Use the coefficients in the balanced equation to convert anything to anything.
17.7 g H2O x (1 mol C3H8/4 mols H2O) = 17.7 x 1/4 = ? mols C3H8.
Then g propane = mols propane x molar mass propane.
17.7 g H2O x (1 mol C3H8/4 mols H2O) = 17.7 x 1/4 = ? mols C3H8.
Then g propane = mols propane x molar mass propane.
In this case, the balanced equation is:
C3H8(g) + 5O2(g) ā 3CO2(g) + 4H2O(g)
From the equation, we can see that for every 3 moles of CO2 produced, 1 mole of C3H8 is consumed. This means the ratio of moles of C3H8 to moles of CO2 is 1:3.
To convert the given mass of water (17.7 g) to moles, we need to use the molar mass of water. The molar mass of water (H2O) is 18 g/mol (2 g/mol for hydrogen and 16 g/mol for oxygen).
Moles of water = Mass of water / Molar mass of water
Moles of water = 17.7 g / 18 g/mol
Moles of water = 0.983 mol
Using the mole ratio, we can now calculate the moles of propane consumed:
Moles of C3H8 = Moles of water * (Moles of C3H8 / Moles of water)
Moles of C3H8 = 0.983 mol * (1 mol C3H8 / 4 mol H2O)
Moles of C3H8 = 0.24575 mol
Finally, we can convert moles of C3H8 to grams:
Mass of C3H8 = Moles of C3H8 * Molar mass of C3H8
Mass of C3H8 = 0.24575 mol * 44 g/mol (molar mass of C3H8)
Mass of C3H8 = 10.805 g
Therefore, the number of grams of propane consumed is approximately 10.805 g.