Question

aluminum reacts with oxygen to produce aluminum oxide according to the reactions below.

4 al(s) + 3 o₂(g) → 2 al₂o₃(s)

if the reaction occurs at stp, what volume of oxygen gas will react with 1.87 g al?

first drag the steps of the process in the correct order in the activity below.

perform the calculation.

if the reaction occurs at stp, what volume of oxygen gas will react with 1.87 g al?

1.16 l

1.66 l

1.55 l

2.07 l

Explanation:

Step1: Convert grams of Al to moles

The molar mass of Al is \(26.98\space g/mol\).
\(n_{Al}=\frac{1.87\space g}{26.98\space g/mol}\approx0.0693\space mol\)

Step2: Use mole ratio from balanced equation

From \(4Al(s)+3O_{2}(g)\to2Al_{2}O_{3}(s)\), the mole ratio of \(Al\) to \(O_{2}\) is \(4:3\).
\(n_{O_{2}}=0.0693\space mol\space Al\times\frac{3\space mol\space O_{2}}{4\space mol\space Al}\approx0.0520\space mol\)

Step3: Use ideal gas law at STP (\(V = n\times22.4\space L/mol\))

\(V_{O_{2}}=0.0520\space mol\times22.4\space L/mol\approx1.16\space L\)

Answer:

1.16 L