Lab_3 - ____________________________...

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Unformatted text preview: ____________________________ ____________________________ ____________________________ ____________________________ ____________________________ ________________ ____________________________ ____________________________ ____________________________ ____________________________ ____________________________ Identification of the Basic Radicals of groups 1, 2 and 3 1, ________________ ____________________________ As we said before that, As ____________________________ Any Salt must consists of two radicals, one of them is the Acidic Radical and the Other is the Basic Radical. ____________________________ ____________________________ ____________________________ ________________ So to identify the salt, we must know the two radicals. two 1 ____________________________ In the identification of the Basic Radicals, we must make two tests, ____________________________ 1- Principal Test: which identify the group. Principal which ____________________________ 2- Confirmatory Test: which confirm the Confirmatory presence of the Radicals. presence ____________________________ ____________________________ ________________ ____________________________ ____________________________ ____________________________ ____________________________ ____________________________ ________________ ____________________________ ____________________________ ____________________________ ____________________________ ____________________________ Both test are carried out on the salt Both solution and we seek for formation of ppt. solution So before beginning identifying the basic So Radicals we must prepare a solution of the salt. How? •To prepare salt solution: We Put a small amount of the solid salt in We the test tube and then add a considerable volume of water and shake the tube very well till the salt disappear. All the Basic Radicals are classified into Six groups, each group has its own reagent which give a reaction only with the basic radicals of this group only not with the other groups (Principal Test). (Principal ________________ 2 Group Principal Test Principal ____________________________ Group I Soln + dil HCl dil ____________________________ dil Group II Soln + dil HCl + H2S ____________________________ NH Group III Soln + NH4Cl + NH4OH Group ____________________________ NH Group IV Soln + NH4Cl + NH4OH + H2S ____________________________ ________________ ____________________________ Soln + NH4Cl + NH4OH + NH (NH4)2CO3 (NH Has no general Reagent but every Has Group VI radical has its own reagent. radical Group V Basic Radicals Group One ____________________________ Salt Soln + dil HCl Salt Soln dil ____________________________ ____________________________ ____________________________ ________________ White PPT. Note: ____________________________ ____________________________ ____________________________ ____________________________ ____________________________ ________________ The Reagent of the first group of The Acidic and Basic radical is the same which is dil HCl dil But their observations are different. In the Acidic Radicals, We seek for We Effervescence or Gas Evolution. Effervescence While in the Basic Radicals, We seek We for ppt Formation. ppt 3 ____________________________ We have Three Basic Radicals in this group which are this ____________________________ ____________________________ ____________________________ ____________________________ ________________ ____________________________ ____________________________ Ag+ Silver Hg+ Mercurous Pb+2 Lead To differentiate between Pb+2 and and Ag+ Ag White ppt White ppt ____________________________ ____________________________ Pb+2 No ppt No ppt ____________________________ Ag+ Soln + dil H2SO4 dil ________________ ____________________________ Confirmatory Test of Pb+2 ____________________________ • Salt Soln + NaOH gives White ppt. Salt Soln NaOH gives ppt ____________________________ ____________________________ ____________________________ Confirmatory Test of Ag+ • Salt Soln + NaOH gives Brown ppt. Salt Soln NaOH gives ppt ________________ 4 ____________________________ ____________________________ ____________________________ ____________________________ ____________________________ If there is no ppt formed, then we must ppt formed, make the Principal Test for the second group. group. We have four Basic Radicals in this We group which are: group Cu+2 Bi+3 Bismuth ________________ Hg+2 Mercuric Cd+2 Cadmium Cupper Group Two ____________________________ ____________________________ Salt Soln + dil HCl + H2S Salt Soln dil ____________________________ ____________________________ ____________________________ ________________ Black PPt Black PPt Yellow PPt Yellow PPt Hg+2 Brownish Black Brownish PPt PPt Black PPt Black PPt Cu+2 Bi+3 Cd+2 ____________________________ So if Yellow ppt is formed, then we have So ppt is only one choice which is Cd+2. and we only and must make the confirmatory test for Cd+2 which is: Cd ____________________________ Salt Soln + NaOH gives White ppt. Salt Soln NaOH gives ppt ____________________________ ____________________________ ____________________________ ________________ Or Salt Soln + Potassium ferrocyanide Salt Soln Potassium ferrocyanide gives White ppt. gives ppt 5 ____________________________ ____________________________ If Black ppt is formed, then we have ppt is +2, Cu+2 or Bi+3 so we make a either Hg either so test to differentiate between them. ____________________________ Yellow ppt Yellow ppt Hg+2 Blue ppt Blue ppt Cu+2 White ppt White ppt Bi+3 ____________________________ ____________________________ Soln + NaOH Soln NaOH ________________ ____________________________ ____________________________ ____________________________ Confirmatory Test of Hg+2 • Salt Soln + KI gives Red ppt. Salt Soln KI ppt Confirmatory Test of Cu+2 ____________________________ • Salt Soln + Potassium ferrocyanide gives Salt Soln Potassium ferrocyanide gives Reddish Brown ppt. ppt ________________ Confirmatory Test of Bi+3 ____________________________ • Salt Soln + KI gives dark Brown ppt. Salt Soln gives ppt Group 3 ____________________________ ____________________________ Salt Soln + NH4Cl + NH4OH Salt Soln NH ____________________________ ____________________________ ____________________________ ________________ Gelatinous White ppt ppt Green PPt Green PPt Al+3 Cr+3 6 Reddish Reddish Brown ppt ppt Fe+3 Confirmatory Test of Al+3 Confirmatory ____________________________ ____________________________ ____________________________ ____________________________ ____________________________ ________________ ____________________________ • Salt Soln + Na2HPO4 gives White ppt. Salt Soln gives ppt Confirmatory Test of Cr+3 • Salt Soln + Na2HPO4 gives Green ppt. Salt Soln gives ppt Confirmatory Test of Bi+3 • Salt Soln + Potassium ferrocyanide gives Salt Soln Potassium ferrocyanide gives Deep Blue ppt. ppt Name: Bench Number: Date: /10/2006 Exp. ____________________________ ____________________________ 1- ____________________________ 2- ____________________________ 3- ________________ 45- ____________________________ ____________________________ ____________________________ ____________________________ ____________________________ ________________ 7 Section: Program: Obs. Res. ...
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