What theoretical weight of the oxide is formed when 28 grams of A is heated in excess oxygen and what is the % yield if 38 grams of the oxide is...

The
reaction would be:

`2 A + 3 O -> A_2O_3`

 

Moles of O in the oxide:

`= (2.4 grams)/(16.0 (grams)/(mol e)) =
0.15 mol es`

Since the ratio is 2:3 then:

`2:3
and?:0.15`

`= 0.15 * 2/3 = 0.1...

href="https://en.wikipedia.org/wiki/Stoichiometry">https://en.wikipedia.org/wiki/Stoichiometry
href="https://en.wikipedia.org/wiki/Yield_(chemistry)">https://en.wikipedia.org/wiki/Yield_(chemistry)