1 = ____ g
To find the mass contributed by carbon in the propane sample, we need to determine the number of moles of C3H8 and then calculate the mass of carbon.
First, we need to calculate the moles of C3H8 in the sample using its molar mass (GFM = 44.1 g/mol) and the given mass of propane (79.9 g):
Moles of C3H8 = Mass of C3H8 / Molar mass of C3H8
Moles of C3H8 = 79.9 g / 44.1 g/mol
Now, we can use the molecular formula of propane (C3H8) to determine the ratio of carbon atoms to the molar mass of C3H8. The molecular formula of propane suggests that one molecule of C3H8 contains three carbon atoms.
Mass of carbon = Moles of C3H8 x (Molar mass of carbon / Molecular ratio of carbon in C3H8)
Mass of carbon = (79.9 g / 44.1 g/mol) x (12.01 g/mol / 3)
Calculating this expression, we find:
Mass of carbon = 137.3 g
Therefore, the mass contributed by carbon in the propane sample is 137.3 grams.