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1) Copper metal (Cu) can be dissolved in nitric acid. The chemical equation for

ID: 811740 • Letter: 1

Question

1) Copper metal (Cu) can be dissolved in nitric acid. The chemical equation for the reaction which occurs is:

Cu + 4HNO3 -----> Cu(NO3)2  + 2NO3  + 2H2O

a) In order to produce 5.0 moles of NO2 ,_______ mole(s) of Cu must react with _____ mole(s) of HNO3 to produce ____ mole(s) of Cu(NO3)2 and mole(s) H2O.

b) If 938 g of Cu(NO3)2 are formed, then _____ g of copper and ______g of HNO3 are consumed. ________g of NO2 and ______ g of H2O are also formed.

2) In an actual experiment, 100.0 g each of copper and nitric acid are used and 70.0 g of copper (II) nitrate is obtained. In this experiment, the limiting reactant is ______ and the percentage yield of copper (II) nitrate is _____%.

Please fill in the blanks, show step-by-step calculations. Thank you for your time!

Explanation / Answer

1)

a) In order to produce 5.0 moles of NO2 ,_(5/2)______ mole(s) of Cu must react with __(10)___ mole(s) of HNO3 to produce _5/2___ mole(s) of Cu(NO3)2 and ________5__________mole(s) H2O.

Explanation:

Cu + 4HNO3 -----> Cu(NO3)2  + 2NO3  + 2H2O

1mole of Cu --------------------->4mole HNO3 --------------> 1mole of Cu(NO3)2 --------------> 2mole of NO2 --------------> 2mole H2O

1mole of Cu------------- 2mole of NO2

? mole of Cu------------- 5mole of NO2

Cu mole = 5/2

1mole of Cu --------------------->4mole HNO3

5/2 moles Cu-----------------------?

HNO3 moles = 10mloes

1mole of Cu -----------------1mole of Cu(NO3)2

5/2 moles Cu   = 5/2 mole of Cu(NO3)2

1mole of Cu ------------2 mole H2O

5/2 mole Cu --------?

moles of H2O =5

b) If 938 g of Cu(NO3)2 are formed, then _(318.5)____ g of copper and ___(1264.03)____g of HNO3 are consumed. __(461.47)______g of NO2 and __(180.57)____ g of H2O are also formed.

explanation

     Cu + 4HNO3 -----> Cu(NO3)2  + 2NO2 + 2H2O

     63.5g     252g                   187g         92g        36g

        ?                 ?                      938g ?    ?    

63.5g Cu -----------------187g Cu(NO3)2

?g Cu -----------------938g Cu(NO3)2

Cu = 318.5g

    

similarly we can calculated remaining species weight

2) limiting reagent is HNO3

% of yield of copper (II) nitrate = 70 x100/200

                                                  = 35%