181.Roasting of sulphides gives the gas X as a byproduct. This is a colourless gas with choking smell of burnt sulphur and causes great damage to respiratory organs as a result of acid rain. Its aqueous solution is acidic, acts as a reducing agent and its acid has never been isolated.The gas X is- (1)CO2
- (2)SO3
- (3)H2S
- (4)SO2(NEET2013)
182.The form of iron obtained from blast furnace is :- (1)Steel
- (2)Cast Iron
- (3)Pig Iron
- (4)Wrough Iron
183.For the formation of which compound in Ellingham diagram ΔG∘ becomes more and more negative with increase in temperature?- (1)CO
- (2)FeO
- (3)ZnO
- (4)Cu2O
184.The role of depressants in Troth Floation method* is to- (1)selectively prevent one component of the ore from coming to the froth.
- (2)reduce the consumption of oil for froth formation.
- (3)stabilize the froth.
- (4)enhance non-wettability of the mineral particles.
185.Which one of the following is a mineral of iron ?- (1)Malachite
- (2)Cassiterite
- (3)Pyrolusite
- (4)Magnetite
186.The compound(s) that is(are) removed as slag during the extraction of copper is : (1) CaO (2) FeO (3) A12O3 (4) ZnO (5) NiO Choose the correct answer from the options given below:- (1)(3) (4) Only
- (2)(1), (2), (5) Only
- (3)(1), (2) Only
- (4)(2) Only
187.In the extraction of copper from its sulphide ore, the metal finally obtained by the reduction of cuprous oxide with :- (1)iron (II) sulphide
- (2)carbon monoxide
- (3)copper (I) sulphide
- (4)sulphur dioxide
188.Which One of the following ores is known as Malachite- (1)Cu2O
- (2)Cu2S
- (3)CuFeS2
- (4)Cu(OH)2.CuCO3
189.The metal extracted by leaching with cyanide is- (1)Cu
- (2)Al
- (3)Na
- (4)Ag
190.In the metallurgical extraction of copper, following reaction is used: FeO + SiO2 → FeSiO3 FeO and FeSiO3 respectively are.- (1)gangue and flux
- (2)flux and slag
- (3)slag and flux
- (4)gangue and slag
191.In the equation, 4M + 8CN– + 2H2O + O2 → 4(M(CN)2)– + 4OH– Identify the metal (M). 4M + 8CN– + 2H2O + O2 → 4(M(CN)2)– + 4OH–- (1)Au
- (2)Fe
- (3)Zn
- (4)Cu
192.Among the following, the main reactions occurring in blast furnace during extraction of iron from haematite are (i) Fe2O3+3CO⟶2Fe+3CO2 (ii) FeO+SiO2⟶FeSiO3 (iii) Fe2O3+3C⟶2Fe+3CO (iv) CaO+SiO2⟶CaSiO3- (1)(i) and (ii)
- (2)(iii) and (iv)
- (3)(ii) and (iii)
- (4)none of the above
193.In the extraction of copper from its sulphide ore, the metal is finally obtained by the reduction of cuprous oxide with :- (1)Copper (I) sulphide (Cu2S)
- (2)Sulphur dioxide (SO2)
- (3)Iron sulphide (FeS)
- (4)Carbon monoxide (CO)
194.Which of the following is a carbonate ore?- (1)Cuprite
- (2)Siderite
- (3)Zincite
- (4)Bauxite
195.Considering Ellingham diagram, which of the following metals can be used to reduce alumina ?- (1)Fe
- (2)Cu
- (3)Mg
- (4)Zn
196.ΔG0 versus T plot in the Ellingham's diagram slopes downward for the reaction- (1)C + 21O2 → CO
- (2)CO + 21O2 → CO2
- (3)2Ag + 21O2 → Ag2O
- (4)Mg + 21O2 → MgO
197.The reaction representing the Mond process for metal refining is______- (1)Ni + 4CONi(CO)4
- (2)2K [Au(CN)2] + Zn K2 [Zn(CN)4] + 2 Au
- (3)Zr + 2I2 ZrI4
- (4)ZnO + C Zn + CO
198.Metal with low melting point containing impurities of high melting point can be purified by- (1)Zone refining
- (2)Vapor phase refining
- (3)Distillation
- (4)Liquation
199.In the leaching method, bauxite ore is digested with a concentrated solution of NaOH that produces 'X'. When CO2 gas is passed through the aqueous solution of 'X', a hydrated compound 'Y' is precipitated. 'X' and 'Y' respectively are :- (1)NaAlO2 and Al2(CO3)3.xH2O
- (2)Al(OH)3 and Al2O3.xH2O
- (3)Na[Al(OH)4] and Al2O3.xH2O
- (4)Na[Al(OH)4] and Al2(CO3)3.xH2O
200.The refining method used when the metal and the impurities have low and high melting temperatures, respectively, is :- (1)zone refining
- (2)vapour phase refining
- (3)liquation
- (4)distillation
201.Which one of the following is used to produce Al by electrolysis?- (1)Molten Al2O3+Na3AlF6 electrolyte, carbon coated steel vessel cathode, graphite anode
- (2)Al2O3+PbF2 electrolyte, steel cathode, graphite anode
- (3)Molten Al2O3+Na3AlF6 electrolyte, graphite cathode, steel anode
- (4)Al2O3+H2O electrolyte, graphite cathode, steel anode
202.Which of the following element is purified by vapour phase refining?- (1)Fe
- (2)Zr
- (3)Cu
- (4)Au
203.From the Ellingham graphs on carbon, which of the following statements is false?- (1)CO2 is more stable than CO at less than 983 K.
- (2)CO reduces Fe2O3 to Fe at less than 983 K.
- (3)CO is less stable than CO2 at more than 983 K.
- (4)CO reduces Fe2O3 to Fe in the reduction zone of Blast furnace.
204.Which one of the following ores is best concentrated by froth floatation method?- (1)Siderite
- (2)Galena
- (3)Malachite
- (4)Magnetite
205.Carbon cannot be used to produce magnesium by chemical reduction of MgO because :- (1)Carbon is not a powerful reducing agent
- (2)Magnesium reacts with carbon to form carbides
- (3)Carbon does not react with magnesium
- (4)Carbon is a non-metal
206.The solubilities of the impurities in the melt and solid states is not same. This principle is applied during the extraction of boron. This method is known as- (1)Poling
- (2)zone refining
- (3)liquation
- (4)van Arkel's method
207.van-Arkel method of refining zirconium involves- (1)removing all oxygen and nitrogen impurities
- (2)removing CO impurity
- (3)removing hydrogen impurity
- (4)removing silica impurity.
208.Copper is extracted from copper pyrites by- (1)reduction by coke
- (2)electrometallurgy
- (3)auto reduction
- (4)thermal decomposition.
209.Silver is obtained from Na[Ag(CN)2] by reaction with :- (1)Fe
- (2)Na
- (3)Zn
- (4)Au
210.Match the items of List-I with those of List-II and choose the correct option given below. List-IA. CalcinationB. RoastingC. Magnetic separationD. Carbon reduction of metalList-II1. Galena2. Magnetite3. Pyrometallurgy4. Malachite oxide Codes A BCD- (1)4132
- (2)4123
- (3)2432
- (4)3214
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