How many liters of oxygen are needed to react completely with 81.0 g of aluminum at STP? A.) 25.2 L
B.) 72.0L
C.) 50.4 L
D.) 67.2 L

Volume O₂ at STP = 50.4 Liters

Explanation:

4Al(s) + 3O₂(g) => 2Al₂O₃(s) at STP conditions

81g Al(s) = 81g/27g/mole = 3mole Al

moles O₂ consumed = 4/3(3)moles O₂ = 2.25 moles O₂ consumed

Volume O₂ at STP = 2.25moles x 22.4L/mole = 50.4 Liters O₂

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

that's it!

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