Metallurgy PYQs Set 8 (PDF)

Set 8 of 8 · Questions 211-225 of 225

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Mere Teacher · Previous Year Questions JEE Main Chemistry · Metallurgy · Set 8 (Q211-225)
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211. $Which one of the following ores is best concentrated by froth floatation method?$ (1) $Siderite$ (2) $Galena$ (3) $Malachite$ (4) $Magnetite$ 212. $Carbon cannot be used to produce magnesium by chemical reduction of MgO because :$ (1) $Carbon is not a powerful reducing agent$ (2) $Magnesium reacts with carbon to form carbides$ (3) $Carbon does not react with magnesium$ (4) $Carbon is a non-metal$ 213. $The solubilities of the impurities in the melt and solid states is not same. This principle is applied during the extraction of boron. This method is known as$ (1) $Poling$ (2) $zone refining$ (3) $liquation$ (4) $van Arkel's method$ 214. $van-Arkel method of refining zirconium involves$ (1) $removing all oxygen and nitrogen impurities$ (2) $removing CO impurity$ (3) $removing hydrogen impurity$ (4) $removing silica impurity.$ 215. $Copper is extracted from copper pyrites by$ (1) $reduction by coke$ (2) $electrometallurgy$ (3) $auto reduction$ (4) $thermal decomposition.$ 216. $Silver is obtained from Na[Ag(CN)2] by reaction with :$ (1) $Fe$ (2) $Na$ (3) $Zn$ (4) $Au$ 217. $Match the items of List-I with those of List-II and choose the correct option given below. List-I A. Calcination B. Roasting C. Magnetic separation D. Carbon reduction of metal List-II 1. Galena 2. Magnetite 3. Pyrometallurgy 4. Malachite oxide Codes A B C D$ (1) $4132$ (2) $4123$ (3) $2432$ (4) $3214$ 218. $When metal 'M' is treated with NaOH, a white gelatinous precipitate 'X' is obtained, which is soluble in excess of NaOH. Compound 'X' when heated strongly gives an oxide which is used in chromatography as an adsorbent. The metal 'M' is :$ (1) $Al$ (2) $Fe$ (3) $Zn$ (4) $Ca$ 219. $Extraction of copper by smelting uses silica as an additive to remove :$ (1) $FeS$ (2) $FeO$ (3) $C u_{2} S$ (4) $C u_{2} O$ 220. $Extraction of copper from copper pyrite (C u F e S_{2}) involves$ (1) $crushing followed by concentration of the ore by froth-flotation$ (2) $removal of iron as slag$ (3) $self-reduction step to produce ‘blistercopper’ following evolution of S O_{2}$ (4) $refining of ‘blister copper’ by carbon reduction$ 221. $Among the reactions (a)-(d), the reaction(s) that does/do not occur in the blast furnace during the extraction of iron is/are (a) CaO + Si O_{2} \to CaSi O_{3} (b) 3F e_{2} O_{3} + CO \to 2F e_{3} O_{4} + C O_{2} (c) FeO + Si O_{2} \to FeSi O_{3} (d) FeO \to Fe + \frac{1}{2} O_{2}$ (1) $a & b$ (2) $a,b &c$ (3) $c &d$ (4) $a, b, c, d$ 222. $Calamine is an ore of :$ (1) $Zinc$ (2) $Aluminium$ (3) $Iron$ (4) $Copper$ 223. $Cryolite is$ (1) $Na_{3} AIF_{6} and is used in the electrolysis of alumina for lowering the melting point of alumina only$ (2) $Na_{3} AlF_{6} and is used in the electrolytic refining of alumina$ (3) $Na_{3} AlF_{6} and is used in the electrolysis of alumina for decreasing electrical conductivity$ (4) $Na_{3} AlF_{6} and is used in the electrolysis of alumina for lowering the melting point and increasing the conductivity of alumina.$ 224. $The purest form of commercial iron is:$ (1) $cast iron$ (2) $scrap iron and pig iron$ (3) $pig iron$ (4) $wrought iron$ 225. $(a) Baryte, (b) Galena, (c) Zinc blende and (d) Copper pyrites. How many of these minerals are sulphide based?$