To determine how many moles of N₂O₃ contain 1.20 moles of oxygen, we first need to look at the chemical formula of nitrogen trioxide (N₂O₃).
In one mole of N₂O₃, there are 3 moles of oxygen atoms. This means that for every mole of N₂O₃, you get 3 moles of O. To find out how many moles of N₂O₃ are needed to get 1.20 moles of O, we can set up the following ratio:
Let x be the number of moles of N₂O₃. According to the proportion, we have:
x moles of N₂O₃ = 3x moles of O
If we know that we want 1.20 moles of O, we can set up the equation:
3x = 1.20
Solve for x:
x = 1.20 / 3
x = 0.40
Thus, to contain 1.20 moles of oxygen, you need 0.40 moles of N₂O₃.