Answer:
11.55 moles of CO2 gas result from 3.85 moles of propane.
15.4 moles of H2O result from 3.85 moles of propane.
b) 0.5176 moles of water result from 0.647 moles of oxygen gas.
0.1294 moles of propane are reacted.
Explanation:

a) Amount of propane = 3.85 moles
The reaction indicates that for every mole of propane, 3 moles of carbon dioxide are produced.
Thus, 3.85 moles of propane yield:
of carbon dioxide.
11.55 moles of CO2 gas result from 3.85 moles of propane.
The reaction also specifies that 1 mole of propane produces 4 moles of water.
Therefore, 3.85 moles of propane will generate:
of water.
15.4 moles of H2O result from 3.85 moles of propane.
b) Amount of oxygen gas = 0.647 moles
The reaction states that 5 moles of oxygen yield 4 moles of water.
As a result, 0.647 moles of oxygen will produce:
of water.
0.5176 moles of water result from 0.647 moles of oxygen gas.
The reaction indicates that 5 moles of oxygen gas interact with 1 mole of propane.
Then, 0.647 moles of oxygen will cause:
of propane to react.
0.1294 moles of propane are reacted.