Extraction & D & F Block - Class 12 MCQ

dolomite is the ore of zinc                

galena is the ore of mercury    

pyrolusite is the ore of iron            

cassiterite is the ore of tin.

Process of removal of impurities            

Process of heating ore at high temperature    

Extraction of metal from ore            

None of the above

Electrolyte is magnesium chloride containing a little of NaCI and NaF    

Air tight iron pot acts as a cathode    

Electrolysis is done in the atmosphere of coal gas.    

Molten magnesium is heavier than the electrolyte.

AgNO₂        

silver nitride    

Ag        

Ag₂O

4        

2        

6        

5

AgCN        

Ag        

Ag(CN)₂        

Na[Ag(CN)₂]

It reacts with NaOH and glucose to give Cu₂O    

It reacts with KCI to give Cu₂CI₂    

It gives CuO on strong heating in air        

It reacts with KI to give iodine

Cupellation        

Poling        

Van Arkel    

Zone refining

O₂ and CO respectively                

O₂ and Zn dust respectively    

HNO₃ and Zn dust respectively            

HNO₃ and CO respectively

The white solid dissolves to form a colourless solution    

The white solid dissolves to form a green solution    

The white solid turns blue but does not dissolve    

The white solid dissolves to form a blue solution

ammonium hydroxide dissolves in copper sulphate    

copper sulphate solution reacts with K₄[Fe(CN)₆]    

ferric chloride reacts with sodium ferrocyanide    

anhydrous white CuSO₄ is dissolved in water

by heating cupric chloride with chlorine        

by the electrolysis of cupric chloride conatining HCI    

by heating cupric chloride with conc. HCI and copper turnings

by passing H₂ over CuCI₂

Acidic solution of Cu(II) sulphate is used        

H₃O⁺ ion is discharged at cathode    

Anode is made of impure copper            

OH^- is discharged at anode

to expel the dissolved gases in the blister copper    

to bring the impurities to surface and oxidise them    

to increase the carbon content of copper        

to reduce the metallic oxide impurities with hydrocar-bon gases liberated  from the wood.

X is Ag₂S and Y is Na₃[Ag(S₂O₃)₂]            

X is Na₃[Ag(S₂O₃)₂] and Y is Ag₂S    

X is Ag₂S₂O₃ and Y is Ag₂S                

X is Ag₂S₂O₃ and Y is Na₃[AgS₂O₃)₂]

CuO        

Ag₂O        

ZnO        

Sb₂O₃

Fe+H₂SO₄(aq.)    

Fe+steam    

Cu+HCI(g)    

Na+C₂H₅OH

It may not be removed as slag with silica        

It may not evaporate in the furnace    

presence of it may increase the m.p. of charge    

none of the above

of the sulphide is greater than CS₂ and H₂S    

 is negative for roasting of sulphide ore to oxide    

Roasting of the sulphide to oxide is thermodynamically feasible    

Carbon and hydrogen are suitable reducing agents for metal sulphides.

Al(OH)₃ in NaOH solution                

an aqueous solution of AI₂(SO₄)₂    

a molten mixture of Al₂O₃ and Na₃AlF₆        

a molten mixture of Al₂O₃ and Al(OH)₃

A-P,R; B--R,Q; C-P;D-S,Q

A-P,R; B-P,R; C-Q;D-S

A-P,R; B-S;C-P;D-P,Q

A-P,Q; B-R,P; C-Q; D-S

In the highest oxidation states, the transition metal show basic character and form cationic complexes.    

In the highest oxidation states of the first five transition elements (Sc to Mn), all the 4s and 3d-electrons are used for bonding.    

Once the d⁵-configuration is exceeded, the tendency to involve all the 3d-electrons in bonding decreases.    

In addition to the normal oxidation states, the zero oxidation state is also shown by these elements in complexes.

It is prepared by heating mercury in chlorine        

It reduces stannic chloride    

It oxidizes stannous chloride            

It sublimes readily

ZnS is white solid which turns yellow on exposure to light.    

ZnS is precipitated on passing H₂S to aqueous NaZnO₂    

Basic zinc carbonate is    

HgCI₂ reacts with NH₃(g) to give [Hg(NH₃)₄]Cl₂ 

Cd rods are used in atomic reactions to slow down nuclear reaction    

Cd is a good absorber of neutrons        

CdS is used as pigment        

All of the above

    K₂[HgI₄]        

    Hg₂O(NH₂)I    

Co²⁺ ions    

Cd²⁺ ions        

Cu²⁺ ions        

Ni²⁺ ions

CI₂ is passed into an aqueous KMnO₄ solution    

MnO₂ is fused with KOH in air        

formaldehyde reacts with KMnO₄ in presence of strong alkali    

KMnO₄ reacts with concentrated H₂SO₄

(n-1) d-orbitals                    

(n-2) f-orbitals        

(n-1) d-orbitals and (n-1) f-orbitals            

(n-1) d-orbitals and ns-orbitals

La(OH)₃, is less basic than Lu(OH)₃

In lanthanoid series, ionic radius of Ln³⁺ ions decreases

La is actually an element of transition series rather than lanthanoid series

Atomic radii of Zr and Hf are same because of lanthanoid contraction