Question

Faxde Nood.a Name yune 2e, 209 : Date: Pre-lab Assignment: Anelysis of Group I1 Cations (Sn, Cd, Cu, B) Ate: The completed flow chart and the answers to the questions must be handed in to your lab instructor at the beginning of next week's lab period 1 (20 pts) Complete the flow chart below (note: ppt precipitate; Soln. solution) Sa, Cd, Cu, B pH-0.5, s pPt (color) 3M KOH ppt (color) Soln (color) 6M HC 6M HCL S oolr) ppt (color) Soln (color) 6M HNO, 6M NH, S Sola (color) 6M NH (color) Sls (olor) olor

Answer 1

Sn4, Cd2- Cu2-Bi3* wwwwye pH-0.5,S 2d Group reagent = hydrogen sulphide Precipitate color: yellow, Yellow, black, brown. Tinilsulphide Sns, Cadmium Sulphide Cds, Copper() Sulphide Cu S, Bismuth(I) Sulphide BiS зм кон Precipitate color: Yellow, black, Reminds the same.linert), Cadmium TinlWsulphide sns is an amphoteric brown. It Solution color: colorless or Sulphide Cds, CopperlII) Sulphide Cu S2, Bismuth(l) Sulphide BiS dissolves in both acid and base. white 25ns+5KOH K2SnOg+K2 S nS, +K2 5+3 H2 O 6м но 6 M HCL S On acidification, the sulphide is Tomake the medium agidic May contain sulphate or rEprecioitated KSnos+KSns+K:5+6HC ----> Solution color: white or colorless Solution color: Pale may contain sulphate or yellow chloride of Cu and Bi chloride of cadmium 25ns+5KC+H2o 6M NHs,5 6 M HNO Precipitate color: Yellow Solution color May contain nitrate of Copper colorless or white Cadmium react with H2S to form Cds and Bismuth 6M NH Precipitate color: Yellow Bismuth react with ammonia to Copper react with ammonia tp form BiOH) to form [CulNH)a] complex Precipitate color: white Solution color: deep blue