posted by Danielle
A small bottle of propane gas (C3H8) contains 400.0 grams of propane. When the propane is burned in oxygen, how many moles of each product are formed?
first write the balanced chemical equation:
C3H8 + 5O2 -> 3CO2 + 4H2O
**note: in combustion reaction of organic compounds, the usual products are carbon dioxide and water.
then calculate for molecular weight of propane (the C3H8),, Carbon is 12 while H is 1:
3*12 + 8*1 = 44 g/mol
since initially we have 400 g of propane, we divide this by the molecular weight to get the number of moles of propane:
400 g / 44 g/mol = 9.09 mol C3H8
now we can use this to get the number of moles of each product (the CO2 and H2O) formed:
for CO2 : 9.09 mol C3H8 * 3 mol CO2 / 1 mol C3H8 = 27.27 mol CO2
for H2O : 9.09 mol C3H8 * 4 mol H2O / 1 mol CO2 = 36.36 mol H2O
hope this helps~ :)