Extraction of Zinc

Q.

What happens when steam is passed over red hot iron? Write the equation.

Q. Benzyl phenyl ether (PhCH_2­OPh) on cleavage with HI gives:

1. 
2. 
3. 
4. 

Q. Using Ellingham diagram, predict which metal can readily reduce the $C{u}_{2}O$ to $Cu$ at ${400}^{o}C$.

Ellingham diagram:

1. $Fe$
2. $Al$
3. $Mg$
4. $Zn$

Q. $S_1:$ In electrolytic refining, the impurities from the blister copper deposits anode mud which contains antimony, selenium, tellurium, silver, gold and platinum. (from copper pyrites)
$S_2:$ The low grade ore of copper is leached with acid and is then treated with scrap iron or $H_2$ to get copper.
$S_3:$ Siderite, curpite and argentite are oxide ores.
$S_4:$ Zone refining is very useful for producing semiconductor and other metals of very high purity, e.g., germanium, silicon, boron, gallium and indium.
Which of the following option is correct.
(T: True, F: False)

1. T F T T
2. F T F F
3. F F T T
4. T T F T

Q. Extraction of zinc from zinc blende is achieved by:

1. roasting followed by reduction with carbon

2. electrolytic reduction

3. roasting followed by reduction with another metal

4. roasting followed by self-reduction

Q. Benzyl chloride reacts with chlorobenzene in the presence of dry ether to give

1. Dibenzyl
2. Diphenyl methane
3. Methyl benzyl chloride
4. o-Phenyl touene

Q. $A{l}_2{O}_3$ can be reduced by carbon at a temperature of :

1. ${30}^{\circ }C$
2. ${500}^{\circ }C$
3. ${1000}^{\circ }C$
4. $>{2500}^{\circ }C$

Q. 29.why the hybridisation of [Cu(NH3)4]+2 is sp2d and not dsp2

Q. Which of the following statements is not correct about Ellingham diagram?

1. $\Delta G$ increases with an increase in temprature
2. It consists of plots of ${\Delta }_f{G}^{\circ }vsT$ for formation of oxide
3. It express the kinetic of the reduction process
4. None of the above

Q.

Give the name and formulae of the main ores of iron and zinc.

Q. The reaction $2ZnS+3O_2\to 2ZnO+2S{O}_2$ in the metallurgical process of zinc is called

1. Calcination
2. Cupellation
3. Smelting
4. Roasting

Q.

Why is zinc not extracted from zinc oxide through reduction using CO?

Q. In which of the following paramagnetic complex have pairing energy (P) is lower than splitting energy (Δ). (1) [NiF6]2– (2) [Co(H2O)6]3⊕ (3) [Cr(H2O)6]3+ (4) [RuF6]3–

Q.

The smelting of Zinc Oxide (obtained from roasted ZnS) happens __ the boiling point of Zinc metal

Q.

Write chemical reactions taking place in the extractions of zinc from zinc blende.

Q. Which of the following is an electrolyte used during the electrolytic refining of copper?

1. Copper sulphate solution
2. Copper sulphate solution acidified with sulphuric acid
3. Sulphuric acid
4. Copper chloride

Q. Common impurities present in bauxite are:

1. $CuO$
2. $ZnO$
3. $CaO$
4. $Si{O}_2$

Q. STATEMENT-1: Extraction of zinc from sphalerite ore involves the roasting followed by reduction with coke.
STATEMENT-2 : Zinc can be commercially extracted by hydrometallurgy.

1. STATEMENT-1 is True, STATEMENT-2 is True; STATEMENT-2 is NOT a correct explanation for STATEMENT-1
2. STATEMENT-1 is True, STATEMENT-2 is True; STATEMENT-2 is a correct explanation for STATEMENT-1
3. STATEMENT-1 is False, STATEMENT-2 is True
4. STATEMENT-1 is True, STATEMENT-2 is False

Q.

Which of the following is not an ore of Zinc?

1. Smithsonite

2. Zinc blende

3. Rutile

4. Wurtzite

Q. In the metallurgy of zinc, the reducing agent employed in reducing the zinc oxide to crude zinc metal in the last stage is:

1. $Al$
2. Coke
3. Water gas
4. $Li$
5. $H_2$ gas

Q. Write chemical reactions taking place in the extraction of zinc from zinc blende.

Q. Extraction of zinc from zinc blende is achieved by :

Q. Match each of the reactions given in $ColumnI$ with the corresponding product(s) given in $ColumnII$.
$$\begin{array}{cccc}& ColumnI& & ColumnII\\ A.& Cu+dil.HN{O}_3& p.& NO\\ B.& Cu+conc.HN{O}_3& q.& N{O}_2\\ C.& Zn+dil.HN{O}_3& r.& N_{2}O\\ D.& Zn+conc.HN{O}_3& s.& Cu(N{O}_3{)}_2\\ & & t.& Zn(N{O}_3{)}_2\end{array}$$

1. A. $⟶$ r, s; B. $⟶$ q, s; C. $⟶$ p, t; D. $⟶$ q, t;
2. A. $⟶$ r, s; B. $⟶$ q, s; C. $⟶$ r, t; D. $⟶$ q, t;
3. A. $⟶$ p, s; B. $⟶$ q, s; C. $⟶$ p, t; D. $⟶$ q, t;
4. A. $⟶$ p, s; B. $⟶$ q, s; C. $⟶$ r, t; D. $⟶$ q, t;

Q. Explain the extraction of zinc from its chief ore.

Q.

Dental amalgam is composed of:

1. Cu + Sn + Au + Hg +Co

2. Cd + Cu + Ni+ Au + Fe

3. Cu+ Sn + Hg + Ag + Zn

4. Hg + Ag + Cd + Au + Fe

Q. The metal which is deposited at the cathode during the electrolysis of the solution of $NaCl$ is:

1. Na
2. Mg
3. Cl
4. K

Q. Cannizaro’s reaction is not given by _____________. (A) 1-Methylcyclohexane carbaldehyde (B) Benzene carbaldehyde (C) Methanal (D) Ethanal

Q. Match the following metals listed in Column I with extraction processes listed in Column II:

Q. The balance reaction involved during extraction of zinc from its ore by roasting of zinc ore :

1. $ZnS\left(s\right)+O_2\stackrel{Heat}{\to }ZnO\left(s\right)+2S{O}_2\left(g\right)$
2. $2ZnS\left(s\right)+3O_2\stackrel{Heat}{\to }2ZnO\left(s\right)+2S{O}_2\left(g\right)$
3. $ZnS\left(s\right)+3O_2\stackrel{Heat}{\to }2ZnO\left(s\right)+S{O}_2\left(g\right)$
4. $ZnS\left(s\right)+3O_2\stackrel{Heat}{\to }ZnO\left(s\right)+2S{O}_2\left(g\right)$

Q. The standard reduction potentials of Zn and Ag in water at 298 K ate, $Z{n}^{+2}+2e^{-}\rightleftharpoons Zn;E^o=-0.76V$ and $A{g}^{+}+e^{-}\rightleftharpoons Ag;E^o=+0.80V$. Which of the following reactions take place?

1. $Z{n}^{+2}\left(aq\right)+2Ag\left(s\right)\to 2A{g}^{+}\left(aq\right)+Zn\left(s\right)$
2. $Zn\left(s\right)+2A{g}^{+}\left(aq\right)\to Z{n}^{+2}\left(aq\right)+2Ag\left(s\right)$
3. $Z{n}^{+2}\left(aq\right)+A{g}^{+}\left(aq\right)\to Zn\left(s\right)\left(aq\right)+Ag\left(s\right)$
4. $Zn\left(s\right)+Ag\left(s\right)\to Z{n}^{+2}\left(aq\right)+A{g}^{+}\left(aq\right)$