Page 82 - Chemistry - XI

Q52. Why is lead indicated in both groups I and II qualitative analysis?
Ans. It is because Pb get precipitated as PbCl in group I and PbS in group II.
2+
2

COMPETENCY BASED QUESTIONS

Multiple Choice Questions
Q1. Addition of aqueous sodium hydroxide to a solution of an unknown metal ion forms a green
precipitate. The precipitate turns reddish brown upon standing. Which of the following
could be the metal ion present in the solution?

(a) Cu (b) Fe (c) Mg (d) Al 3+
2+
2+
2+
Q2. Which of the following can be used for testing SO in given salt?
2−
4
(a) HNO (b) Ba (NO ) (c) NH OH (d) NaOH
3
4
3 2
Q3. Which of the following ions will give a coloured precipitate with excess of NH OH ?
4
(a) Cu (b) Fe (c) Ca (d) Ba 2+
2+
2+
2+
Q4. Which of the following ions will not give precipitate with NH OH ?
4
(a) Zn (b) Cu (c) Ca (d) Al 3+
2+
2+
2+
Q5. Ammonium hydroxide solution when added to solution of ʻAʼ gives white precipitate which is
insoluble in excess of NH OH solution. Cation in ʻXʼ is:
4
(a) Al (b) Cu (c) Zn (d) Ca 2+
3+
2+
2+
Q6. The salt which is formed when conc. sulphuric acid reacts with KNO above 2000°C is:
3
(a) K SO (b) K SO (c) KHSO (d) KHSO 3
3
4
4
2
2
Q7. The indicator which changes to pink colour in alkaline solution is:
(a) Blue litmus (b) Methyl orange (c) Red litmus (d) Phenolphthalein
Q8. Which of the following is not black ppt?
(a) CuS (b) NiS (c) CoS (d) ZnS

Q9. Which of the following forms chocolate coloured ppt with KFeCN ?
6
4
(a) Zn (b) Cu (c) Mg (d) Ni 2+
2+
2+
2+
Q10. The nitrate which on thermal decomposition leaves behind a residue which is yellow when hot
and white when cold:
(a) Lead nitrate (b) Ammonium nitrate
(c) Copper nitrate (d) Zinc nitrate
Q11. The white ppt formed when Mg reacts with aqueous solution of Na HPO in presence of
2+
2
4
NH Cl, NH CH is due to:
4
4
(a) MgSO (b) Mg(NH )PO (c) Mg (PO ) (d) All of these
4 4 4 3 4 2
Q12. When MnO is heated with conc. HCl, a yellow green gas is given off . The gas turns moist blue
2
litmus paper red before bleaching it. The identity of the gas and role of MnO respectively are:litmus paper red before bleaching it. The identity of the gas and role of MnO
2
(a) Cl , reducing agent (a) Cl 2 (b) Cl , oxidising agent
2
(c) HCl, reducing agent
(d) HCl, oxidising agent
(c) HCl, reducing agent (d) HCl, oxidising agent
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