JEE Advanced (Matrix Match & Integer Answer): General Principles & Processes of Isolation of Element | Chapter-wise Tests for JEE Main & Advanced PDF Download

Direction : question contains statements given in two columns, which have to be matched. The statements in Column-I are labelled A, B, C and D, while the statements in Column-II are labelled p, q, r, s and t.

Q.

Match the extraction processes listed in Column I with metals listed in Column II :          (2006 - 6M)

Ans: (A)- p, r; (B) - p, r; (C) - q; (D) - s

Solution : 

NOTE : The oxides and sulphides of less active metals like Hg, Cu & Pb are unstable to heat and hence no reducing agent is required. They undergo self reduction.
(A) 2Cu₂S + 3O₂ →2Cu₂O+ 2SO₂ ;
Cu₂S + 2Cu₂O →6Cu + SO₂

(B) 2PbS + 3O₂ → 2PbO + 2SO₂ ;
PbS + 2PbO → 3Pb + SO₂
Hence (A) → (p), (r)
NOTE : The oxides of less electropositive metals like Pb, Zn, Fe, Sn, Cu, etc. are reduced by strongly heating them with coke or coal.

PbO + C → Pb + CO₂ ;
2Cu₂O+ C → 4Cu + CO₂
Hence (B) → (p), (r)
Extraction from argentite (Ag₂S)
Ag₂S + 2NaCN  Na₂S + 2AgCN;
Sod. argentocyanide soluble
AgCN+ NaCN → Na[Ag(CN)₂ ]
Zn, being more electropositive than Ag, displaces Ag from the complex.
2Na[Ag(CN)₂ ] + Zn → Na₂[Zn(CN)₄ ] + 2Ag¯
Hence (C) →(q)

Among the halides of boron, BI₃ is unstable because of the large size of Iodine and small size of boron atom. Hence it decomposes to give boron. Thus, (D) → (s).

2. Match the conversions in Column I with the type(s) of reaction(s) given in Column II.      (2008 - 6M)

Ans : (A) - p; (B) - q; (C) - p, r; (D) - p, s

3. Match the anionic species given in Column-I that are present in the ore(s) given in Column-II. (JEE Adv. 2015)

Ans: (A)- p,q,s, (B)- t, (C)- q, r, (D)- r

Solution :