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As Chemistry Mole ratio/Reacting ratio

1. I need help on how to find mole ratio for this equation for equation 1 because it has a half oxygen and i dont now the mole ratio for the whole eqution 1 because of that oxygen.

2. How to figure out which one is correct when measuring the volume of gas collected that will prove which one of the 2 eqautions are correct

This is all about mole ratio or reacting ratio.

Ok Cooper has 2 oxides, Cu2O and CuO

I have 0.65g of copper carbonate (CuCO3)(s) which decomposes on heating to form one of these 2 oxides above. There is only 1 equation that is correct. below for a possible reaction (this is the 2nd part im stuck on becuase i dont know how to work out which one is corect)


Equation 1: 2CuCO3(s) = Cu2O(S) + 2CO2(g) + 1/2 O2(g)

Equation 2: CuCO3(s) = CuO(s) + CO2(g)

Can somebody help me with this please becuase i cant find how to prove which eqautions are correct anywhere in my textbooks. I know how to work out the volume of gas and equation 2 but not for proving which eqution is correct and mole ratio for eqution 1.

Thank You
Reply 1
I'm not completely sure but for the equation ratio i would times throughout by 2 so that all of the moles are whole numbers the ratio can then be read off the equation
Reply 2
Equation 1 gives off oxygen? The second one doesn't? Can you prove this experimentally? You can also measure intial and final mass of copper oxides.
Reply 3
Since you know the amount of copper stuff that you are using, you can calculate how much CO2 and O2 would theoretically be produced by working out the moles of the copper stuff (mass = moles x mr)
Equation 1 is 4CuCo3 = 2Cu2O + 4CO2 + O2

Hence the moles of O2 = the moles of copper stuff / 4
The moles of CO2 = the moles of copper stuff

1 mole of any gas will occupy 24000cm cubed so times the number of moles of O2 by 24000 and the moles of CO2 by 24000 and add up the resulting volumes. If this doesn't equal the volume found in the experiment then the equation is incorrect.

Since you are heating then you may have to use the formula pv = nRT but you will need to know the pressure, moles and temperature to use this.

Hope this helps!
Reply 4
Sorry but i fogotten to tell you that this has not been done in a experiment its just a plan that i have to do and to work out which equation is correct by measuring the volume of gas that will prove one of the equations. Oh also im in as chmeistry year and that pvr formula is not in my sylabus so i dont know what that formula is about

Hope this helps
Reply 5
Obviously more gas forms in the second equation.

In equation one, 4 molecules of copper oxide gives 5 molecules of gas.

In equation two, 4 molecules of copper oxide only gives 4 molecules of gas.

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