Question

part b
balance the following equation , and then find the number of moles of o₂ that will generate 1.3 moles of h₂o.
c₃h₈ + o₂ → h₂o + co₂

Explanation:

Step1: Balance the chemical equation

For \(C_3H_8+O_2 - H_2O + CO_2\), balance \(C\) atoms first. There are 3 \(C\) atoms in \(C_3H_8\), so we write \(3CO_2\). Balance \(H\) atoms: there are 8 \(H\) atoms in \(C_3H_8\), so we write \(4H_2O\). Now for \(O\) atoms: on the right - hand side, there are \(3\times2 + 4\times1=10\) \(O\) atoms. So we write \(5O_2\) on the left - hand side. The balanced equation is \(C_3H_8 + 5O_2=3CO_2+4H_2O\).

Step2: Use mole ratio

From the balanced equation \(C_3H_8 + 5O_2=3CO_2+4H_2O\), the mole ratio of \(O_2\) to \(H_2O\) is \(n(O_2):n(H_2O)=5:4\). Let \(n(O_2)\) be the number of moles of \(O_2\) and \(n(H_2O) = 1.3\) mol. Using the ratio \(\frac{n(O_2)}{n(H_2O)}=\frac{5}{4}\), we can solve for \(n(O_2)\).

$$n(O_2)=\frac{5}{4}\times n(H_2O)$$

Substitute \(n(H_2O) = 1.3\) mol into the equation:

$$n(O_2)=\frac{5\times1.3}{4}=\frac{6.5}{4}=1.625$$

Answer:

The balanced equation is \(C_3H_8 + 5O_2=3CO_2+4H_2O\) and the number of moles of \(O_2\) is \(1.625\) mol.