Question

Aluminum reacts with oxygen to produce aluminum oxide. 4 Al(s) + 3 O2(g) → 2 Al2O3(s) If 5.0 moles of Al react with excess O2, how many moles of Al2O3 can be formed? a) 1.0 mol b) 2.5 mol c) 2.0 mol d) 5.0 mol

Answer 1

Answer:

2.5 mol

Explanation:

Here, in the given reaction since O2 is in excess therefore Al is limiting reagent. So, moles of Aluminium Oxide formed is (5/4)*2=5/2=2.5 mol.

Answer 2

Given: Aluminum reacts with oxygen to produce aluminium oxide. 5.0 moles of Al react with excess O2.

To find: We have to find the moles of aluminium oxide formed.

Solution:

The given reaction is-

$4Al+3O_2\rightarrow 2Al_2O_3$.

Here four moles of aluminium reacts with three moles of oxygen gas to form two moles of aluminium oxide.

Thus 4 moles of aluminium reacts to form two moles of aluminium oxide.

So, 5.0 moles of aluminium will react to form 5×2/4=2.5 moles of aluminium oxide.

2.5 moles of aluminium oxide is formed.

Hence the correct option is b.