when 2.50g of copper reacts with oxygen, the copper oxide product has a mass of 2.81g what is the simplest of?

Answer 1

Since you didn't' finish your question I can only guess that you want the simplest formula. Copper has an atomic mass of 63.55 g and oxygen has an atomic mass of 15.99 g. With 2.50 g of copper there is 0.31 g of oxygen (2.81-2.50=0.31). The moles of copper are determined by dividing the number of grams by the atomic mass: 2.50 g/63.55 g/mole=0.039 moles. Likewise for oxygen: 0.31/15.99=0.019. Divide both answers by the smaller number (0.019) to get the relative proportions: 2 copper atoms to 1 oxygen atom. Copper can have a valence of +1 or +2 while oxygen has a valence of -2. Choosing the +1 valence of copper the empirical formula of the compound becomes Cu2O. I believe this mineral is called cuprite, although it has been a time since I have seen cuprite's formula.

Answer 2

Convert both.50 grams of copper into moles using the atomic mass of Cu. contained in the oxide, you've 0.31 grams of oxygen, precise? Convert that to moles by technique of dividing by technique of the atomic mass of O. From those 2 numbers of moles, you have to be in a position to make certain out the formula of the compound.