Given this equation. C3H8 + 5O2 -> CO2 + H2O.

Question

How many moles of O2 will be needed to comepletely burn 1.75 moles of propane C3H8?

Answer 1

First, balance the equation.
C3H8 + 5O2 -> 3CO2 +4H2O.

Use the coefficients to convert mols propane to mols O2 this way.
1.75 mols C3H8 x (5 mols O2/1 mol C3H8) = 1.75 x 5/1 = ?