Question

how many grams of aluminium, al, would be required to react with 4 moles aluminium oxide, al₂o₃?
4al + 3o₂ → 2al₂o₃
molar mass al: 27 g/mol
? g al

Explanation:

Step1: Determine the mole ratio of Al to Al₂O₃

From the balanced chemical equation \(4Al + 3O_2
ightarrow2Al_2O_3\), the mole ratio of \(Al\) to \(Al_2O_3\) is \(4:2 = 2:1\).

Step2: Calculate the moles of Al needed

If there are \(n(Al_2O_3)=4\space mol\), using the mole ratio, \(n(Al)=2\times n(Al_2O_3)\). So \(n(Al)=2\times4\space mol = 8\space mol\).

Step3: Calculate the mass of Al

Using the formula \(m = n\times M\) (where \(M\) is molar mass and \(n\) is the number of moles), with \(M(Al) = 27\space g/mol\) and \(n(Al)=8\space mol\). Then \(m(Al)=8\space mol\times27\space g/mol\)

Answer:

\(216\space g\)