If 78.2 grams of oxygen react with copper, how many moles of copper oxide will be produced?  

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When copper reacts with oxygen, copper (II) oxide is formed. The reaction can be written as follows:

`Cu + O_2 -> CuO`

However, this reaction is not balanced, as the number of oxygen atoms are 2 on the reactant side, while there is only 1 oxygen atom on the product...

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When copper reacts with oxygen, copper (II) oxide is formed. The reaction can be written as follows:

`Cu + O_2 -> CuO`

However, this reaction is not balanced, as the number of oxygen atoms are 2 on the reactant side, while there is only 1 oxygen atom on the product side.

The well-balanced chemical reaction for this process can be written as:

`2Cu + O_2 -> 2CuO`

Using stoichiometry, we can see that 2 moles of copper react with 1 mole of oxygen to generate 2 moles of copper oxide. 

Here, we have 78.2 g of oxygen. The molar mass of oxygen is 32 g. Hence the number of moles of oxygen are: 

78.2 g / (32 g/mole) = 78.2/32 moles

Since 1 mole of oxygen produces 2 moles of copper oxide, the number of moles of copper oxide generated are:

(78.2/32)  x 2 moles = 4.89 moles of copper oxide.

Hope this helps. 

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