What mass of aluminum is produced by the decomposition of 5.0 kg A l 2O 3? How many moles of oxygen are produced?

mass of Aluminum produced = = 2.647 kg

moles of Oxygen = 73.53 moles

Given

5.0 kg Al₂O₃

Required

moles of Oxygen

Solution

The aluminum oxide gets decompose into aluminum and oxygen gas.

Reaction :

2Al₂O₃(s)⇒ 4 Al(s) + 3O₂(g)

mol of Al₂O₃(MW=102 g/mol) :

= mass : MW

= 5000 g : 102 g/mol

= 49.02 moles

From the equation, mol ratio of Al₂O₃ : O₂ = 2 : 3, sol mol O₂ :

= 3/2 x mol Al₂O₃

= 3/2 x 49.02

= 73.53 moles

mol Al :

= 4/2 x mol Al₂O₃

= 2 x 49.02

= 98.04 moles

Mass Al :

= mol x Ar Al

= 98.04 x 27 g/mol

= 2647.08 g

= 2.647 kg