Question

Given the balanced equation representing a reaction: 4Al(s) + 3O2(g) → 2Al2O3(s) How many moles of Al(s) react completely with 4.50 moles of O2(g) to produce 3.00 moles of Al2O3(s)?

Answer 1

We must consider the relation between Al and
`O_2`:


`(3\ mol\ O_2)/(4\ mol\ Al) = (4,5\ mol\ O_2)/(x)\ \to\ x = (4,5\ mol\ O_2\cdot 4\ mol\ Al)/(3\ mol\ O_2) = \bf 6\ mol\ Al`

As you can see, the number of moles of Al is double to the number of moles of
`Al_2O_3`, keeping constant the proportion of both substances.