Question

Indicate whether the erroro introduced by each of the following problems would result in a high or low value for Cu recovery, or would not affect the results? c. some of the copper nitrate solution is splashed out of the beaker in part 1. B. Insufficent NaOH is added in Part 2 B. the solutions bumps, in Part 3, splashing out some Cuo B. some solid is lost in the decanting process would not affect the recovery of Cu B. low value for Cu recovery A adding excess H2SO4 in part 4 C some unreacted zinc remains with the product at the end of the exerpiment c, high value for Cu recovery the washings in part 5 are insufficent to remove all of the solution residues from copper C. c. the copper is not completely dried

Answer 1

The reactions that involve in the above experiment :

1) Cu(NO3)2 + NaOH ---> Cu(OH)2 (s) + NaNO3(aq)

2) Cu(OH)2 (s) -----> CuO(s) + H2O(aq)

3) CuO(s) + H2SO4(aq) -----> CuSO4(aq) + H2O(aq)

4) CuSO4(aq) + Zn(s) ----> ZnSO4(aq) + Cu(s)

a) When some of the copper nitrate solution is splashed out of the beaker - As some of Cu(NO3)2 is lost then final amount of copper will also be less. Hence low value of Cu recovery

b) Insufficient NaOH is added - When insufficient NaOH is added then extraction of Copper hydroxide will be less. Hence low value of Cu recovery

c) Splashing out of CuO - As CuO splashes out then its amount will be less which results in less yield of Cu. Hence low value of Cu recovery

d) Some solid is lost in decanting process - when solid copper salt product is lost then there will be less yield of Cu. Hence low value of Cu recovery

e) Adding excess H2SO4 - Eventhough excess sulphuric acid is added the amount of sulphuric acid that is required will involve in the reaction remaining will be left in the solution. Hence no effect on Cu recovery

f) Some unreacted zinc remains with the product - As zinc is left with the product then the weight of final product increases. Hence show high value of Cu recovery

g) the washings are insufficient to remove all the solution residues from copper - As washings are insufficient to remove all the solution residues from copper. This shows that residues remains with the copper that result in the increase in the weight of final product. Hence show high value of Cu recovery

h) Copper is not completely dried - as it is not completely dried, it remains wet. This wetty copper product result in the increase in the weight of final product. Hence show high value of Cu recovery