Refining

Q.

Which of the following metal is leached by the cyanide process?

1. $\mathrm{Al}$

2. $\mathrm{Ag}$

3. $\mathrm{Cu}$

4. $\mathrm{Na}$

Q.

Which refining method is used when the metal and the impurities have a low and high melting point, respectively is:

1. Vapour phase refining

2. Distillation

3. Liquation

4. Zone refining

Q.

The liquation method is used for the purification of -

1. Copper

2. Iron

3. Aluminium

4. Lead

Q. What is the basic principles of chromatography

Q.

Is Zn a reducing agent?

Q. The method of zone refining of metals is based on the principle of:
[1 mark]

1. Greater mobility of the pure metal than that of the impurity
2. Higher melting point of the impurity than that of the pure metal
3. Higher melting point of the solid metal than that of the impurity
4. Greater solubility of the impurity in the molten state than in the solid state

Q. Blast furnace is employed in the smelting of oxide ore with coke and flux in the metallurgy of

1. Iron
2. Copper
3. Lead
4. All of the above

Q. Assertion :In metallurgy calcination use for purification of metals Reason: Calcination is a chemical process wherein a carbonate ore or an oxide ore is strongly heated in the absence of air, to decompose it to remove volatile matter and moisture.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is incorrect but Reason is correct
4. Both Assertion and Reason are incorrect

Q. For the formation of $NaOH$ using Castner Kellner cell, cathode used is of metal

1. $Hg$
2. $Pt$
3. $Cu$
4. $Na$

Q. (Ag+Pb) alloy Meltand Zinc is added ​ (Ag+Pb+Zn)melt →Cool LayerX LayerY ​ Layer X contains zinc and silver Layer Y contains lead and silver but amount of silver in this layer is smaller than in the layer X X and Y Are immiscible layers All are correct statements

Q. Which of the following(s) is/are the requirements of metal to get refined by vapour phase refining method?

1. Metal should form a volatile compound with reagent
2. The volatile compound should be stable
3. Metal should have high boiling point
4. Both (a) and (b)

Q. Four metals and their methods of refinement are given
(i) $Ni,Cu,Zr,Ga$
(ii) Electrolysis, Van Arkel process, zone refining, Mond's process
Choose the right method for each:

1. $Ni$: Mond's process, $Cu$: Electrolysis, $Zr$: Van Arkel process, $Ga$: Zone refining
2. $Ni$: Mond's process, $Cu$: Van Arkel process, $Zr$: Zone refining, $Ga$: Electrolysis
3. None of the above
4. $Ni$: Electrolysis, $Cu$: Zone refining, $Zr$: Van Arkel process, $Ga$: Mond's process

Q. Complete the table:

	Method of preparation & Content
Pig Iron	...........i................
Cast Iron	...........ii...............
Wrought Iron	.........iii...............
Steel	............iv...........

Q. The method not used in metallurgy to refine the impure metal is

1. Mond's process
2. Amalgamation
3. van-Arkel process
4. Liquation

Q. The method of zone refining of metal is based on the principle of

1. Greater mobility of the pure metal than that of the impurity
2. Higher melting point of the impurity than that of the pure metal
3. Greater noble character of the solid metal than that of the impurity
4. Greater solubility of the impurity in molten state than in the solid state

Q. Which of the following reduction reactions are actually employed in the commercial extraction of metals?

1. $F{e}_2{O}_3+2Al\to A{l}_2{O}_3+2Fe$
2. $C{r}_2{O}_3+2Al\to A{l}_2{O}_3+2Cr$
3. $2Na\left[Au\right(CN{)}_2]+Zn\to N{a}_2[Zn\left(CN{)}_4\right]+2Au$
4. $C{u}_{2}O+H_2\to 2Cu+H_{2}O$

Q. Which of the following is correct ?

1. All of these
2. Zone refining method is based on the principle that the impurities are more soluble in the melt than in the solid state of the metal
3. Liquation process is used for metals like Sn
4. Distillation process is used for refining of metals having very low boiling points like Zn and Hg

Q. Which of the following statement is true about Brownian movement?

1. It depends on size of particle.
2. It depends on viscosity of the solution.
3. It depends on temperature.
4. All of the above.

Q. In which of the following pair(s), the minerals are converted in to metals by self-reduction process?

1. $C{u}_{2}S,PbS$
2. $PbS,HgS$
3. $PbS,ZnS$
4. $A{g}_{2}S,C{u}_{2}S$

Q. Assertion :Nickel is purified by reacting it with $CO$. Reason: Impurities present, form a volatile complex.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q. A metal obtained by auto reduction or self reduction _______________.

1. Na
2. Zn
3. Fe
4. Cu

Q. Outline the principles behind the refining of metals by the following methods:
(i) Zone refining method
(ii) Chromatographic method

Q. Assertion :Chromatography in general involves a mobile phase (a gas, a liquid or a supercritical fluid) and a stationary phase (like $A{l}_2{O}_3$ column). Reason: A compound which is less soluble in the stationary phase takes longer time travel through it than a component which is more soluble in the stationary phase.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q.

After extracting the crude metal from its ore, what should be the next logical step?

1. Pickling

2. Alloying

3. Pulverizing

4. Refining

Q. In the Castner process for the extraction of sodium, the anode is made of:

1. copper
2. iron
3. sodium
4. nickel

Q. During a column chromatography through $A{l}_2{O}_3$ column, a mixture of components A, B and C is passed through the column. On adding eluant, compound 'A' is eluted first then 'B' and in the end 'C'. Which of the following statements is correct?

1. The order of adsorption of A, B and C is C > B > A.
2. The order of adsorption of A, B and C is B > A > C.
3. The order of adsorption of A, B and C is A > B > C.
4. The order of adsorption of A, B and C is B > C > A.

Q. Heating a mixture of $C{u}_{2}O$ and $C{u}_{2}S$ will give.

1. $CuO+CuS$
2. $Cu+S{O}_3$
3. $Cu+S{O}_2$
4. $Cu(OH{)}_2+CuS{O}_4$

Q. Both potassium ferrocyanide & potassium ferricyanide are diamagnetic.

1. True
2. False

Q. Column chromatography involves separation of a mixture over a column of adsorbent (stationary phase) packed in a glass tube. Depending upon the degree of adsorption complete separation takes place. In the given column, three coloured bands x, y, z are formed. Identify the correct statement.

1. x, y and z are adsorbed to the same extent.
2. The most readily adsorbed component is retained near the top (x).
3. The most readily absorbed component comes down(z).
4. x, y, z layers are formed according to the wavelengths of the colours not on the basis of adsorption.