Verified answer

[1] First balance equation

[2] Then find moles

C3H8 + 5O2 ---> 3CO2 +4H2O

So now you know the ratio of propane to the products.

[2] How many moles do you have of propane when you have 4.9 L under those conditions? Use the ideal gas law and solve for n.

pV = nRT

n = (pV)/(RT)

p is given, V is given, R is a constant and T is given (but convert to K)

T = 350 + 273 = 623 K <--- crazy hot!

n = (0.911)(4.9) / (8.314)(623) = 4.4639/5179.6 = 0.0008618 moles propane = 8.62 x 10^-4

Depending on what the rest of the question is, you can use this info to find the moles of products.

question incomplete