Answer
a.
$2 C_2H_6(g) + 7 O_2(g) \longrightarrow 4 CO_2(g) + 6 H_2O(l) + energy$
b.
$2 C_3H_6(g) + 9 O_2(g) \longrightarrow 6 CO_2(g) + 6 H_2O(l) + energy$
c.
$2 C_8H_{18}(g) + 25 O_2(g) \longrightarrow 16 CO_2(g) + 18 H_2O(l) + energy$
Work Step by Step
1. Write the chemical equation for the combustion of each alkane.
- They will follow this pattern: $$Alkane + aO_2(g) \longrightarrow bCO_2(g) + cH_2O(l) + energy$$
b = number of carbon on the alkane.
c = number of hydrogens on the alkane divided by 2.
a = b + $c/2$
a. $C_2H_6(g) + \frac{7}{2}O_2(g) \longrightarrow 2 CO_2(g) + 3 H_2O(l) + energy$
$2 C_2H_6(g) + 7 O_2(g) \longrightarrow 4 CO_2(g) + 6 H_2O(l) + energy$
b. $C_3H_6(g) + \frac{9}{2}O_2(g) \longrightarrow 3 CO_2(g) + 3 H_2O(l) + energy$
$2 C_3H_6(g) + 9 O_2(g) \longrightarrow 6 CO_2(g) + 6 H_2O(l) + energy$
c. $C_8H_{18}(g) + \frac{25}{2}O_2(g) \longrightarrow 8 CO_2(g) + 9 H_2O(l) + energy$
$2 C_8H_{18}(g) + 25 O_2(g) \longrightarrow 16 CO_2(g) + 18 H_2O(l) + energy$
