An Unknown Compound

[haengbon]

1. The problem statement, all variables and given/known data

A compound containing element A and oxygen has a mole ratio of A:O = 2:3. If 8.0 grams of the oxide contains 2.4 grams of oxygen...

a) what is the atomic weight of A?
b) what is the weight of one mole of the oxide?
c) what is the theoretical weight of the oxide formed when 28 g of A is heated in excess oxygen?
d) what is the % yield if 38 grams was produced from 28 grams of A?

2. Relevant equations

....

3. The attempt at a solution

I didn't have any because I barely understood what to do :( can someone please guide me on how to solve this? It'll be of great help ^^

[symbolipoint]

Start with the oxygen. How many moles of oxygen is equivalent to that 2.4 grams of oxygen from the compound?

[haengbon]

so I'll convert the oxygen grams to moles right? :)

[Borek]

Yes. Then try to find out how many moles of the oxide you have (look at the formula).

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