Question

N2 + 2O2 → N2O4If 47.6 grams of N2O4 was produced, how many moles of O2 were required?

Answer 1

From the equation of reaction, 2 moles of O₂ reacted to produce N₂O₄.

Using moles-mass-molar mass relationship

`\begin{gathered} n=\frac{mass}{molar\text{ mass}} \\ \end{gathered}`

Let's find the mass of O₂ in the equation of reaction.

`\begin{gathered} n=\frac{\text{mass}}{\text{molar mass}} \\ 2=\frac{\text{mass}}{16} \\ \text{mass}=32g \end{gathered}`

Mass of N₂O₄ in the equation of reaction.

`\begin{gathered} n=\frac{\text{mass}}{\text{molar mass}} \\ 1=\frac{\text{mass}}{92} \\ \text{mass = 92g} \end{gathered}`

from the calculation above, 32g of O₂ produce 92g of N₂O₄

x g of O₂ will produce 47.6g of N₂O₄

cross multiply both sides and make x the subject of formula.

`\begin{gathered} x=(32*47.6)/(92) \\ x=16.56g \end{gathered}`

From the calculations above, 16.56g of O₂ will produce 47.6g of N₂O₄.