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Qualitative Analysis of Cations Name: Section Date: 2. Based on the student obse

ID: 1041278 • Letter: Q

Question

Qualitative Analysis of Cations Name: Section Date: 2. Based on the student observations, describe a procedure to: a) confirm the presence of Pb in a mixture of Pb and Cu ions. b) confirm the presence of Ni2 in a mixture of Pb and Ni" ions. 3. Would it be possible to confirm the presence of Cut or Ni2+ in a mixture of these two ions? Why or why not? 4. Consider the observations for the reaction of Pb ion with HCI. Explain how a studer could have an unknown mixture containing Pb and not be able to confirm it if t addition of reagents is not performed carefully.

Explanation / Answer

1. Add Cl2+, the lead chloride will precipitate to give a white solid.

2. Add sulphide ions, nickel will precipitate .

OR add NaOH. at first both lead and nickel produce a white precipitate so add NH3 after the NaOH. this will make the nickel react with the solution and dissolve the precipitate producing a violet solution.

3.Cu2+ is coloured . So it is possible to recognise it's presence in the mixture .