Chemistry

posted by .

Ik this has been answered, but doesn't the copper oxide have something to do with it? And could you explain it in simpler terms? I'm just confused because you said forget the copper oxide, but your using it somehow, what puzzles me is the carbon dioxide, because the copper oxide plus the carbon make the copper, but also the carbon dioxide. Could you explain it simpler and explain how you got that answer (simpler)


Copper Oxide + Carbon -> Copper + Carbon Dioxide

Calculate the mass of carbon needed to obtain 63.5g of copper from 79.5g of Copper Oxide

  • Chemistry -

    balance the equation

    2CuO+C>>2Cu + CO2

    each mole of carbon yields 2mmoles Cu

    how many moles of Copper is 63.5 grams?
    answer: 63.5/63.5=1mole
    so you need half that number of moles of Carbon, or .5 moles of carbon, or six grams.

  • Chemistry -

    2CuO + C ==> 2Cu + CO2
    1. I ignored the CuO because the problem states you want 63.5 g Cu. How many mols Cu is that? mols Cu = grams/atomic mass = 63.5/63.5 = 1 mol Cu is what you want.
    2. If it comes from the equation above then 2 mols Cu is obtained for every mol C or 1/2 mol C for 1 mol Cu. So 1 mol Cu I will get from 1/2 mol C.
    3. Since g = mols x atomic mass, then g C = mols C x atomic mass C = 0.5 x 12 = 6 grams C.
    4. Note I didn't use CuO anywhere except in the equation. If it follows all of the laws of chemistry, knowing Cu I want will tell me how much CuO I need, how much C I need, and how much CO2 will be produced. But the problem didn't ask anything about CO2, or CuO so I didn't use them anywhere.
    5. There COULD be a complicating factor IF (and only IF) the CuO would not give the amount of Cu you want in the problem BUT 1 mol CuO is 63.5 + 16 = 79.5; however, in that case I would have pointed out that it couldn't be done; i.e., 60 g CuO for example could not produce 63.5 g Cu so we were spinning our wheels.

    To work a simple stoichiometry problem (as opposed to a limiting reagent problem) you need four steps.
    1. Write and balance the equation.
    2. Convert grams of what you have to mols. mols = grams/atomic mass in this case or grams/molar mass in the case of molecules. That's the 63.5/63.5 = 1 mol Cu step above.
    3. Using the coefficients in the balanced equation, convert mols of what you have (in this case mols Cu) to mols of what you want (in this case C). That's the 1 mol Cu x (1 mol C/2 mols Cu) = 1 x 1/2 = 0.5 mols C
    4. Then convert mols of what you want (the C) to grams. g = mols x atomic mass = 0.5 x 12 = 6.

    These four steps will take care of any non-limiting reagent problem you have.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Chemistry

    Copper dissolves in nitric acid, producing copper (ll) nitrate. After reaction with sodium hydroxide and heating, copper nitrate changes to copper (ll) oxide. Calculate the percent yield of this process if 1.235 g of copper produced …
  2. Chemistry

    ammonia gas reacts with copper (ii) oxide at high temperatures to produce elemental nitrogen, copper metal, and water vapor. Assume that 36.2g ammonia reacts with 180.8 g copper ii oxide. (balanced equation: 2 NH4 (ammonium) (g) + …
  3. chemistry

    When copper(II) oxide is heated in the presence of hydrogen gas, elemental copper and water are produced. What mass of copper can be obtained if 22.8 g copper(II) oxide is used?
  4. chemistry

    there are 2 reactants copper(II) oxide and hydrochloric acid the products are copper(II)chloride and water. what change will you observe in the copper(II)oxide?
  5. Chemistry

    When copper(II) oxide is heated in the presence of hydrogen gas, elemental copper and water are produced. What mass of copper can be obtained if 34.0 g copper(II) oxide is used?
  6. chemistry

    There are two different oxides of copper produced as a result of this reaction. They are copper(I) and copper(II) oxide. If copper is changed to copper(I) oxide the percentage changed in mass is 12%. If copper is changed to copper(II) …
  7. chemistry

    One of the reactions involved in the smelting of copper sulfide ores involves copper(I) oxide and copper (I) sulfide: 2Cu2O(solid) + Cu2S(solid) ---> 6Cu(solid) + SO2(gas) Assuming that 35.00 g of copper (I) oxide is heated with …
  8. chemistry. please help drbob222

    One of the reactions involved in the smelting of copper sulfide ores involves copper (I) oxide and copper (I) sulfide: 2Cu2O2 + Cu2S ---> 6Cu + SO2 Assuming that 35.00 g of copper (I) oxide is heated with 25.00 g of copper (I) sulfide …
  9. Chemistry

    is it easy to distinguish between between the different oxidation states of copper?
  10. Chemistry

    You synthesized copper (I) chloride and copper (I) oxide. How do they differ from their copper (II) analogs?

More Similar Questions