Question

5. To confirm cobalt ion, nitrite ion is added. a. What is seen if nitrite is present? b. What is the chemical formula of this substance? c. What is the name of this substance? 6. The filtrate containing Fet. Mn?, AP, Crand Zn? is heated with 6M HNO3. a. What is the purpose of this process? Give a chemical equation that describes the reaction and explain why this is advantageous for the separation. b. The acid mixture is boiled to a residue and 6 M hydroxide ion and H.O, is added. This strongly basic solution allows the above ions to be separated into two groups. Explain these groups, writing out the specific formula of each compound and explaining which group it will be in. 7. The precipitate from the above separation is acidified. a. What cations could be present in the solution? b. One part of this solution is mixed with crystals of NH.SCN, and a dark red color is seen. What is the formula of this dark red ion? c. What would be the name of this cation?

Answer 1

Ansi ya 5.a) on presence oto nitrite ion (voz) the Cobalt ion will undergo coordinalion complex formation and we have sean that a yellow coloured cobalt complex is found. 3-7 . b) Chemical formula of the coordination compound formed - [CO(NO2),]*** c) Name of the coordination substance formed Cowallinitrite ion D 6.a) A filtrate containing fee must als" Cristaind 342+ is heated with 6M HNDZONE Purpose! Boiling or heating with HNDZ facilitates the removal o interfering acid radicals like phosphate, borata Silicate ele because during the precipitalion of the above cons as hydroxides (by adding WHY OH in presence of NHIAL) the interfering acid radicals of Gr. II and Mg2+ ions will also gets precipitated along with the above ions hydoonides Also, HNoz helps to oxidise Fe2+ ion to Festion so that the incomplete precipitation of Fe (OH)2 by NHL OH can be avoided. Chemical Reaction! Oxidation Feftcaq) + Conc. HNOz - feb (aq) [6m) A Present Prussian Blue A l ml sotulion Ki [Fe(CN) 67

6.6) when the acid mixture is boiled with strongly alkaline medies the above all ions are separated into 2 Aroups. (Gr. III A L I (Gr. IIB felon), - Brown Residue | Mnogi 2490 - Flesh coloureo Residue Naz crou - Yellow filtralē Na, 2002. – Colourless Na AL02 - Colourless filtralé l Fittrate 7:a) The first Slotained precipitate of the above separation when acidified the solution will contain Festion because, the fecoh), is the residue, so obtained first in this separation de la o to laterali 27 b) When one part of the above solution is nüned with the crystals of NHysen a dark red coloured coordination compowerd is formed. Fe3+ + NH4 SeN ->[fe(scn) ] # authat Th Blood Red og Dark Red Coloured - Complex The name of the above cation is Felsen)2+ iron thiocyanate dipositive ion-