Question

For the given reaction, if we have 4 moles of C3H8 and 10 moles of O2, which is the limiting reactant?C3H8 + 5 O2 → 4 H2O + 3 CO2Select one:a.H2Ob.O2c.C3H8d.CO2

Answer 1

Chemistry => Stoichiometry => Limiting Reactant

The limiting reactant is the reactant that will produce the fewest moles of product, or in other words, it will be the reactant that will be completely consumed.

To find the limiting reactant we must divide the moles of the reactants by their respective stoichiometric coefficient of the balanced equation of the reaction.

We first verify that the equation is balanced by counting the number of atoms of each element on both sides of the reaction, we have on each side of the reaction:

3 carbons

8 hydrogen

10 oxygen

The equation is balanced, so we can continue with the calculation. We have:

`\begin{gathered} C_3H_8\rightarrow(Moles)/(StoichiometricCoefficient) \\ \\ C_3H_8\rightarrow(4)/(1)=4 \end{gathered}`
`\begin{gathered} O_2\rightarrow(Moles)/(StoichiometricCoefficient) \\ \\ O_2\rightarrow(10)/(5)=2 \end{gathered}`

The limiting reactant is the one with the lowest quotient value, that is, in this case, our limiting reactant is oxygen.

Answer: b. O2