Oops I posted the right question but wrong answer options...
What mass of propane (C3H8) is needed to produce 346g carbon dioxide in the following reaction?
C3H8(g)+5O2(g)->3CO2(g)+4H2O(g)
A. 346g C3H8
B. 115g C3H8
C. 5075g C3H8
D. 1.86g C3H8
You have the equation.
Convert 346 g CO2 to mols. mols = grams/molar mass.
Use the coefficients in the balanced equation to convert mols CO2 to mols propane.
Now convert mols propane to grams. g = mols x molar mass
To solve this problem, we need to use stoichiometry, which is a way to relate the quantities of substances involved in a chemical reaction. In this case, we are given the mass of carbon dioxide (CO2) produced and asked to find the mass of propane (C3H8) required.
The balanced chemical equation provided shows that 1 mole of C3H8 produces 3 moles of CO2. To find the moles of CO2 produced from the given mass of 346g, we need to convert grams to moles using the molar mass of CO2.
1. Calculate the molar mass of CO2:
C = 1 atom x 12.01 g/mol = 12.01 g/mol
O = 2 atoms x 16.00 g/mol = 32.00 g/mol
Total molar mass = 12.01 g/mol + 32.00 g/mol = 44.01 g/mol
2. Convert the mass of CO2 to moles:
346 g CO2 x (1 mol/44.01 g) ≈ 7.86 mol CO2
Since the stoichiometry of the reaction tells us that 1 mole of C3H8 produces 3 moles of CO2, we can use this ratio to find the moles of C3H8 required.
3. Set up a proportion:
1 mol C3H8 / 3 mol CO2 = x mol C3H8 / 7.86 mol CO2
4. Solve for x (moles of C3H8):
x = 7.86 mol CO2 x (1 mol C3H8 / 3 mol CO2) ≈ 2.62 mol C3H8
Finally, to find the mass of C3H8 required, we multiply the moles of C3H8 by its molar mass:
2.62 mol C3H8 x (44.10 g/mol) ≈ 115.2 g C3H8
Therefore, the correct answer is B. 115g C3H8.