A mixture when rubbed with dilute acid smells like vinegar. It contains : 

(A) sulphite 

(B) nitrate 

(C) nitrite 

(D) acetate 

Which of the following is insoluble in dil.HNO₃ but dissolves in aquaregia? 

(A) HgS 

(B) PbS 

(C) Bi₂S₃ 

(D) CuS.

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

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^– 

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 S^2– 

(D) HCl lowers the solubility of H₂S in solution

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) 

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

Nitrates of all the metals are : 

(A) coloured 

(B) unstable 

(C) soluble in water 

(D) insoluble in water

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

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)