# Question #ba857

#### Explanation:

Lead will react with oxygen to produce lead oxide. There are two types of lead oxide and we need to know which one is produced.

First possibility :
$2 P b + {O}_{2} \rightarrow 2 P b O$

For every 2 moles of $P b$, we need 1 mole of ${O}_{2}$. So if we have .66 moles of $P b$, we need half that number of moles of ${O}_{2}$ in order to not have any $P b$ or ${O}_{2}$ left over. (This will also produce 2 moles of $P b {O}_{2}$)
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Second possibility :
$P b + {O}_{2} \rightarrow P b {O}_{2}$
For every 1 mole of $P b$, we need 1 mole of ${O}_{2}$. So if we have .66 moles of $P b$, we need the same number of moles of ${O}_{2}$ in order to not have any $P b$ or ${O}_{2}$ left over. (This will also produce 1 mole of $P b {O}_{2}$)