23 + Interview Questions in GENERAL QA IN SALT Page 1 InterviewSolution

1.	SO2 and CO2 both turn lime water (X) milky, SO2 also turns K2Cr2O7 /H+ (Y) green while O2 is soluble in pyrogallol (Z) turning it black. These gases are to be detected in order by using these reagents. The order is: (A) (X), (Y), (Z) (B) (Y), (Z), (X) (C) (Y), (X), (Z) (D) (X), (Z), (Y)
Answer» (C) (Y), (X), (Z)

Discussion

2.	Some white colourless crystals are heated. A cracking sound is heard and brown fumes are given off and the residue left is yellow-brown in colour. When a glowing splinter is held in the fumes, it is relighted. The fumes consist of : (A) O2 (B) NO2 (C) Cl2 (D) NO2 and O2
Answer» (D) NO₂ and O₂

Discussion

3.	A mixture of two colourless substance was dissolved in water. When gaseous Cl2 was passed through the solution, containing small quantity of CCl4 a violet colour developed in organic layer. Addition of BaCl2 to the original solution give a white precipitate. The mixture contains : (A) NaNO3 and AlCl3 (B) NaBr and KCl (C) MgI2 and MgSO4 (D) BaSO4 and PbCl2
Answer» (C) MgI₂ and MgSO₄

Discussion

4.	An aqueous solution of salt containing an acidic radical X – reacts with sodium hypochlorite in neutral medium. The gas evolved produces blue black colour spot on the starch paper. The anion X – is : (A) CH3COO – (B) Br – (C) I – (D) NO2–
Answer» The anion X ^– is I ^-.

Discussion

5.	To increase significantly the concentration of free Zn2+ ion in a solution of the complex ion [Zn(NH3)4] 2+ Zn2+ (aq) + 4NH3 (aq) ⇄ [Zn(NH3)4 ] 2+ (aq) add to the solution some : (A) H2O (B) HCl (aq) (C) NH3 (aq) (D) NH4Cl (aq)
Answer» Add to the solution some of HCl (aq).

Discussion

6.	White precipitate of AgCl turns to greyish or black when : (A) reacts with Na3AsO4 (B) expossed to sunlight (C) reacts with K2CrO4 (D) reacts with conc.HCl
Answer» (B) expossed to sunlight

Discussion

7.	Consider the following observation : Mn+ + HCl → white precipitate + Δ → water soluble. The metal ion Mn+ will be : (A) Hg2+ (B) Ag+ (C) Pb2+ (D) Sn2+
Answer» The metal ion Mⁿ⁺ will be Pb²⁺.

Discussion

8.	Which of the following statement (s) is/are true ? (A) Ag+ ions do not give white precipitate with concentrated HCl (B) Cu2+ ions produce a white precipitate when KCN solution is added in a small quantity (C) Hg2+ ions give deep blue precipitate with cobalt acetate and ammonium thiocyanate(D) Black precipitate of BiI3 turns orange when heated with water
Answer» All the options (A), (B), (C), (D) are correct.

Discussion

9.	H2S in the presence of HCl precipitates II group but not IV group because (A) HCl activates H2S (B) HCl increases concentration of Cl – (C) HCl decreases concentration of S2– (D) HCl lowers the solubility of H2S in solution
Answer» (C) HCl decreases concentration of S^2–

Discussion

10.	Cu2+ ions give white precipitate with : (A) excess KI solution (B) potassium thiocyanate solution (C) excess KCN solution (D) potassium hydroxide solution
Answer» (B) potassium thiocyanate solution

Discussion

11.	Fe(OH)3 and Cr(OH)3 precipitates are completely separated by : (A) Aq.NH3 (B) HCl (C) NaOH/H2O2 (D) H2SO4
Answer» (C) NaOH/H₂O₂

Discussion

12.	Nitrates of all the metals are : (A) coloured (B) unstable (C) soluble in water (D) insoluble in water
Answer» (C) soluble in water

Discussion

13.	In which of the pair the precipitates are red and black coloured respectively and both soluble in excess KI solution ? (A) HgI2, Hg2I2 (B) HgI2, BiI3 (C) Cu2I2, AgI (D) CdI2, PbI2
Answer» (B) HgI₂, BiI₃

Discussion

14.	When excess of dilute NH4OH is added to an aqueous solution of copper sulphate an intense blue colour is obtained. This is due to the formation of : (A) CuSO4 (B) Cu(OH)2 (C) [Cu(NH3)4 ]2+ (D) (NH4)2SO4
Answer» (C) [Cu(NH₃)₄ ]²⁺

Discussion

15.	Consider following reaction; Nitrite + Acetic acid + Thiourea → N2 ↑+ SCN – + 2H2O. Formation of the product in the above reaction can be identified by : (A) FeCl3 /dil.HCl when blood red colour appears (B) FeCl3/dil.HCl when blue colour appears (C) K2Cr2O7/HCl when green colour appear (D) KMnO4/HCl when colourless solution is formed
Answer» (A) FeCl₃ /dil .HCl when blood red colour appears

Discussion

16.	The addition of K2CO3 (aq) to the following solution is expected to produce a precipitate in every case but that one which does not produce precipitate is : (A) BaCl2 (aq) (B) CaBr2 (aq) (C) Na2SO4 (aq) (D) Pb(NO3)2 (aq)
Answer» (C) Na₂SO₄ (aq)

Discussion

17.	Nitrite (NO2– ) interferes in the ‘ring-test’ of nitrate (NO3– ). Some of the following reagents can be used for the removal of nitrite. I : NH4Cl (Solid) II : dil.H2SO4 III : NH2SO3 H (sulphamic acid) IV : Zinc /sodium hydroxide (A) I , II (B) I, II , IV (C) I , II , III (D) II , III , IV
Answer» (C) I , II , III

Discussion

18.	A mixture when rubbed with dilute acid smells like vinegar. It contains : (A) sulphite (B) nitrate (C) nitrite (D) acetate
Answer» It contains acetate.

Discussion

19.	Mg is not precipitated in V group because (A) MgCO3 is soluble in water (B) Ksp of MgCO3 is high (C) MgCO3 is soluble in NH4OH (D) None.
Answer» (B) Ksp of MgCO₃ is high

Discussion

20.	The solution of sodium meta aluminate on diluting with water and then boiling with ammonium chloride gives: (A) [Al(H2O)5OH]2+ (B) AlCl3 (C) Al (OH)3 (D) NaAl(OH)4
Answer» Ammonium chloride gives Al (OH)₃.

Discussion

21.	Which of the following is insoluble in dil.HNO3 but dissolves in aquaregia? (A) HgS (B) PbS (C) Bi2S3 (D) CuS.
Answer» But dissolves in aquaregia is HgS.

Discussion

22.	There are four test tubes containing dil. HCl, BaCl2, CdCl2 and KNO3 solutions. Which of the following will identify BaCl2 ? (A) KI (B) K2CrO4 (C) AgNO3 (D) both (B) and (C)
Answer» (D) both (B) and (C)

Discussion

23.	A suspension containing insoluble substance ZnS, MnS, HgS, Ag2S and FeS, is treated with 2N HCl. On filtering, the filtrate contains appreciable amounts of which one of the following? (A) zinc and mercury (B) silver and iron (C) manganese and mercury (D) zinc, manganese and iron
Answer» (D) zinc, manganese and iron

Discussion

Explore topic-wise InterviewSolutions in .

SO2 and CO2 both turn lime water (X) milky, SO2 also turns K2Cr2O7 /H+ (Y) green while O2 is soluble in pyrogallol (Z) turning it black. These gases are to be detected in order by using these reagents. The order is: (A) (X), (Y), (Z) (B) (Y), (Z), (X) (C) (Y), (X), (Z) (D) (X), (Z), (Y)

Some white colourless crystals are heated. A cracking sound is heard and brown fumes are given off and the residue left is yellow-brown in colour. When a glowing splinter is held in the fumes, it is relighted. The fumes consist of : (A) O2 (B) NO2 (C) Cl2 (D) NO2 and O2

An aqueous solution of salt containing an acidic radical X – reacts with sodium hypochlorite in neutral medium. The gas evolved produces blue black colour spot on the starch paper. The anion X – is : (A) CH3COO – (B) Br – (C) I – (D) NO2–

To increase significantly the concentration of free Zn2+ ion in a solution of the complex ion [Zn(NH3)4] 2+ Zn2+ (aq) + 4NH3 (aq) ⇄ [Zn(NH3)4 ] 2+ (aq) add to the solution some : (A) H2O (B) HCl (aq) (C) NH3 (aq) (D) NH4Cl (aq)

White precipitate of AgCl turns to greyish or black when : (A) reacts with Na3AsO4 (B) expossed to sunlight (C) reacts with K2CrO4 (D) reacts with conc.HCl

Consider the following observation : Mn+ + HCl → white precipitate + Δ → water soluble. The metal ion Mn+ will be : (A) Hg2+ (B) Ag+ (C) Pb2+ (D) Sn2+

H2S in the presence of HCl precipitates II group but not IV group because (A) HCl activates H2S (B) HCl increases concentration of Cl – (C) HCl decreases concentration of S2– (D) HCl lowers the solubility of H2S in solution

Cu2+ ions give white precipitate with : (A) excess KI solution (B) potassium thiocyanate solution (C) excess KCN solution (D) potassium hydroxide solution

Fe(OH)3 and Cr(OH)3 precipitates are completely separated by : (A) Aq.NH3 (B) HCl (C) NaOH/H2O2 (D) H2SO4

Nitrates of all the metals are : (A) coloured (B) unstable (C) soluble in water (D) insoluble in water

In which of the pair the precipitates are red and black coloured respectively and both soluble in excess KI solution ? (A) HgI2, Hg2I2 (B) HgI2, BiI3 (C) Cu2I2, AgI (D) CdI2, PbI2

When excess of dilute NH4OH is added to an aqueous solution of copper sulphate an intense blue colour is obtained. This is due to the formation of : (A) CuSO4 (B) Cu(OH)2 (C) [Cu(NH3)4 ]2+ (D) (NH4)2SO4

The addition of K2CO3 (aq) to the following solution is expected to produce a precipitate in every case but that one which does not produce precipitate is : (A) BaCl2 (aq) (B) CaBr2 (aq) (C) Na2SO4 (aq) (D) Pb(NO3)2 (aq)

Nitrite (NO2– ) interferes in the ‘ring-test’ of nitrate (NO3– ). Some of the following reagents can be used for the removal of nitrite. I : NH4Cl (Solid) II : dil.H2SO4 III : NH2SO3 H (sulphamic acid) IV : Zinc /sodium hydroxide (A) I , II (B) I, II , IV (C) I , II , III (D) II , III , IV

A mixture when rubbed with dilute acid smells like vinegar. It contains : (A) sulphite (B) nitrate (C) nitrite (D) acetate

Mg is not precipitated in V group because (A) MgCO3 is soluble in water (B) Ksp of MgCO3 is high (C) MgCO3 is soluble in NH4OH (D) None.

The solution of sodium meta aluminate on diluting with water and then boiling with ammonium chloride gives: (A) [Al(H2O)5OH]2+ (B) AlCl3 (C) Al (OH)3 (D) NaAl(OH)4

Which of the following is insoluble in dil.HNO3 but dissolves in aquaregia? (A) HgS (B) PbS (C) Bi2S3 (D) CuS.

There are four test tubes containing dil. HCl, BaCl2, CdCl2 and KNO3 solutions. Which of the following will identify BaCl2 ? (A) KI (B) K2CrO4 (C) AgNO3 (D) both (B) and (C)

A suspension containing insoluble substance ZnS, MnS, HgS, Ag2S and FeS, is treated with 2N HCl. On filtering, the filtrate contains appreciable amounts of which one of the following? (A) zinc and mercury (B) silver and iron (C) manganese and mercury (D) zinc, manganese and iron