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

c is having 4 valence electrons and is bonded to three hydrogens and one sulphur atom, therefore, the number of bond pair is equal to four. as all the valence electrons are used in forming the bonds so, there is no lone pair left on carbon.

s is having 6 valence electrons and is bonded to one other sulfur atom and one carbon atom, therefore, the number of bond pair is equal to 2. as only two valence electrons are used in forming the bonds so, four electrons are left. therefore, two lone pairs are present on s.

answerlinnaeus;