The value of ∆ f G O for the formation of Cr 2 O 3 is – 540 kJmol −1 and that of Al 2 O 3 is – 827 kJ mol −1 . The correct statement is-

Cr 2 O 3 cannot reduce Al 2 O 3 to Al

Al cannot reduce Cr 2 O 3 to Cr

The process in which Cl 2 is obtained as a by-product is -

In the electrolysis of molten NaCl, Cl 2 is obtained at the anode as a by-product.

In the electrolysis of aqueous HCl, Cl 2 is obtained at the cathode as a by-product.

In the electrolysis of aqueous NaCl, Cl 2 is obtained at the cathode as a by-product.

Chemistry - General Principles Processes Isolation Elements - Quiz-6

Common impurities present in bauxite are ........

a. $CuO$

b. $ZnO$

c. ${Fe}_{2} O_{3}$

d. ${SiO}_{2}$

Choose the correct option:

0%
(a, b)
0%
(b, c)
0%
(c, d)
0%
(a, d)

From the following, the ores that are concentrated by froth floatation are :

a. Haematite
b. Galena
c. Copper pyrites
d. Magnetite

Choose the correct option:

0%
(a, b)
0%
(b, c)
0%
(c, d)
0%
(a, d)

Reactions among the following that occurs during calcination are:

$a . {CaCO}_{3} \to CaO + {CO}_{2} b . 2 {FeS}_{2} + \frac{11}{2} O_{2} \to {Fe}_{2} O_{3} + {SO}_{2} c . {Al}_{2} O_{3} . {xH}_{2} O \to {Al}_{2} O_{3} + {xH}_{2} O d . ZnS + \frac{3}{2} O_{2} \to ZnO + {SO}_{2}$

Choose the correct option:

0%
(a, b)
0%
(b, c)
0%
(c, d)
0%
(a, c)

The ore among the following that can be reduced by carbon is :

a. Haematite

b. Zincite

c. Iron pyrites

d. Sphalerite

Choose the correct option:

0%
(a, b)
0%
(b, c)
0%
(c, d)
0%
(a, d)

The main reactions occurring in the blast furnace during extraction of iron from hematite

$a . {Fe}_{2} O_{3} + 3 CO \to 2 Fe + 3 {CO}_{2} b . FeO + {SiO}_{2} \to {FeSiO}_{3} c . {Fe}_{2} O_{3} + 3 C \to 2 Fe + 3 CO d . CaO + {SiO}_{2} \to {CaSiO}_{3}$

Choose the correct option:

0%
(a, b)
0%
(b, c)
0%
(c, d)
0%
(a, d)

Maximum impurity in Pig iron is :

0%
Mn
0%
Phosphorous
0%
Graphite
0%
Sulphur

The method of zone refining of metals is based on the principle of-

0%

Greater mobility of the pure metal than that of the impurity
0%

Higher melting point of the impurity than that of the pure metal
0%

Greater noble character of the solid metal than that of the impurity
0%

Greater solubility of the impurity in the molten state than in the solid

Copper can be extracted by hydrometallurgy but zinc cannot ,because -

0%

Metals required to displace iron react with water with the evolution of $H_{2}$ gas
0%

Non-metals required to displace iron react with water with the evolution of $H_{2}$ gas
0%

Metals required to displace zinc react with water with the evolution of $H_{2}$ gas
0%

Non-metals required to displace zinc react with water with the evolution of $H_{2}$ gas

The role of depressant in froth floatation process is -

0%

To separate two nitrite ores by selectively preventing one ore from forming froth.
0%

To separate two sulphide ores by selectively preventing one ore from forming froth.
0%

To separate two sulphide ores by selectively preventing both of them from forming froth.
0%

To separate two magnesium ores by selectively preventing both of them from forming froth.

The extraction of copper from pyrites is more difficult than from its oxide ores through reduction because -

0%

$∆ G_{f}$ of HCl is less than that of $H_{2} S and {CS}_{2}$
0%

$∆ G_{f}$ of HNO₃ is less than that of $H_{2} S and {CS}_{2}$
0%

$∆ G_{f}$ of ${Cu}_{2} S$ is less than that of $H_{2} S and {CS}_{2}$
0%

$∆ G_{f}$ of CuSO₄ is less than that of $H_{2} S and {CS}_{2}$

Out of C and CO, the better reducing agent at 673 K is -

0%
C because the value of $\Delta G_{(CO,CO_2)}$ is less than that of $\Delta G_{(C,CO_2)}$
0%
CO because the value of $\Delta G_{(CO,CO_2)}$ is less than that of $\Delta G_{(C,CO_2)}$
0%
C because the value of $\Delta G_{(C,CO_2)}$ is less than that of $\Delta G_{(CO,CO_2)}$
0%
CO because the value of $\Delta G_{(C,CO_2)}$ is less than that of $\Delta G_{(CO,CO_2)}$

The common elements present in the anode mud in electrolytic refining of copper are -

0%

Nitrogen, magnesium, sodium
0%

Silver, gold, platinum, and antimony
0%

Oxygen, sulphur, lithium
0%

Nitrogen, magnesium, oxygen

The role of silica in the metallurgy of copper is -

0%

To remove the iron oxide obtained during the process of roasting as ‘slag’.
0%

To remove the sulphur oxide obtained during the process of roasting as ‘slag’.
0%

To remove the nitrogen oxide obtained during the process of roasting as ‘slag’.
0%

To remove the aluminium oxide obtained during the process of roasting as ‘slag’.

The term “Chromatography” means -

0%

Technique for the preparation of mixtures.
0%

Technique for the separation of mixtures.
0%

Technique for the separation of ore.
0%

Technique for the preparation of aluminium.

The criterion followed while selecting the stationary phase of chromatography -

0%

The components of the sample have same melting point in the phase.
0%

The components of the sample have different melting point in the phase.
0%

The components of the sample have different solubility’s in the phase.
0%

The components of the sample have same solubility’s in the phase.

Which of the following statements is true about the refining of nickel -

0%

Nickel is heated in the presence of NO₂ to form nickel tetracarbonyl.
0%

Nickel is heated in the presence of CO to form nickel tetracarbonyl.
0%

Nickel is heated in the presence of CO₂ to form nickel tetracarbonyl.
0%

Nickel is heated in the presence of SO₂ to form nickel tetracarbonyl.

The correct way to separate alumina from silica in a bauxite ore associated with silica is -

0%

H₂SO₄ gas is passed through the resulting solution which result in precipitation of hydrated alumina.
0%

NO₂ gas is passed through the resulting solution which result in precipitation of hydrated alumina.
0%

CO₂ gas is passed through the resulting solution which result in precipitation of hydrated alumina.
0%

CO gas is passed through the resulting solution which result in precipitation of hydrated alumina.

‘Cast iron’ is different from ‘Pig iron' because -

0%

Cast iron is obtained by melting pig iron and coke using a hot air blast.
0%

Cast iron contains lower amount of carbon (3%) than pig iron.
0%

Unlike pig iron, cast iron is extremely hard and brittle.
0%

All of the above

The correct statement among the following is-

0%

All ores are minerals, but all minerals are not necessarily ores.
0%

Minerals are an economical source of metal
0%

Extraction of metal from ores is difficult.
0%

None of the above

Copper matte is put in silica lined converter to -

0%

Remove the remaining H₂SO₄ and H₂S present in the matte as slag.
0%

Remove the remaining MnO and FeS present in the matte as slag.
0%

Remove the remaining Fe₂O₃ and Fe₂S present in the matte as slag.
0%

Remove the remaining FeO and FeS present in the matte as slag.

The role of cryolite in the metallurgy of aluminium is -

0%

To decrease the melting point of the mixture from 2323 K to 1140 K
0%

To increase the electrical conductivity of $A l_{2} O_{3}$
0%

To decrease the electrical conductivity of $A l_{2} O_{3}$
0%

Both '1' and '2'

Leaching of low-grade copper ores does not involve

0%

Cu getting converted into Cu²⁺(aq) in acidic medium
0%

Cu getting converted into Cu²⁺(aq) in basic medium
0%

Cu²⁺(aq) getting reduced to Cu
0%

using bacteria in the presence of air.

Zinc is not extracted from zinc oxide by reduction using CO because:-
(Given: Ellingham diagram)

0%
$∆ {G_{f}}^{\circ}$ of Zn from ZnO is lower than that of $C O_{2}$ from CO
0%

$∆ G_{f}^{\circ}$ of ZnO from Zn is lower than that of $C O_{2}$ from CO
0%

ZnO is less stable than CO
0%

ZnO is more stable than CO

The value of ∆_fG^O for the formation of ${Cr}_{2} O_{3}$ is – 540 kJmol⁻¹and that of Al₂O₃ is – 827 kJ mol⁻¹. The correct statement is-

0%

Cr can reduce Al₂O₃ to Al
0%

Cr₂O₃ cannot reduce Al₂O₃ to Al
0%

Al can reduce ${Cr}_{2} O_{3}$ to Cr
0%

Al cannot reduce ${Cr}_{2} O_{3}$ to Cr

The better reducing agent for ZnO among the following is -

0%

C
0%

CO
0%

CO₂
0%

${CO}_{3}^{2 -}$

The process in which Cl₂ is obtained as a by-product is -

0%

In the electrolysis of aqueous HCl, Cl₂ is obtained at the cathode as a by-product.
0%

In the electrolysis of aqueous NaCl, Cl₂ is obtained at the cathode as a by-product.
0%

In the electrolysis of molten NaCl, Cl₂ is obtained at the anode as a by-product.
0%

None of the above

The role of a graphite rod in the electrometallurgy of aluminum is-

0%

To prevent the formation of CO at the anode.
0%

To prevent the formation of $O_{2}$ at the anode.
0%

To prevent the formation of CO at the cathode.
0%

To prevent the formation of $O_{2}$ at the cathode.

Study the Ellingham diagram for the formation of some oxides and answer the following question.At the point of intersection of Al2O3 and MgO curves (A), G^0 becomes zero for the reaction, 2/3Al2O3 +

Al can reduce MgO under the following condition -

0%

Above 500°C, Al can reduce MgO
0%

Below 500°C, Al can reduce MgO
0%

Below 1350°C, Al can reduce MgO
0%

Above 1350°C, Al can reduce MgO

Consider the following statements:

a. Zone refining method is useful for producing semiconductors and other metals of very high purity.

b. Zone refining method is based on the principle that "the impurities are less soluble in the melt than in the solid-state of the metal".

c. In column chromatography, the most readily adsorbed substances are retained near the top.

d. In column chromatography, the stationary phase is packed in a glass tube.

Select the correct statements.

0%

a, c, d
0%

a, b
0%

b, c
0%

a, b, c, d

The chemical reactions taking place in the extraction of zinc from zinc blende is

0%

$2 ZnS + 3 O_{2} \to 2 ZnO + 2 {SO}_{2}$
0%

$ZnO + C \overset{1673 K}{\to} Zn + CO$
0%

Both 1 and 2
0%

None of the above

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Practice Chemistry Quiz Questions and Answers

0:0:1

Practice Chemistry Quiz Questions and Answers

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