-
question_answer1)
Which of the following statements is true?
A)
Reduction of a metal oxide is easier if the metal formed is in liquid state at reduction temperature done
clear
B)
Reduction of metal oxide is normally less feasible at high temperature done
clear
C)
The oxidation of CO into \[C{{O}_{2}}\] will have a negative slope on Ellingham diagram done
clear
D)
The reactive metals have positive slope for oxidation on Ellingham diagram whereas non-reactive metals have a negative slope done
clear
View Solution play_arrow
-
question_answer2)
The main reaction occurring in blast furnace during the extraction of iron from haematite is
A)
\[F{{e}_{2}}{{O}_{3}}+3C\to 2Fe+3CO\] done
clear
B)
\[FeO+Si{{O}_{2}}\to FeSi{{O}_{3}}\] done
clear
C)
\[F{{e}_{2}}{{O}_{3}}+3CO\to 2Fe+3C{{O}_{2}}\] done
clear
D)
\[CaO+Si{{O}_{2}}\to CaSi{{O}_{3}}\] done
clear
View Solution play_arrow
-
question_answer3)
Flux is often added to remove impurities from an iron ore in a blast furnace. In the reactions slag and flux are
A)
\[CaSi{{O}_{3}}\] and \[Si{{O}_{2}}\] done
clear
B)
\[CaO\] and \[Si{{O}_{3}}\] done
clear
C)
\[CaSi{{O}_{3}}\] and \[CaO\] done
clear
D)
\[Si{{O}_{2}}\] and \[CaSi{{O}_{3}}\] done
clear
View Solution play_arrow
-
question_answer4)
Which one of the following ores is concentrated by chemical leaching method?
A)
Argentite done
clear
B)
Copper pyrite done
clear
C)
Cinnabar done
clear
D)
Galena done
clear
View Solution play_arrow
-
question_answer5)
Wolframite (\[FeW{{O}_{4}}\]) impurities present in cassiterite (\[Sn{{O}_{2}}\]) can be separated by the process of
A)
froth floatation done
clear
B)
zone refining done
clear
C)
electromagnetic separation done
clear
D)
gravity separation done
clear
View Solution play_arrow
-
question_answer6)
Annealing of steel is the process of heating steel
A)
to a bright red hot and then cooling it slowly done
clear
B)
to a bright red hot and then cooling it suddenly done
clear
C)
to a temperature much below redness and cooling it slowly done
clear
D)
none of the above done
clear
View Solution play_arrow
-
question_answer7)
Sulphide ores of metals are usually concentrated by froth floatation process. Which one of the following sulphide ores offers an exception and is concentrated by leaching?
A)
Sphalerite done
clear
B)
Galena done
clear
C)
Argentite done
clear
D)
Copper pyrites done
clear
View Solution play_arrow
-
question_answer8)
Poling process is used
A)
for the removal of \[C{{u}_{2}}O\] from Cu done
clear
B)
for the removal of \[A{{l}_{2}}{{O}_{3}}\] from Al done
clear
C)
for the removal of \[F{{e}_{2}}{{O}_{3}}\] from Fe done
clear
D)
In all the above done
clear
View Solution play_arrow
-
question_answer9)
Zone refining is based on the principle that..........
A)
impurities of low boiling metals can be separated distillation done
clear
B)
impurities are more soluble in molten metal than in solid metal done
clear
C)
different components of a mixture are differently adsorbed on an adsorbent. done
clear
D)
vapour of volatile compound can be decomposed in pure metal. done
clear
View Solution play_arrow
-
question_answer10)
In which of the following pair of metals, both are commercially extracted from their respective ores by self- reduction method?
A)
Zn, Cu done
clear
B)
Pb, Cu done
clear
C)
Sn, Zn done
clear
D)
Al, Ag done
clear
View Solution play_arrow
-
question_answer11)
In zone refining, pure metal is obtained at the
A)
Right end, if zone is travelling from left to right done
clear
B)
Left end, if zone is travelling from left to right done
clear
C)
Left end, if zone is travelling from right to left done
clear
D)
Centre, if zone is travelling from any side done
clear
View Solution play_arrow
-
question_answer12)
Copper matte is extracted from copper pyrites ore b) heating it in blast furnace. The method is based on the principle that:
A)
copper has more affinity for oxygen than sulphur at high temperature done
clear
B)
iron has less affinity for oxygen than sulphur at high temperature done
clear
C)
sulphur has less affinity for oxygen at high temperatun done
clear
D)
copper has less affinity for oxygen than sulphur at high temperature done
clear
View Solution play_arrow
-
question_answer13)
During the extraction of gold the following reactions take place \[Au+C{{N}^{-}}+{{H}_{2}}O\xrightarrow{{{o}_{2}}}X,\,X+Zn\to Y+Au\] Here, X and Y respectively are
A)
\[{{\left[ Au(C{{N}_{4}}) \right]}^{3-}}\] and \[{{\left[ Zn{{(CN)}_{4}} \right]}^{2-}}\] done
clear
B)
\[{{\left[ Au(C{{N}_{2}}) \right]}^{-}}\] and \[{{\left[ Zn{{(CN)}_{6}} \right]}^{4-}}\] done
clear
C)
\[{{\left[ Au(C{{N}_{4}}) \right]}^{4-}}\]and \[{{\left[ Zn{{(CN)}_{4}} \right]}^{2}}\] done
clear
D)
\[{{\left[ Au(C{{N}_{4}}) \right]}^{4-}}\] and \[{{\left[ Zn{{(CN)}_{4}} \right]}^{2-}}\] done
clear
View Solution play_arrow
-
question_answer14)
Which of the following statements is correct regarding the slag obtained during the extraction of a metal like copper or iron?
A)
The slag is lighter and has lower melting point than the metal done
clear
B)
The slag is heavier and has lower melting point than the metal done
clear
C)
The slag is lighter and has higher melting point than the metal done
clear
D)
The slag is heavier and has higher melting point than the metal done
clear
View Solution play_arrow
-
question_answer15)
Consider the following reactions at\[1000{}^\circ C\]. \[Zn(s)+\frac{1}{2}{{O}_{2}}(g)\to ZnO(g);\,\Delta {{G}^{o}}=-360\,kJ/mol\] \[C(s)+\frac{1}{2}{{O}_{2}}(g)\to CO(g);\,\Delta {{G}^{o}}=-400\,kJ/mol\] Choose the correct statement at \[1000{}^\circ C\].
A)
Zinc can be oxidized by CO done
clear
B)
Zinc oxide can be reduced by C done
clear
C)
Both statements [a] and [b] are true done
clear
D)
Both statements [a] and [b] are false done
clear
View Solution play_arrow
-
question_answer16)
In aluminum extraction by the Bayer's process, alumina is extracted from bauxite by sodium hydroxide at high temperature and pressures. \[A{{l}_{2}}{{O}_{3}}(s)+2O{{H}^{-}}(aq)\to 2A{{l}^{-}}_{2}(aq)+{{H}_{2}}O(\ell )\] Solid impurities such as \[F{{e}_{2}}{{O}_{3}}\] and \[Si{{O}_{2}}\] are removed and then Al\[{{(OH)}^{-}}_{4}\] is reprecipitated. \[Al{{(OH)}^{-}}_{4}\to A{{l}_{2}}{{O}_{3}}\cdot 2{{H}_{2}}O(s)+2O{{H}^{-}}(aq)\] In the industrial world
A)
carbon dioxide is added to precipitate the alumina done
clear
B)
Temperature and pressure are dropped and the super- saturated solution is seeded done
clear
C)
both [a] and [b] are practiced done
clear
D)
the water is evaporated. done
clear
View Solution play_arrow
-
question_answer17)
Roasting of sulphides gives the gas X as a by-product. This is a colorless gas produce choking smell of burnt sulphur, and causes great damage to respiratory organs as a result of acid rain. Its aqueous solution is acidic and acts as a reducing agent and it has never been isolated. The gas X is
A)
\[S{{O}_{2}}\] done
clear
B)
\[C{{O}_{2}}\] done
clear
C)
\[S{{O}_{3}}\] done
clear
D)
\[{{H}_{2}}S\] done
clear
View Solution play_arrow
-
question_answer18)
In the context of the Hall-Heroult process for the extraction of Al, which of the following statements is false?
A)
CO and \[C{{O}_{2}}\] are produced in this process done
clear
B)
\[A{{l}_{2}}{{O}_{3}}\] is mixed with \[Ca{{F}_{2}}\] which lowers the melting point of the mixture and brings conductivity done
clear
C)
\[A{{l}^{3+}}\] is reduced at the cathode to form Al done
clear
D)
\[N{{a}_{3}}AI{{F}_{6}}\] Serves as the electrolyte done
clear
View Solution play_arrow
-
question_answer19)
Oxidation states of the metal in the minerals haematite and magnetite, respectively, are
A)
II, III in haematite and III in magnetite done
clear
B)
II, III in haematite and II in magnetite done
clear
C)
II in haematite and II, III in magnetite done
clear
D)
III in the haematite and II, III in magnetite done
clear
View Solution play_arrow
-
question_answer20)
Which series of reactions correctly chemical reactions related to iron and its compound
A)
\[Fe\xrightarrow{C{{l}_{2}},\,heat}FeC{{l}_{2}}\xrightarrow{heat,air}FeC{{l}_{2}}\xrightarrow{Zn}Fe\] done
clear
B)
\[Fe\xrightarrow{{{O}_{2}},\,heat}F{{e}_{2}}{{O}_{4}}\xrightarrow{CO,{{600}^{0}}C}FeC{{l}_{3}}\xrightarrow{CO,{{700}^{0}}C}Fe\] done
clear
C)
\[Fe\xrightarrow{dil,{{H}_{2}}S{{O}_{4}}}Fe{{O}_{4}}\xrightarrow{{{H}_{2}}S{{O}_{4}},{{O}_{2}}}Fe{{(S{{O}_{4}})}_{3}}\xrightarrow{heat}Fe\] done
clear
D)
\[Fe\xrightarrow{{{O}_{2}},heat}FeO\xrightarrow{dil,{{H}_{2}}S{{O}_{4}}}FeS{{O}_{4}}\xrightarrow{heat}Fe\] done
clear
View Solution play_arrow
-
question_answer21)
Number of ores that have more than one metal or non-metal among: Horn silver, Quick silver, chromite, limonite, cinnabar, cryolite, caliche, diaspora, fluorspar.
View Solution play_arrow
-
question_answer22)
How many metallic ores are concentrated by magnetic separation method from the given ores? Cassiterite, pyrolusite, rutile, magnetite, galena, cinnabar.
View Solution play_arrow
-
question_answer23)
\[C{{u}^{2+}}+Fe\to Cu+F{{e}^{2+}}\] for this reaction to calculate \[\Delta G{}^\circ \] the formula \[\Delta G{}^\circ =-n\,FE{}^\circ \]is used. Find the value of n.
View Solution play_arrow
-
question_answer24)
Find the number of acidic flux from the given compounds: \[CaC{{O}_{3}},N{{a}_{2}}{{B}_{4}}{{P}_{7}},MgSi{{O}_{3}},FeSi{{O}_{3}},{{P}_{2}}{{O}_{5}}\]
View Solution play_arrow
-
question_answer25)
Ti is purified by following method: \[\text{Impure}\,\,\text{metal}\,+{{I}_{2}}\xrightarrow{\Delta }Ti\,{{I}_{x}}\] \[Vapours\,\xrightarrow[at\,\,high\,temp]{Heating}Pure\,metal\,+{{I}_{2}}\] What is the value of x?
View Solution play_arrow