Chapter 18

In the following sequence of reactions. Identify (C) here? \(\mathrm{FeCO}_{3} \stackrel{\text { Heat in air }}{\longrightarrow}(\mathrm{A}) \stackrel{\text { Boil with } \mathrm{HCl}}{\longrightarrow}(\mathrm{B}) \stackrel{\mathrm{K}_{\mathrm{Fe}}(\mathrm{CN})_{6}}{\longrightarrow}(\mathrm{C})\) (a) \(\mathrm{K}_{3} \mathrm{Fe}(\mathrm{CN})_{6}\) (b) \(\mathrm{Fe}(\mathrm{CNS})_{3}\) (c) \(\mathrm{Fe}_{4}\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]_{3}\) (d) Both (b) and (c)

\(\mathrm{CuSO}_{4}\) decolourize on addition of \(\mathrm{KCN}\), the product is (a) \(\left[\mathrm{Cu}(\mathrm{CN})_{4}\right]^{2}\) (b) \(\mathrm{Cu}^{2+}\) gets reduced to form \(\left[\mathrm{Cu}(\mathrm{CN})_{4}\right]^{3-}\) (c) \(\mathrm{Cu}(\mathrm{CN})_{2}\) (d) \(\mathrm{CuCN}\)

Froth floatation process may be used to increase the concentration of the mineral in (a) chalcopyrites (b) bauxite (c) haematite (d) calamine

The black compound formed during the reaction between sodium thiosulphate and silver nitrate is (a) silver sulphite \(\left(\mathrm{Ag}_{2} \mathrm{SO}_{3}\right)\) (b) silver sulphate \(\left(\mathrm{Ag}_{2} \mathrm{SO}_{4}\right)\) (c) silver sulphide \(\left(\mathrm{Ag}_{2} \mathrm{~S}\right)\) (d) silver thiosulphate \(\left(\mathrm{Ag}_{2} \mathrm{~S}_{2} \mathrm{O}_{3}\right)\)

The fixing process of photographic film involves removal of unchanged silver bromide as (a) \(\mathrm{Na}_{2}\left[\operatorname{AgBr}\left(\mathrm{SO}_{3}\right)\right]\) (b) \(\mathrm{Na}_{3}\left[\mathrm{AgBr}\left(\mathrm{S}_{2} \mathrm{O}_{3}\right)\right]\) (c) \(\mathrm{Na}_{3}\left[\mathrm{Ag}\left(\mathrm{SO}_{3}\right)_{2}\right]\) (d) \(\mathrm{Na}_{3}\left[\mathrm{Ag}\left(\mathrm{S}_{2} \mathrm{O}_{3}\right)_{2}\right]\)

Amongst the following, the lowest degree of paramagnetism per mole of the compound at \(298 \mathrm{~K}\) will be shown by (a) \(\mathrm{MnSO}_{4} \cdot 4 \mathrm{H}_{2} \mathrm{O}\) (b) \(\mathrm{CuSO}_{4}^{4} 5 \mathrm{H}_{2} \mathrm{O}\) (c) \(\mathrm{FeSO}_{4} \cdot 6 \mathrm{H}_{2} \mathrm{O}\) (d) \(\mathrm{NiSO}_{4}^{4} \cdot 6 \mathrm{H}_{2}^{2} \mathrm{O}\)

Zn gives \(\mathrm{H}_{2}\) gas with \(\mathrm{H}_{2} \mathrm{SO}_{4}\) and \(\mathrm{HCl}\), but not with \(\mathrm{HNO}_{3}\) because (a) in electrochemical series, \(\mathrm{Zn}\) is above hydrogen (b) \(\mathrm{NO}_{3}^{-}\)ion is reduced in preference to hydronium ion (c) Zn acts as an oxidizing agent when reacts with \(\mathrm{HNO}_{4}\) (d) \(\mathrm{HNO}_{3}\) is weaker acid than \(\mathrm{H}_{2} \mathrm{SO}_{4}\) and \(\mathrm{HCl}\)

Among the following statements, the incorrect one is (a) calamine and siderite and carbonates (b) argentite and cuprite are oxides (c) zinc blende and pyrites are sulphides (d) malachite and azurite are ores of copper

Zinc-copper couple that can be used as a reducing agent is obtained by (a) zinc coated with copper (b) zinc and copper wires welded together (c) mixing zinc dust and copper gauze (d) copper coated with zinc

Anhydrous ferric chloride is prepared by (a) heating hydrated ferric chloride at a high temperature in a stream of air (b) heating metallic iron in a stream of dry chlorine gas (c) reaction of ferric oxide with hydrochloric acid (d) reaction of metallic iron with hydrochloric acid

Copper is extracted from copper pyrites ore by heating in a blast furnace. The method is based on the principle that (a) copper has less affinity for oxygen than sulphur at high temperature (b) sulphur has less affinity for oxygen at high temperature (c) iron has less affinity for oxygen than sulphur at high temperature (d) copper has more affinity for oxygen than sulphur at high temperature

Mixture of \((\mathrm{X})=0.02\) moles of \(\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{5} \mathrm{SO}_{4}\right] \mathrm{Br}\) and \(0.02\) mole of \(\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{5} \mathrm{Br}\right] \mathrm{SO}_{4}\) was prepared in 2 litre of solution 1 litre of mixture \((\mathrm{X})+\) excess \(\mathrm{AgNO}_{3} \longrightarrow(\mathrm{Y})\) 1 litre of mixture \((\mathrm{X})+\) excess \(\mathrm{BaCl}_{2} \stackrel{\longrightarrow}(\mathrm{Z})\) (a) \(0.01,0.01\) (b) \(0.02,0.01\) (c) \(0.01,0.02\) (d) \(0.02,0.02\)

Identify the correct order of solubility of \(\mathrm{Na}_{2} \mathrm{~S}, \mathrm{CuS}\) and \(\mathrm{ZnS}\) is aqueous medium (a) \(\mathrm{CuS}>\mathrm{ZnS}>\mathrm{Na}_{2} \mathrm{~S}\) (b) \(\mathrm{ZnS}>\mathrm{Na}_{2} \mathrm{~S}>\mathrm{CuS}\) (c) \(\mathrm{Na}_{2} \mathrm{~S}>\mathrm{CuS}>\mathrm{ZnS}\) (d) \(\mathrm{Na}_{2}^{2} \mathrm{~S}>\mathrm{ZnS}>\mathrm{CuS}\)

For which of the following metals may be hydrometallurgical extractive method be employed? (a) copper (b) iron (c) chromium (d) tin

Pick out the incorrect statement among the following. (1) ferric alum is commonly known as Mohr's salt (2) cast iron cannot be welded (3) heating steel to a high temperature followed by quick quenching in water is called annealing (4) alnico is used for making utensils and automobile parts. (a) \(1,2,3\) (b) 1,3 (c) 2,4 (d) \(1,3,4\)

Which of the following are the advantages of using oxygen in place of air in steel industry? (1) it gives more pure product (2) the surface is free from nitrides (3) it makes the procedure faster, that is, more production (4) larger quantities can also be handled (a) 1,2 and 3 (b) 2 and 4 only (c) 2,3 and 4 (d) \(1,2,3\) and 4

When dilute HCl is added to a solution of substance (X) which is water soluble, a white precipitate (Y) is formed. Treatment of \((\mathrm{Y})\) with \(\mathrm{NH}_{4} \mathrm{OH}\) turns it black (Z). Treatment of (Y) with \(\mathrm{H}_{2} \mathrm{~S}\) also turns it black. Identify \((\mathrm{X})\) here? (a) \(\mathrm{HgO}\) (b) \(\mathrm{Hg}\left(\mathrm{NO}_{3}\right)_{2}\) (c) \(\mathrm{HgSO}_{4}\) (d) \(\mathrm{Hg}_{2}\left(\mathrm{NO}_{3}\right)_{2}\)

Compound \(\mathrm{X}\) (1) on strongly heating it gives two oxides of sulphur. (2) on adding aqueous \(\mathrm{NaOH}\) solution to its aqueous solution, a dirty green precipitate is obtained which starts turning brown on exposure to air. Identify X here. (a) \(\mathrm{CuSO}_{4} .5 \mathrm{H}_{3} \mathrm{O}\) (b) \(\mathrm{FeSO}_{4} \cdot 7 \mathrm{H}_{2} \mathrm{O}\) (c) \(\mathrm{ZnSO}_{4} \cdot 7 \mathrm{H}_{2} \mathrm{O}\) (d) \(\mathrm{Ag}_{2} \mathrm{~S}_{2} \mathrm{O}_{3}\)

A solution, when diluted with water and boiled, gives a white precipitate. On addition of excess \(\mathrm{NH}_{4} \mathrm{Cl} /\) \(\mathrm{NH}_{4} \mathrm{OH}\), the volume of precipitate decreases leaving behind a white gelatinous precipitate. Identify the precipitate which dissolves in \(\mathrm{NH}_{4} \mathrm{OH} / \mathrm{NH}_{4} \mathrm{Cl}\) (a) \(\mathrm{Zn}(\mathrm{OH})_{2}\) (b) \(\mathrm{Al}(\mathrm{OH})_{3}\) (c) \(\mathrm{Mg}(\mathrm{OH})_{2}\) (d) \(\mathrm{Ca}(\mathrm{OH})_{2}\)

Two ores of the same metal \((\mathrm{M})\) are \(\left(\mathrm{A}_{1}\right)\) and \(\left(\mathrm{A}_{2}\right)\) (1) \(\mathrm{A}_{1} \stackrel{\text { calcination }}{\longrightarrow}\) Black residue \(\mathrm{C}+\mathrm{CO}_{2}+\mathrm{H}_{2} \mathrm{O}\) (2) \(\mathrm{A}_{1} \stackrel{\mathrm{HCl}, \mathrm{Kl}}{\longrightarrow} \mathrm{I}_{2}+\mathrm{D}\) precipitate (3) \(\mathrm{A}_{2} \stackrel{\text { roasting }}{\longrightarrow} \operatorname{Gas}(\mathrm{G})+\operatorname{Metal}(\mathrm{M})\) (4) \(\mathrm{G} \stackrel{+\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}, \text { acidified }}{\longrightarrow}\) Green solution Identify \(\mathrm{A}_{1}\) and \(\mathrm{A}\), here? (a) \(\mathrm{A}_{1}=\mathrm{CuCO}_{3} . \mathrm{Cu}(\mathrm{OH})_{2}, \mathrm{~A}_{2}=\mathrm{Cu}_{2} \mathrm{~S}\) (b) \(\mathrm{A}_{1}=\mathrm{Cu}_{2} \mathrm{~S}, \mathrm{~A}_{2}=\mathrm{CuCO}_{3} \cdot \mathrm{Cu}(\mathrm{OH})_{2}\) (c) \(\mathrm{A}_{1}=\mathrm{CuFeS}_{2}, \mathrm{~A}_{2}=\mathrm{Cu}_{2} \mathrm{~S}\) (d) none of these

Which compound is formed when excess of \(\mathrm{KCN}\) is added to an aqueous solution of copper sulphate? (a) \(\mathrm{Cu}(\mathrm{CN})\), (b) \(\mathrm{K}_{2}\left[\mathrm{Cu}(\mathrm{CN})_{6}\right]\) (c) \(\mathrm{K}\left[\mathrm{Cu}(\mathrm{CN})_{2}\right]\) (d) \(\mathrm{K}_{3}\left[\mathrm{Cu}(\mathrm{CN})_{4}\right]\)

A is a coloured crystalline solid which is easily soluble in water. Addition of aqueous KCN gives a precipitate which dissolves in excess of reagent whereas addition of KI aqueous solution gives a white grey precipitate with the liberation of iodine. On gently heating, A loses \(80 \%\) of its water of crystallization. Identify A here? (a) \(\mathrm{ZnSO}_{4} .7 \mathrm{H}_{2} \mathrm{O}\) (b) \(\mathrm{FeSO}_{4} \cdot 7 \mathrm{H}_{2} \mathrm{O}\) (c) \(\mathrm{CuSO}_{4} \cdot 5 \mathrm{H}_{2} \mathrm{O}\) (d) \(\mathrm{Hg}_{2} \mathrm{Cl}_{2}\)

Which of the following alloys contain Cu and \(\mathrm{Zn}\) ? 1\. bronze \(\quad\) 2. brass 3\. gun metal 4\. type metal (a) \(2,3,4\) (b) \(1,2,3\) (c) 1,2 (d) all

A white, water insoluble solid A turns yellow on heating and becomes white on cooling. A gives a clear solution B when treated with dilute \(\mathrm{HCl}\) or \(\mathrm{NaOH}\). When \(\mathrm{H}_{2} \mathrm{~S}\) is passed through solution \(\mathrm{B}\), and made neutral, a white precipitate \(\mathrm{C}\) is formed. Identify \(\mathrm{A} ?\) (a) \(\mathrm{ZnO}\) (b) \(\mathrm{CuO}\) (c) \(\mathrm{Fe}_{2} \mathrm{O}_{3}\) (d) \(\mathrm{Ag}_{2} \mathrm{O}\)

Match the following: List-I List-II 1\. Bell metal (i) \(\mathrm{Cu}: 60 \%-80 \%, \mathrm{Zn}: 20 \%-40 \%\) 2\. Gun metal (ii) Cu: \(75 \%-90 \%\), Sn: \(10 \%-25 \%\) 3\. Bronze (iii) \(\mathrm{Cu}: 88 \%, \mathrm{Sn}: 10 \%, \mathrm{Zn}: 2 \%\) 4\. Brass (iv) Cu: \(80 \%\) Sn: \(20 \%\) The correct matching is: \(\begin{array}{llll}1 & 2 & 3 & 4\end{array}\) (a) (iv) (iii) (ii) (i) (b) (iii) (iv) (ii) (i) (c) (iv) (ii) (i) (iii) (d) (iii) (iv) (i) (ii)

Which of the following statement is correct with reference to the ferrous and ferric ions? 1\. \(\mathrm{Fe}^{3+}\) gives brown colour with potassium ferricyanide 2\. \(\mathrm{Fe}^{2+}\) gives blue precipitate with potassium ferricyanide 3\. \(\mathrm{Fe}^{3+}\) gives red colour with potassium thiocyanate 4\. \(\mathrm{Fe}^{2+}\) gives brown colour with ammonium thiocyanate. (a) 1,4 (b) 1,2 (c) 2,3 (d) all of these

A colourless water soluble salt \(\mathrm{X}\) on heating gives brown gas and leaves a metallic residue. Solution of \(\mathrm{X}\) gives brick red precipitate with solution of \(\mathrm{K}_{2} \mathrm{CrO}_{4}\). An ammonical solution of \(\mathrm{X}\) gives a silver mirror with formic acid. Salt \(\mathrm{X}\) is used in making indelible election ink. Identify the salt \(X\) here? (a) \(\mathrm{AgCl}\) (b) \(\mathrm{HgNO}_{3}\) (c) \(\mathrm{AgNO}_{3}\) (d) \(\mathrm{Cu}\left(\mathrm{NO}_{3}\right)_{2}\)

Match the following: List-I 1\. Nichrome 2\. Type metal 3\. Wood's metal 4\. Devarda's alloy List-II (i) \(\mathrm{Pb}, \mathrm{Bi}, \mathrm{Sn}, \mathrm{Cd}\) (ii) \(\mathrm{Pb}, \mathrm{Sb}, \mathrm{Sn}\) (iii) \(\mathrm{Cu}, \mathrm{Al}, \mathrm{Zn}\) (iv) \(\mathrm{Fe}, \mathrm{Ni}, \mathrm{Cr}\) The correct matching is \(\begin{array}{llll}1 & 2 & 3 & 4\end{array}\) (a) (ii) (i) (iii) (iv) (b) (iii) (iv) (ii) (i) (c) (iv) (ii) (i) (iii) (d) (iii) (iv) (i) (ii)

In the process of extraction of gold roasted gold ore \(+\mathrm{CN}^{-}+\mathrm{H}_{2} \mathrm{O} \stackrel{\mathrm{O}_{2}}{\rightarrow}[\mathrm{X}]+\mathrm{OH}^{-}\) \([\mathrm{X}]+\mathrm{Zn} \longrightarrow[\mathrm{Y}]+\mathrm{Au}\) \([\mathrm{X}]\) and \([\mathrm{Y}]\) are (a) \([\mathrm{X}]=\left[\mathrm{Au}(\mathrm{CN})_{2}\right]^{-},[\mathrm{Y}]=\left[\mathrm{Zn}(\mathrm{CN})_{4}\right]^{-2}\) (b) \([\mathrm{X}]=\left[\mathrm{Au}(\mathrm{CN})_{4}\right]^{-3},[\mathrm{Y}]=\left[\mathrm{Zn}(\mathrm{CN})_{4}\right]^{-2}\) (c) \([\mathrm{X}]=\left[\mathrm{Au}(\mathrm{CN})_{2}\right],[\mathrm{Y}]=\left[\mathrm{Zn}(\mathrm{CN})_{6}\right]^{-4}\) (d) \([\mathrm{X}]=\left[\mathrm{Au}(\mathrm{CN})_{4}\right],[\mathrm{Y}]=\left[\mathrm{Zn}(\mathrm{CN})_{4}\right]^{-2}\)

Which of the following elements occur as their chlorides in earth crust ? (a) Na (b) \(\mathrm{Cu}\) (c) \(\mathrm{Ag}\) (d) \(\mathrm{K}\)

During the electrolysis of alumina, the functions of cryolite are (a) To increase conductivity of molten alumina (b) To decrease melting point of alumina (c) To eliminate the imputities from alumina (d) To increase anode effect.

Roasting of copper pyrites is done (a) To oxidize free sulphur (b) Ro remove moisture (c) To remove volatile organic impurities (d) To decompose sulphides into oxides.

Which of the following statements is/are correct for electrolytic refining? (a) The electric current used is AC (b) On account of electrolysis, the metal is indirectly transferred from anode to cathode (c) The impurity metal is made the anode while a thin sheet of pure metal is used as the cathode (d) The electrolyte used is a covalent compound of metal

Silver is a soft metal. It is hardened by alloying it with small amounts of (a) \(\mathrm{Cu}\) (b) \(\mathrm{Fe}\) (c) \(\mathrm{Ni}\) (d) \(\mathrm{Sn}\)

Which of the following are correctly matched? (a) Zone refining - Ultra pure Ge (b) Leaching - Extraction of \(\mathrm{Au}, \mathrm{Ag}\) (c) Cyanide process - Extraction of Au (d) Electrolyte reduction - Extraction of Al

In which of the following pair (s), the minerals are converted into metals by self reduction? (a) \(\mathrm{Cu}_{2} \mathrm{~S}, \mathrm{HgS}\) (b) \(\mathrm{Ag}_{2} \mathrm{~S}, \mathrm{ZnS}\) (c) \(\mathrm{PbS}, \mathrm{ZnS}\) (d) \(\mathrm{Cu}_{2} \mathrm{~S}, \mathrm{PbS}\)

Which of the following is/are oxide ore (s)? (a) Bauxite (b) Cassiterite (c) Haematite (d) Cryolite

The following methods are not advisable to extract zinc from its oxide ore. (a) Reduction with aluminium (b) Reduction with \(\mathrm{H}_{2}\) (c) Electrolytic reduction (d) Reduction with carbon

In the process of extraction of gold Roasted gold ore \(+\mathrm{CN}^{-}+\mathrm{H}_{2} \mathrm{O} \stackrel{\mathrm{O}_{\longrightarrow}}{\longrightarrow}[\mathrm{X}]+\mathrm{OH}^{-}\) \([\mathrm{X}]+\mathrm{Zn} \longrightarrow[\mathrm{Y}]+\mathrm{Au}\) Identify the complexes of \([\mathrm{X}]\) and [Y] (a) \(\mathrm{Y}=\left[\mathrm{Zn}(\mathrm{CN})_{4}\right]^{2-}\) (b) \(\mathrm{X}=\left[\mathrm{Au}(\mathrm{CN})_{4}\right]^{3-}\) (c) \(\mathrm{X}=\left[\mathrm{Au}(\mathrm{CN})_{2}\right]^{-}\) (d) \(\mathrm{Y}=\left[\mathrm{Zn}(\mathrm{CN})_{6}\right]^{4-}\)

The method of thermal decomposition cannot be used for (a) \(\mathrm{Au}\) (b) \(\mathrm{Hg}\) (c) \(\mathrm{Mg}\) (d) \(\mathrm{Ag}\)

Match the following Column-I (a) \(\mathrm{Ag}\) (b) \(\mathrm{Cu}\) (c) \(\mathrm{Zr}\) (d) \(\mathrm{Ni}\) Column-II (p) Froth flotation (q) Electrorefining (r) Van Arkel process (s) Mond's process (t) Hydrometallurgy

Match the following Column-I (a) \(\mathrm{Al}\) (b) \(\mathrm{Cu}\) (c) \(\mathrm{Mg}\) (d) \(\mathrm{Zn}\) Column-II (p) Calamine (q) Cryolite (r) Malachite (s) Carnallite (t) Magnesite

Match the following Column-I (a) Asbestos (b) Willemite (c) Anglesite (d) Diaspore Column-II (p) Calcium (q) Lead (r) Silicate (s) Aluminium (t) Sulphate

The number of sulphide minerals of the following is Cuprite, Argentite, Carnallite, Magnesite, Galena, Black Jack.

Among the metals, \(\mathrm{Ti}, \mathrm{V}, \mathrm{W}, \mathrm{Zr}, \mathrm{Th}\) and \(\mathrm{Au}\), the no. of metals purified by van Arkel method is

Among the following minerals, siderite, malachite, cerussite, anglessite, smithsonite, diaspore, mica and corundum, the number of carbonate minerals is

Among \(\mathrm{Zn}, \mathrm{Cd}, \mathrm{Cu}, \mathrm{Sn}, \mathrm{Ge}, \mathrm{Pb}, \mathrm{Au}\) and \(\mathrm{Bi}\), no. of metals refined by liquation is

When the sample of copper with zinc impurity is to be purified by electrolysis the appropriate electrodes are [2002] Cathode \(\quad\) Anode \(\begin{array}{ll}\text { (a) pure zinc } & \text { pure copper }\end{array}\) (b) pure copper impure sample (c) impure zinc impure sample (d) impure sample pure copper

For making good quality mirrors, plates of float glass are used. These are obtained by floating molten glass over a liquid metal which does not solidify before glass. The metal used can be (a) mercury (b) tin (c) sodium (d) magnesium

Which one of the following nitrates will leave behind a metal on strong heating? (a) ferric nitrate (b) copper nitrate (c) manganese nitrate (d) silver nitrate