SCH4C  Qualitative Analysis - Group 5 Analysis Separation Table
                                            The Alkaline Metals Group
To the final filtrate from the Group Separation table.
Part 1:
Add NH4OH until the solution is basic to litmus.  Add KH2PO4 solution drop by drop.  A white precipitate of MgNH4PO4 confirms the presence of the Mg2+ ion.

(reaction #32)

Part 2:  
Evaporate to dryness.  Add dilute HNO3, evaporate again.
Once the evaporating dish is cool, add 2 mL of distilled water and divide evenly into 2 parts.
Part 1:
Add 2 mL of magnesium uranyl acetate. Cool the solution.  Scrap the walls of the test tube to help crystallization.
Very pale yellow crystals confirms the presence of Na1+.

(reaction #33)
 

Part 2:
Add 2 mL of HCl and 2 mL of sodium cobaltinitrite solution.  

Warm, then cool quickly.

Scrap the walls to help precipitation.   A pale yellowish-brown precipitate confirms the presence of the K1+ ion.

(reaction #34)


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Copyright 1997, 2002, 2003  Tom Stretton (stretton@ripnet.com) Updated August, 2002 ts.