How many moles of al2o3 are formed when 0.78 mol o2 reacts with aluminum?

The number of moles of produced will be 0.52 moles.

Explanation:

The chemical equation for the production of aluminium oxide form aluminium and oxygen follows the equation:

By stoichiometry of the reaction:

3 moles of oxygen gas produces 2 moles of aluminium oxide.

So, 0.78 moles of oxygen gas will produce = moles of aluminium oxide

Hence, the number of moles of produced will be 0.52 moles.

it's all four options.