$XC{l}_2\left(excess\right) + YC{l}_2 \to XC{l}_4+Y\downarrow ;$ 

$YO \underset{>400°}{\overset{∆}{\to }}\frac{1}{2}{O}_2+ Y,$

Ore of Y would be:

(a) Siderite               

(b) Cinnabar

(c) Malachite             

(d) Hornsilver

Leaching of Ag₂S is carried out by heating it with a dilute solution of:

1. NaCN only                     

2. HCl

3. NaOH                           

4. NaCN in presence of O₂

Leaching is commercially carried out for in the concentration of:

(1) Galena                           

(2) Argentite

(3) Copper pyrites               

(4) tin stone

NaCN is sometimes added in the froth flotation process as depressant when ZnS and PbS minerals are expected because:

1. $Pb{\left(CN\right)}_2$ is precipitated while no effect on ZnS

2. ZnS forms soluble complex $N{a}_2\left[Zn{\left(CN\right)}_4\right]$ while PbS forms froth

3.  PbS forms soluble complex $N{a}_2\left[Pb{\left(CN\right)}_4\right]$ while ZnS forms froth

4.  NaCN is never added in froth floatation process

Give the correct order of initials T or F for following statements. Use T if statement is true and F if it is false.

(i) In Gold schmidt thermite process aluminium acts as a reducing agent.

(ii) Mg is extracted by electrolysis of aq. solution of $MgC{l}_2$

(iii) Extraction of Pb is possible by carbon reduction method

(iv) Red Bauxite is purified by Serpeck's process

(1) TTTF                               

(2) TFFT

(3)FTTT                               

(4) TFTF

A substance that can act as collector in the froth floatation method is -

1. Sodium xenate.             

2. Sodium pyrophosphate.

3. Sodium nitroprusside.   

4. Sodium ethyl xanthate. 

$FeC{r}_2{O}_4$ (chromite) is converted to Cr by following steps :

$Chromite\stackrel{I}{\to }NaCr{O}_4\stackrel{II}{\to }C{r}_2{O}_3\stackrel{III}{\to }Cr$

Reagents in I, II and III step might be:

          I-Step              II-Step                   III-Step

(a)$N{a}_{2}C{o}_3/air,∆$          C                             C

(b)NaOH/air,$∆$               C, $∆$                        Al, $∆$

(c)$N{a}_{2}C{o}_3/air,∆$          C, $∆$                         C, $∆$

(d)conc.$H_{2}S{O}_4, ∆$         $N{H}_{4}Cl, ∆$                  $C, ∆$

What is the composition of the anode mud used in the electrolytic refining of silver?

1. Zn, Cu, Ag, Au

2. Zn, Ag, Au

3. Cu, Ag, Au

4. Au only

Incorrect statement for the Hall-Heroult process is:

Correct match is:

(1) Bayer's method                 $—$ $N{a}_{2}C{O}_3$

(2) Matte                               $—$$98\%C{u}_{2}S+ 2\%FeS$

(3) van Arkel method              $—$$AgI$

(4) Thomas slag                     $—$Raw material for cement industry