Between Lab Period 1 and Lab Period 2, design a separation scheme for all 4 cations. Use the results of your preliminary tests and the reasoning illustrated in the introduction and the Week 2 Worksheet. Be sure to include equations for all the reactions which occur at each step in the scheme. Record the scheme in the data section of the lab notebook. The scheme MUST be submitted at the start of Lab Period 2. It will be reviewed by the TA at the start of the lab period, before you begin testing your scheme. Ag+, Fe 3+ Cu2+, Ni2+

                    SEPARATION SCHEME FOR  CATIONS

GIVEN  CATIONS :

    Step 1:   Add of to the mixture solution

    Result : This would cause a precipitate of to be formed

    Reaction :  

    Step 2 : Next is to remove the precipitate and add to the remaining          

                 solution in the presence of of HCl

     Result : This would cause a precipitate of to be formed

     Reaction :  

     Step 3: Next remove the precipitate then add of aqueous      

                  , process the solution in a centrifuge,when the  

                 process  is done then sort out the  precipitate from the  solution

                 Now this precipitate is   and the remaining solution

                contains  

                 Next take out the precipitate to a different beaker and add HCl

                to it   this will dissolve it, then add a drop of this will

                form  a precipitate   which will have the color of

                 blood  indicating the presence of

   Reaction :  

                      Now the remaining mixture contains

Explanation:

assuming that your periodic table has eighteen columns, you should highlight   the four elements in the third column from the left of the table.

neutral atoms of elements after calcium contain d electrons. the energy of d orbitals of a particular main shell lies between the energy of the s and p orbitals of the next main shell. for example, electrons in the have energy higher than those in the orbital while lower than those of the orbital.

by the aufbau principle, electrons fill orbitals one at a time, starting from those of the lowest energy. the orbital is therefore filled right after orbitals and before orbitals.  

potassium has electron configuration and calcium . the s orbital of a main shell holds a maximum of two electrons. the next element would thus have the electron configuration and satisfy the requirements.

a neutral atom of the element contains three electrons on top of the most recent noble gas element. it should thus be placed in the third column of the periodic table. both scandium and yttrium would satisfy the conditions. an aufbau diagram indicates that the 4f orbital is filled before the 5d. however, it appears that exceptions exists for both lanthanum and actinium. neutral atoms of the two d-block elements also demonstrate the and should be highlighted as well.