inorganic 2

ITEM	CONTENT	MARKS
Objective	The purpose of this experiment is to perform qualitative analysis to identify transition metal cations
Introduction	Qualitative analysis is the determination of the types of ions present in a solution.Confirmatory tests are to determine conclusively that a certain ion is present.Intefering ions is removed before proceed with the cofirmatory test.         In this experiment we are using mixture that is provided by lab assistant.First we are separating the ion in the mixture by using HCl solution.          After they have been separated , the identification of each transition metal cation depends of the observation of a characteristics chemical reaction.From the characteristics we can determine what kind of metal ion present in the mixture.
Results	1) On adding HCl to the mixture sample Observation Cloudy blue solution formed Balanced chemical equation Cu2+(aq) + H2S(aq)                CuS(s) + H2O(lq) Supernatant is formed 2) On adding H2S Obsevation Brownish precipitate with cloudy solution formed Precipitate and supernatant was formed, so we that there is present Cu2+ and Zn2+ in the mixture. Balanced chemical equation Cu2+(aq) + S2-(aq)                CuS(S) RESULT FOR CONFIRMATORY TEST FOR Cu2+ a)On adding  HNO3 Observation Black precipitate was formed Balanced chemical equation 3CuS(S)+8H+(aq)+2NO3-(aq)           3Cu2+(aq)+2NO+(aq)+3S(S)+4H2O(lq) b)On adding NH3,HNO3,and K4Fe(CN)6 Observation Brown precipitate was formed Balance chemical equation 2Cu2+(aq) + Fe(CN)64-(aq)           Cu2[Fe(CN)6](S) Therefore presence of Cu2+ was confirmed. RESULT FOR COFIRMATORY TEST FOR Zn2+ a)On adding HCl , NH3  and thioacetamide Observation Black precipitate was formed Balance chemical equation Zn2+(aq)+s2-(aq)          ZnS(s) b)On adding NH3,CH3COOH AND K4Fe(CN)6 Observation Brick red precipitate was formed Balance chemical equation 3Zn2+(aq) + 2Fe(CN)64-(aq)        Zn3[Fe(CN)6]2(s) Therefore presence on Zn2+ was confirmed.
Discussion	This experiment involving the qualitatives analysis which contain one or more metal cations.Several specific reactions will be carried out on solutions that will either separate the ions from each other to confirm the presence of particular ion.The reactions that confirm the presence of a particular ion involve the creation of visible product such as precipitates or coloured species .The reaction that involves the precipitation also be applied in the reaction.Qualitatative analysis rection is simple reaction because we identify only one ion for each time.         For the first experiment , HCl was used to precipitate Cu2+ as while as precipitate as CuS.This can be shown by balance chemical equation : Cu2+(aq) + H2S(aq)                CuS(s) + H2O(lq) From the observation supernatant was formed.After that we add H2S and the observation is brownish precipitate with cloudy solution formed. From the observation we know that supernatant and black precipitate was formed.So we separate the supernatant and the precipitate into different test tube.        Now we are discussing about the confimatory presence of Cu2+ first.The brownish precipitate was formed in this reaction can be showned by the balance equation below : Cu2+(aq) + S2-(aq)                CuS(S)          After that we add HNO3 into the soluition and boil several minutes to make sure the reaction was completed.The black precipitate was formed.This reaction can be showned by the equation below: 3CuS(S)+8H+(aq)+2NO3-(aq)  3Cu2+(aq)+2NO+(aq)+3S(S)+4H2O(lq)       After we centrifudge the solution , the precipitate was discarded.6 M NH3,6M HNO3 and K4Fe(CN)6 was added.Brick red precipitate was formed.This reaction can be showned by the chemical equation below : 2Cu2+(aq) + Fe(CN)64-(aq)           Cu2[Fe(CN)6](S) There from the equation and observation , the presence of Cu2+ was confirmed.       Now we are discussing about the presence of Zn2+.After adding HCl , NH3 and thioacetamide black precipitate was formed.The chemical reaction can be showned as below: Zn2+(aq)+s2-(aq)          ZnS(s) After we add with another one drop of HNO3 black precipitate was formed.Next we are adding NH3 , CH3COOH and K4Fe(CN)6 , brick red preciptate was formed.This can be showned by the balanced chemical equation below :  3Zn2+(aq) + 2Fe(CN)64-(aq)        Zn3[Fe(CN)6]2(s)        There is some precaution that we should be aware.First makesure that our test tube that we are going to use is very clean and do not touch the tip of any dropper to any other test or other solution , it is because it may cause contamination.  We know that many chemical in the laboratory are toxic , we should wearing gloves for handling it and be careful not spill at our skin and do not smell the chemicals . This chemical may harmed us .
Conclusion	As we know qualitative analysis involves the identification of the substances in a mixture ,  so the qualitative analysis was performed.From the experiment above the mixture containing Cu2+ ion and Zn2+ ion.
References	1)