1.

A chemist opened a cupboard and found four bottles containing water solutions, each of which had lost its label.Bottles 1,2,3 contanied colourless solution, while bottle 4 contained a blue solution.The labels from the bottles were lying scattered on the floor of the cupboard.They were: copper (II) sulphate, Hydrochloric acid lead nitrate , Sodium carbonate By mixing samples of the contents of the bottles, in pairs , the chemist made the following observations : Bottle 1 +Bottle 2 to White precipitate is formed. Bottle 1 +Bottle 3 to White precipitate is formed. Bottle 1 +Bottle 4 to White precipitate is formed. Bottle 2 +Bottle 3 to Colourless and odourless gas is evolved. Bottle 2 +Bottle 4 to No visible reaction is observed. Bottle 3 +Bottle 4 to Blue precipitate is formed. With the help of the above observations answer the following questions. Which of the following statements is correct for salts contained in bottle 1 and 4 ?

Answer»

Bottle 4 gives white PRECIPITATE with EXCESS of KI solution
Bottle 4 gives white precipitate with excess of `K_4 [Fe (CN)_6]` solution
Bottle 1 and 4 both gives precipitate with excess of NaOH solution
Bottle 1 gives white precipitate with concentrated HCl solution

Solution :(A)`2Cu^(2+)+4I^(-)toCu_2I_2 darr ("white")+I_2`
(B)`2Cu^(2+)+[Fe(CN)_6]^(4-)toCu_2[Fe(CN)_6]darr` (chocolate brown)
(C )`Pb^(2+)+4OH^(-)to[Pb(OH)_4]^(2-)`(colourless soluble complex) , `Cu^(2+)+2OH^(-)TOCU(OH)_2darr`(blue)
(D)`Pb^(2+)+4Cl^(-)to[PbCl_4]^(2-)darr` (colourless soluble complex)


Discussion

No Comment Found

Related InterviewSolutions