Answer
The balanced equation is:
$2C_6H_{14}(g) + 19O_2(g) -- \gt 12CO_2(g) + 14H_2O(g)$
The number of moles of oxygen gas that are required to react completely with 7.2 moles of hexane is equal to 68 moles $(O_2)$.
Work Step by Step
1. Balance the equation:
- Start by balancing the number of carbons:
$C_6H_{14}(g) + O_2(g) -- \gt 6CO_2(g) + H_2O(g)$
- Balance the number of hydrogens:
$C_6H_{14}(g) + O_2(g) -- \gt 6CO_2(g) + 7H_2O(g)$
- There is a total of 6*2 + 7 = 19 oxygens on the products side, so:
$C_6H_{14}(g) + \frac{19}{2}O_2(g) -- \gt 6CO_2(g) + 7H_2O(g)$
Multiply all the coefficients by 2:
$2C_6H_{14}(g) + 19O_2(g) -- \gt 12CO_2(g) + 14H_2O(g)$
2. Now, use the coefficients to calculate the number of moles $(O_2)$.
$7.2 moles (C_6H_{14}) \times \frac{19 mol(O_2)}{2mol(C_6H_{14})} = 68\ moles (O_2)$
