Metallurgy PYQs Set 4 (PDF)

Set 4 of 8 · Questions 91-120 of 216

In the print window choose “Save as PDF”. The file prints without a web address or date line.

Mere Teacher · Previous Year Questions NEET Chemistry · Metallurgy · Set 4 (Q91-120)
Scan or visit mereteacher.com for free PYQ practice, timed CBT tests, step-by-step solutions and BroBot AI. Answers and solutions are free with a sign-up.
91. $The ore that is concentrated by froth floatation process is$ (1) $cinnabar$ (2) $bauxite$ (3) $malachite$ (4) $zincite.$ 92. $In chromite ore, the oxidation number of iron, and chromium are respectively$ (1) $+ 3, + 2$ (2) $+ 3, + 6$ (3) $+ 2, + 6$ (4) $+ 2, + 3$ 93. $The alloy used in the construction of aircrafts is :$ (1) $Mg - Al$ (2) $Mg - Zn$ (3) $Mg - Sn$ (4) $Mg - Mn$ 94. $Statement I : Leaching of gold with cyanide ion in absence of air / O_{2} leads to cyano complex of Au(III). Statement II : Zinc is oxidized during the displacement reaction carried out for gold extraction.In the light of the above statements, choose the correct answer from the options given below.$ (1) $Both Statement I and Statement II are correct$ (2) $Both Statement I and Statement II are incorrect$ (3) $Statement I is correct but Statement II is incorrect$ (4) $Statement I is incorrect but Statement II is correct$ 95. $Electrolytic refining is used to purify which of the following metals?$ (1) $Cu and Zn$ (2) $Ge and Si$ (3) $Zr and Ti$ (4) $Zn and Hg$ 96. $During the extraction of gold the following reactions take place. Au + CN^{-} + H_{2} O \to O_{2} [X] [X] + Zn \to [Y] + Au X and Y are respectively$ (1) $Au(CN)2-and (Zn (CN)_{6})^{4 -}$ (2) $(Au (CN)_{4})^{2 -} and (Zn (CN)_{4})^{2 -}$ (3) $(Au (CN)_{4})^{3 -} and (Zn (CN)_{4})^{2 -}$ (4) $Au(CN)2-and (Zn (CN)_{4})^{2 -}$ 97. $The function of Fe (OH)_{3} in the contact process is$ (1) $to detect colloidal impurity$ (2) $to remove moisture$ (3) $to remove dust particles$ (4) $to remove arsenic impurity.$ 98. $An Ellingham diagram provides information about$ (1) $the temperature dependence of the standard Gibbs energies of formation of some metal oxides$ (2) $the pressure dependence of the standard electrode potentials of reduction reactions involved in the extraction of metals$ (3) $the conditions of pH and potential under which a species is thermodynamically stable$ (4) $the kinetics of the reduction process$ 99. $Given below are two statements statements Statement I :- In froth floatation method a rotating paddle agitates the mixture to drive air out of it. Statement II :- Iron pyrites are generally avoided for extraction of iron due to environmental reasons. In the light of the above statements, choose the correct answer from the options given below :-$ (1) $Both Statement I and Statement II are true$ (2) $Statement I is false but Statement II is true$ (3) $Statement I is true but Statement II is false$ (4) $Both Statement I and Statement II are false$ 100. $Match the following items in column I with the corresponding items in column II . Column- I Column- II (i) Na_{2} CO_{3} \cdot 10 H_{2} O (A) Portland cementingredient (ii) Mg (HCO_{3})_{2} (B) Castner-Kellner process (iii) NaOH (C) Solvay process (iv) Ca_{3} Al_{2} O_{6} (D) Temporary hardness$ (1) $(i) \to (B); (ii) \to (C); (iii) \to (A); (iv) \to (D)$ (2) $(i) \to (C); (ii) \to (B); (iii) \to (D); (iv) \to (A)$ (3) $(i) \to (D); (ii) \to (A); (iii) \to (B); (iv) \to (C)$ (4) $(i) \to (C); (ii) \to (D); (iii) \to (B); (iv) \to (A)$ 101. $Match List -I with List - II List I (Metal) (1) Aluminium (2) Iron (3) Copper (4) Zinc List II (Ores) (i) Siderite (ii) Calamine (iii) Kaolinite (iv) Malachite Choose the correct answer from the options given below:$ (1) $(1)-(iv), (2)-(iii), (3)-(ii), (4)-(i)$ (2) $(1)-(i), (2)-(ii), (3)-(iii), (4)-(iv)$ (3) $(1)-(iii), (2)-(i), (3)-(iv), (4)-(ii)$ (4) $(1)-(ii), (2)-(iv), (3)-(i), (4)-(iii)$ 102. $The statement that is INCORRECT about Ellingham diagram is$ (1) $provides idea about the reaction rate.$ (2) $provides idea about free energy change.$ (3) $provides idea about changes in the phases during the reaction.$ (4) $provides idea about reduction of metal oxide.$ 103. $In the Hall-Heroult process, aluminium is formed at the cathode. The cathode is made out of:$ (1) $Pure aluminium$ (2) $Carbon$ (3) $Copper$ (4) $Platinum$ 104. $The metal which is extracted by oxidation and subsequent reduction from its ore is :$ (1) $Al$ (2) $Ag$ (3) $Cu$ (4) $Fe$ 105. $“Metals are usually not found as nitrates in their ores.” Out of the following two (I and II) reasons which is/are true for the above observation? I. Metal nitrates are highly unstable. II. Metal nitrates are highly soluble in water.$ (1) $I is false but II is true.$ (2) $I is true but II is false.$ (3) $I and II are true.$ (4) $I and II are false (2015, Cancelled)$ 106. $Given are two statements one is labelled as Assertion A and other is labelled as Reason R. Assertion A :Magnesium can reduce A 1_{2} O_{3} at a temperature below 1350°C, while above 1350°C aluminium can reduce MgO. Reason R : The melting and boiling points of magnesium are lower than those of aluminium. In light of the above statements, choose most appropriate answer from the options given below:$ (1) $Both A and R are correct, and R is correct explanation of A.$ (2) $Both A and R are correct, but R is NOT the correct explanation of A.$ (3) $A is correct R is not correct.$ (4) $A is not correct. R is correct.$ 107. $Sulphide ores of metals are usually concentrated by Froth floatation process. Which one of the following sulphide ores offers an exception and is concentrated by chemical leaching ?$ (1) $Sphalerite$ (2) $Argentite$ (3) $Galena$ (4) $Copper pyrite$ 108. $Al_{2} O_{3} was leached with alkali to get X. The solution of X on passing of gas Y, forms Z. X, Y and Z respectively are:$ (1) $X = Na (Al (OH)_{4}), Y = C O_{2}, Z = A l_{2} O_{3} ∙ x H_{2} O$ (2) $X = Na (Al (OH)_{4}), Y = S O_{2}, Z = A l_{2} O_{3}$ (3) $X = Al (OH)_{3}, Y = S O_{2}, Z = A l_{2} O_{3} ∙ x H_{2} O$ (4) $X = Al (OH)_{3}, Y = C O_{2}, Z = Al_{2} O_{3}$ 109. $The process which invovles the treatment of the ore with a suitable reagent so as to make it soluble but not impurities is called$ (1) $Froth floatation$ (2) $Roasting$ (3) $Hydrometallurgy$ (4) $Leaching$ 110. $The idea of froth floatation method came from a person X and this method is related to the process Y of ores, X and Y respectively, are:$ (1) $fisher woman and concentration$ (2) $washer woman and concentration$ (3) $fisher man and reduction$ (4) $washer man and reduction$ 111. $Sulfide ores are common for the metals :$ (1) $Ag, Cu and Pb$ (2) $Ag, Cu and Sn$ (3) $Ag, Mg and Pb$ (4) $Al, Cu and Pb$ 112. $The metal extracted by leaching with a cyanide is :$ (1) $Mg$ (2) $Ag$ (3) $Cu$ (4) $Na$ 113. $Extraction of gold and silver involves leaching with CN- ion. Silver is later recovered by :$ (1) $liquation$ (2) $distillation$ (3) $zone refining$ (4) $displacement with Zn$ 114. $The correct statement regarding the given Ellinghamdiagram is:$ (1) $At 1400^{\circ} C, Al can be used for the extraction of Znfrom ZnO$ (2) $At 500^{\circ} C, coke can be used for the extraction of Znfrom ZnO$ (3) $Coke cannot be used for the extraction of Cufrom Cu_{2} O$ (4) $At 800^{\circ} C, Cu can be used for the extraction of Znfrom ZnO$ 115. $The plot shows the variation of -ln Kp versus temperature for the two reactions. M(s) + \frac{1}{2} O_{2} (g) \to MO(s) and C(s) + \frac{1}{2} O_{2} (g) \to CO(s) Identify the correct statement:$ (1) $At T > 1200 K, carbon will reduce MO(s) to M(s).$ (2) $At T < 1200 K, oxidation of carbon is unfavourable.$ (3) $Oxidation of carbon is favourable at all temperatures.$ (4) $At T < 1200 K, the reaction MO(s) + C(s) \to M(s) + CO(g) is spontaneous$ 116. $The reducing agent in the given equations:$ (1) $Zn$ (2) $O_{2}$ (3) $H_{2} O$ (4) $CN^{-}$ 117. $Match List I with List II : (Both having metallurgical terms) Choose the correct answer from the options given below :$ (1) $(a)-(iii), (b)-(ii), (c)-(i), (d)-(iv)$ (2) $(a)-(iii), (b)-(iv), (c)-(i), (d)-(ii)$ (3) $(a)-(iv), (b)-(i), (c)-(iii), (d)-(ii)$ (4) $(a)-(iv), (b)-(iii), (c)-(ii), (d)-(i)$ 118. $Carbon cannot reduce Fe_{2} O_{3} to Fe at a temperature below 983 K because$ (1) $free energy change for the formation of CO is more negative than that of Fe_{2} O_{3}$ (2) $CO is themodynamically more stable than Fe_{2} O_{3}$ (3) $carbon has higher affinity towards oxygen than iron$ (4) $iron has higher affinity towards oxygen than carbon.$ 119. $Δ G^{\circ} vs T plot in the Ellingham's diagram slopes downwards for the reactions$ (1) $Mg + O_{2} \to MgO$ (2) $2 Ag + O_{2} \to Ag_{2} O$ (3) $C + O_{2} \to CO$ (4) $none of the above$ 120. $Aluminium is extracted from alumina (Al_{2} O_{3}) by electrolysis of a molten mixture of$ (1) $A l_{2} O_{3} + H F + N a A l F_{4}$ (2) $A l_{2} O_{3} + C a F_{2} + N a A l F_{4}$ (3) $A l_{2} O_{3} + N a_{3} A l F_{6} + C a F_{2}$ (4) $A l_{2} O_{3} + K F + N a_{3} A l F_{6} (2012)$