Here is the 2nd Question with selected answers. Do share with us your thoughts on deriving to the answer.
2. Cu+ ions may be formed when
A) Cu 2+ ions are oxidised by Sulphur dioxide
B) Cu 2+ ions are reduced by copper
C) Cu is oxidised by nitric acid
D) Zinc is placed in copper sulphate solutionAns: B
Come students – time to learn as you think & practice!
A) is definitely out.
C) It should results in formation of Copper (II) Nitrate Salt and water. This
contains Cu2+ ions.
D) Displacement should results in formation of Cu2+ ions also.
As such B) should be the answer.
My thoughts. Correct me if i am wrong please. Thanks.
Reply
Consider:
A) Sulphur dioxide is a common reducing agent, and not an oxidizing agent.
Thus this is incorrect.
C) In GCE O Level (Grade 9/10), we learn that Cu (which is below H in the
reactivity series) does not react with dilute acid. As such, no reaction and this
cannot be the answer.
D) Displacement reaction yields Zn + CuSO4 => ZnSO4 + Cu.
Cu2+ has been reduced Cu (O oxidation state). Not the answer.
B) There is a possibility that Cu2+ being reduced to Cu+ by a Cu metal. One
electron is transferred in the process.
Reply