Question

balance the following equation:

c₈h₁₈ + o₂ → co₂ + h₂o

select the correct answer below:

c₈h₁₈ + o₂ → co₂ + h₂o

c₈h₁₈ + 25o₂ → 8co₂ + 9h₂o

2c₈h₁₈ + 25o₂ → 16co₂ + 18h₂o

c₈h₁₈ + o₂ → 4co₂ + 8h₂o

Explanation:

Step1: Balance carbon atoms

In \(\mathrm{C_8H_{18}}\), there are 8 carbon atoms. In \(\mathrm{CO_2}\), if we assume the coefficient of \(\mathrm{C_8H_{18}}\) is \(a\) and of \(\mathrm{CO_2}\) is \(b\), from carbon balance \(8a=b\).

Step2: Balance hydrogen atoms

In \(\mathrm{C_8H_{18}}\), there are 18 hydrogen atoms. In \(\mathrm{H_2O}\), if the coefficient of \(\mathrm{C_8H_{18}}\) is \(a\) and of \(\mathrm{H_2O}\) is \(c\), from hydrogen balance \(18a = 2c\), so \(c = 9a\).

Step3: Balance oxygen atoms

In \(\mathrm{O_2}\), if the coefficient of \(\mathrm{O_2}\) is \(d\), from oxygen balance \(2d=2b + c\). Substitute \(b = 8a\) and \(c=9a\) into \(2d=2b + c\), we get \(2d=16a+9a=25a\). Let \(a = 2\) (to make all coefficients integers), then \(b=16\), \(c = 18\), \(d = 25\)

So the balanced equation is \(2\mathrm{C_8H_{18}} + 25\mathrm{O_2} \longrightarrow 16\mathrm{CO_2} + 18\mathrm{H_2O}\)

Answer:

C. \(2\mathrm{C_8H_{18}} + 25\mathrm{O_2} \longrightarrow 16\mathrm{CO_2} + 18\mathrm{H_2O}\)