Chapter 19

In nitroprusside ion, the iron and NO exist as \(\mathrm{Fe}^{\mathrm{ll}}\) and \(\mathrm{NO}^{+}\)rather than \(\mathrm{Fe}^{\mathrm{lH}}\) and NO. These forms can be differentiated by (a) estimating the concentration of iron (b) measuring the concentration of \(\mathrm{CN}^{-}\) (c) measuring the solid state magnetic moment (d) thermally decomposing the compound

Which of the following compounds is expected to be coloured? (a) \(\mathrm{Ag}_{2} \mathrm{SO}_{4}\) (b) \(\mathrm{CuF}_{2}\) (c) \(\mathrm{MgF}_{2}\) (d) \(\mathrm{CuCl}\)

The aqueous solution of the following salts will be coloured in the case of (a) \(\mathrm{Zn}\left(\mathrm{NO}_{3}\right)_{2}\) (b) \(\mathrm{LiNO}_{3}\) (c) \(\mathrm{Co}\left(\mathrm{NO}_{3}\right)_{2}\) (d) potash alum

The correct ground state electronic configuration for the atom \((\mathrm{Z}=24)\) is (a) \([\mathrm{Ar}] 3 \mathrm{~d}^{5} 4 \mathrm{~s}^{1}\) (b) \([\mathrm{Ar}] 3 \mathrm{~d}^{4} 4 \mathrm{~s}^{2}\) (c) \([\mathrm{Ar}] 3 \mathrm{~d}^{6} 4 \mathrm{~s}^{\circ}\) (d) \([\mathrm{Ar}] 3 \mathrm{~d}^{5} 4 \mathrm{~s}^{2}\)

How many unpaired electrons are present in \(\mathrm{Ni}^{2+}\) ? (a) 8 (b) 4 (c) 2 (d) 0

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

The pair of which salts is expected to have the same colour in their freshly prepared aqueous solutions. (a) \(\mathrm{VOCl}_{2}, \mathrm{CuCl}_{2}\) (b) \(\mathrm{CuCl}_{2}, \mathrm{FeCl}_{2}\) (c) \(\mathrm{FeCl}_{2}, \mathrm{VOCl}_{2}\) (d) \(\mathrm{MnCl}_{2}, \mathrm{FeCl}_{2}\)

When sodium argentocyanide is treated with zinc dust, silver precipitates because (a) zinc forms a complex readily with cyanide (b) zinc is more electropositive than silver (c) silver is more electropositive than zinc (d) both \(\mathrm{Zn}^{2+}\) and \(\mathrm{Ag}^{+}\)ions have \(\mathrm{d}^{10}\) electronic configuration

Which one of the following metals will not reduce \(\mathrm{H}_{2} \mathrm{O} ?\) (a) Li (b) \(\mathrm{Fe}\) (c) \(\mathrm{Cu}\) (d) \(\mathrm{Ca}\)

In which one of the following transition metal complexes, does the metal exhibit zero oxidation state? (a) \(\left[\mathrm{Ni}(\mathrm{CO})_{4}\right]\) (b) \(\left[\mathrm{Fe}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right] \mathrm{X}_{3}\) (c) \(\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{6}\right] \mathrm{Cl}_{3}\) (d) \(\left[\mathrm{Fe}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right] \mathrm{SO}_{4}\)

Which statement is not correct? (a) \(\mathrm{La}(\mathrm{OH})_{3}\) is less basic than \(\mathrm{Lu}(\mathrm{OH})_{3}\) (b) in lanthanide series, ionic radius of \(\mathrm{Ln}^{3+}\) ions decreases (c) La is actually an element of transition series (d) atomic radius of \(\mathrm{Zn}\) and Hf are same because of lanthanide contraction

Which compound is coloured due to charge transfer spectra and not due to d-d transitions? (a) \(\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}\) (b) \(\mathrm{KMnO}_{4}\) (c) \(\mathrm{CrO}_{3}\) (d) All of these

Colour in transition metal compounds is attributed to (a) small size metal ions (b) absorption of light in uv region (c) complete ( \(\mathrm{n}, \mathrm{s}\) ) subshell (d) incomplete (n-1)d subshell

A solution, when diluted with \(\mathrm{H}_{2} \mathrm{O}\) and boiled, gives a white precipitate. On addition of excess of \(\mathrm{NH}_{4} \mathrm{Cl} /\) \(\mathrm{NH}_{4} \mathrm{OH}\), 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) \(\mathrm{Ca}(\mathrm{OH})_{2}\)

\(\mathrm{CuSO}_{4}\) decolourizes on addition of 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) \(\mathrm{CuCN}\)

If the bond length of \(\mathrm{CO}\) bond in carbon monoxide is \(1.128 \AA\), then what is the value of \(\mathrm{CO}\) bond length in \(\mathrm{Fe}(\mathrm{CO})_{5} ?\) (a) \(1.15 \AA\) (b) \(1.128 \AA\) (c) \(1.72 \AA\) (d) \(1.118 \AA\)

The pair of the compounds in which both the metals are in the highest possible oxidation state is (a) \(\left[\mathrm{Co}(\mathrm{CN})_{6}\right]^{3-}, \mathrm{MnO}_{2}\) (b) \(\mathrm{CrO}_{2} \mathrm{Cl}_{2}, \mathrm{MnO}_{4}^{-}\) (c) \(\mathrm{TiO}_{3}, \mathrm{MnO}_{2}\) (d) \(\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]^{3-},\left[\mathrm{Co}(\mathrm{CN})_{6}\right]^{3-}\)

The product formed on oxidation of \(\mathrm{I}^{-}\)with \(\mathrm{MnO}_{4}^{-}\)in alkaline medium is (a) \(\mathrm{IO}_{4}^{-}\) (b) \(\mathrm{I}_{2}\) (c) IO (d) \(\mathrm{IO}_{3}^{-}\)

An aqueous solution of \(\left[\mathrm{Ti}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{3+}\) ion has a mild violet colour of low intensity. Which of the following statements is incorrect? (a) The colour results from an electronic transition of one electron from the \(t_{2}\) to an \(\mathrm{e}_{e}\) orbital (b) The ion absorbs visible light in the region of \(\sim 5000 \AA\) (c) The transition is the result of metal-ligand back bonding (d) The low colour intensity is because of a low probability of transition

When \(\mathrm{MnO}_{2}\) is fused with KOH, a coloured compound is formed. The product and its colour is (a) \(\mathrm{K}_{2} \mathrm{MnO}_{4}\), purple green (b) \(\mathrm{KMnO}_{4}\), purple (c) \(\mathrm{Mn}_{2} \mathrm{O}_{3}\), brown (d) \(\mathrm{Mn}_{3} \mathrm{O}_{4}\), black

In the process of extraction of gold, roasted gold ore \(+\mathrm{CN}^{-}+\mathrm{H}_{2} \mathrm{O} \stackrel{\mathrm{O}_{2}}{\longrightarrow}[\mathrm{X}]+[\mathrm{Y}]+\mathrm{Zn}\) \(+\mathrm{Au},[\mathrm{X}]\) 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) \([\mathrm{X}]=\left[\mathrm{Au}(\mathrm{CN})_{4}\right]^{-},[\mathrm{Y}]=\left[\mathrm{Zn}(\mathrm{CN})_{4}\right]^{-2}\)

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

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

Which of the following statement is correct when a mixture of \(\mathrm{NaCl}\) and \(\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}\) is gently warmed with concentrated \(\mathrm{H}_{2} \mathrm{SO}_{4} ?\) 1\. deep red coloured vapours are evolved 2\. the vapours when passed into \(\mathrm{NaOH}\) solution give a yellow solution of \(\mathrm{Na}_{2} \mathrm{CrO}_{4}\) 3\. chlorine gas is evolved 4\. chromyl chloride is formed (a) \(1,2,4\) (b) \(1,2,3\) (c) \(2,3,4\) (d) all are correct

Which of the following has the maximum number of unpaired electrons? (a) \(\mathrm{Mg}^{2+}\) (b) \(\mathrm{Ti}^{3+}\) (c) \(\mathrm{V}^{3+}\) (d) \(\mathrm{Fe}^{2+}\)

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

The elements which exist in the liquid state at room temperature are 1\. Na 2\. Br 3\. \(\mathrm{Hg}\) 4\. Ga (a) \(1,2,3\) (b) 2,3 (c) 2,4 (d) \(1,2,3\)

The equivalent weight of \(\mathrm{MnSO}_{4}\) is half of its molecular weight, when it is converted to (a) \(\mathrm{Mn}_{2} \mathrm{O}_{3}\) (b) \(\mathrm{MnO}_{2}\) (c) \(\mathrm{MnO}_{4}^{-}\) (d) \(\mathrm{MnO}_{4}^{2-}\)

Which among the following paramagnetic pairs rare? (1) \(\left[\mathrm{BaO}_{2}, \mathrm{NO}_{2}\right]\) (2) \(\left[\mathrm{KO}_{2}, \mathrm{NO}\right]\) (3) \(\left[\mathrm{H}_{2} \mathrm{O}_{2}, \mathrm{NO}\right]\) (4) \(\left[\mathrm{K}_{3} \mathrm{Fe}(\mathrm{CN})_{6}, \mathrm{CuCl}_{2}\right]\) (a) 3,4 only (b) 1,3 only (c) 2,4 only (d) \(1,2,4\)

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) \(\mathrm{CuSO}_{4} \cdot 5 \mathrm{H}_{2} \mathrm{O}\) (c) \(\mathrm{FeSO}_{4} \cdot 6 \mathrm{H}_{2} \mathrm{O}\) (d) \(\mathrm{NiSO}_{4} \cdot 6 \mathrm{H}_{2} \mathrm{O}\)

A brown ring complex compound is formulated as \(\left[\mathrm{Fe}\left(\mathrm{H}_{2} \mathrm{O}\right)_{3} \mathrm{NO}^{+}\right] \mathrm{SO}_{4}\). The oxidation state of iron here is (a) 1 (b) 2 (c) 3 (d) 4

In the metallurgy of iron, when limestone is added to the blast furnace, the calcium ions end up in (a) gangue (b) calcium carbonate (c) slag (d) metallic calcium

Iron is rendered passive by treatment with concentrated (a) \(\mathrm{HCl}\) (b) \(\mathrm{HNO}_{3}\) (c) \(\mathrm{H}_{3} \mathrm{PO}_{4}\) (d) \(\mathrm{H}_{2} \mathrm{SO}_{4}\)

Sodium thiosulphate is used in photography because of its (a) reaction with light (b) oxidizing behaviour (c) reducing behaviour (d) complex forming behaviour

Match the following: List I (n = un-paired e \(\mathbf{~}^{-}\)) \(\quad\) List II (Meg. moment) 1\. \(\mathrm{Sc}^{3+}=0\) (i) 5.92 B.M. 2\. \(\mathrm{V}^{2+}=3\) (ii) \(1.73\) B.M. 3\. \(\mathrm{Fe}^{3+}=5\) (iii) zero 4\. \(\mathrm{Cu}^{2+}=1\) (iv) \(3.87\) B.M. The correct matching is: \(\begin{array}{llll}1 & 2 & 3 & 4\end{array}\) (a) (ii) (i) (iii) (iv) (b) (iii) (iv) (ii) (i)

A blue colouration is obtained in which case? (1) on dissolving \(\mathrm{NH}_{4} \mathrm{OH}\) in copper sulphate. (2) on reacting \(\mathrm{CuSO}_{4}\) solution with potassium ferrocyanide. (3) on reacting \(\mathrm{FeCl}_{3}\) with sodium ferrocyanide. (4) on dissolving anhydrous \(\mathrm{CuSO}_{4}\) in water. (a) 2,4 only (b) \(1,3,4\) (c) \(1,2,4\) (d) 3,4 only

Which of the following is/are characteristics of d-block elements? (a) They are generally diamagnetic (b) They form coloured complexes (c) They show variable oxidation states (d) Their ionization energies are very high

Which of the following metals have both valence shell and penultimate shell partially filled? (a) \(\mathrm{Cu}\) (b) \(\mathrm{Zn}\) (c) \(\mathrm{Cr}\) (d) \(\mathrm{Mn}\)

Which of the following d-block elements do not posses characteristics properties of transition elements? (a) Cadmium (b) Manganese (c) Zinc (d) Copper

Which of the following compounds are coloured due to charge transfer spectra? (a) \(\mathrm{AgNO}_{3}\) (b) \(\mathrm{CuSO}_{4}\) (c) \(\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}\) (d) \(\mathrm{KMnO}_{4}\)

The mixture of which of the following can produce blue colouration? (a) Iron (III) chloride and \(\mathrm{K}_{4}\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]\) (aq) (b) \(\mathrm{NH}_{4} \mathrm{OH}\) (aq) and \(\mathrm{CuSO}_{4}\) (aq) (c) Adding anhydrous \(\mathrm{CuSO}_{4}\) to water (d) \(\mathrm{ZnCl}_{2}\) (aq) and \(\mathrm{K}\left[\mathrm{Fe}(\mathrm{CN})_{6}\right](\mathrm{aq})\)

Which of the following conditions is/are suitable for the stability of the complex? (a) Chelation (b) Larger basic nature of the ligand (c) Larger charge on the central metal ion. (d) Smaller charge on the central metal ion

The transition elements with some exceptions can show a large number of oxidation states. The various oxidation states are related to the electronic configuration of their atoms. The variable oxidation states of a transition metal is due to the involvement of \((\mathrm{n}-1) \mathrm{d}\) and outer \(\mathrm{ns}\)-electrons. For the first five elements of 3 d-transition series. The minimum oxidation state is equal to the number of electrons in 4s shell and the maximum oxidation state is equal to the sum of \(4 \mathrm{~s}\) and \(3 \mathrm{~d}\)-electrons. The relative stability of various oxidation state of a given element can be explained on the basis of stability of \(\mathrm{d}^{0}, \mathrm{~d}^{5}\) and \(\mathrm{d}^{10}\) configurations. In 3 d-series, the maximum oxidation state is shown by (a) \(\mathrm{Fe}(26)\) (b) Mn (atomic no.: 25 ) (c) \(\mathrm{Cr}(24)\) (d) Sc (atomic no: 21 )

The transition elements with some exceptions can show a large number of oxidation states. The various oxidation states are related to the electronic configuration of their atoms. The variable oxidation states of a transition metal is due to the involvement of \((\mathrm{n}-1) \mathrm{d}\) and outer \(\mathrm{ns}\)-electrons. For the first five elements of 3 d-transition series. The minimum oxidation state is equal to the number of electrons in 4s shell and the maximum oxidation state is equal to the sum of \(4 \mathrm{~s}\) and \(3 \mathrm{~d}\)-electrons. The relative stability of various oxidation state of a given element can be explained on the basis of stability of \(\mathrm{d}^{0}, \mathrm{~d}^{5}\) and \(\mathrm{d}^{10}\) configurations. In which of the following pair, the first species is more stable than second one (a) \(\mathrm{Mn}^{2+}, \mathrm{Mn}^{3+}\) (b) \(\mathrm{Sc}^{2+}, \mathrm{Sc}^{3+}\) (c) \(\mathrm{Ti}^{3+}, \mathrm{Ti}^{4+}\) (d) \(\mathrm{Fe}^{2+}, \mathrm{Fe}^{3+}\)

The transition elements with some exceptions can show a large number of oxidation states. The various oxidation states are related to the electronic configuration of their atoms. The variable oxidation states of a transition metal is due to the involvement of \((\mathrm{n}-1) \mathrm{d}\) and outer \(\mathrm{ns}\)-electrons. For the first five elements of 3 d-transition series. The minimum oxidation state is equal to the number of electrons in 4s shell and the maximum oxidation state is equal to the sum of \(4 \mathrm{~s}\) and \(3 \mathrm{~d}\)-electrons. The relative stability of various oxidation state of a given element can be explained on the basis of stability of \(\mathrm{d}^{0}, \mathrm{~d}^{5}\) and \(\mathrm{d}^{10}\) configurations. Identify the correct statement (a) \(\mathrm{Ti}^{4+}, \mathrm{Mn}^{2+}\) are stable oxidation states (b) The most common oxidation state of 3 d-series is \(+2\) (c) The lowest oxidation state of \(\mathrm{Cr}\) and \(\mathrm{Cu}\) is \(+1\) while for others it is \(+2\). (d) All of these

The d-orbitals participating in hybridization of central metal atom may be from the outermost shell or the penultimate shell. This depends on the nature of metal and the nature of ligand. The complexes involving the inner \(\mathrm{d}\) level (inner orbital complexes) result when the ligand is a powerful or strong ligand resulting in diamagnetic or low spin complexes. A weak ligand usually results in the formation of outer orbital complex or high spin complex. The hybridization of \(\mathrm{Cu}\) in \(\left[\mathrm{CuCl}_{4}\right]^{2-}\) and \(\left[\mathrm{Cu}\left(\mathrm{NH}_{3}\right)_{4}\right]^{2+}\) are respectively. (a) \(\mathrm{sp}^{3}, \mathrm{dsp}^{2}\) (b) \(\mathrm{dsp}^{2}, \mathrm{dsp}^{2}\) (c) \(\mathrm{dsp}^{2}, \mathrm{sp}^{3}\) (d) \(\mathrm{sp}^{3}, \mathrm{sp}^{3}\)

The d-orbitals participating in hybridization of central metal atom may be from the outermost shell or the penultimate shell. This depends on the nature of metal and the nature of ligand. The complexes involving the inner \(\mathrm{d}\) level (inner orbital complexes) result when the ligand is a powerful or strong ligand resulting in diamagnetic or low spin complexes. A weak ligand usually results in the formation of outer orbital complex or high spin complex. The number of unpaired electrons present in \(\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]^{4-}\) and \(\left[\mathrm{Fe}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}\) are, respectively (a) 0,0 (b) 0,4 (c) 1,2 (d) 2,4

The number of unpaired electrons present in \(\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]^{4-}\) and \(\left[\mathrm{Fe}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}\) are, respectively (a) 0,0 (b) 0,4 (c) 1,2 (d) 2,4Among the following four sets, the one having the same geometry and same magnetic property for both complexes is (a) \(\left[\mathrm{Co}\left(\mathrm{CN}_{6}\right)\right]^{3-}\) and \(\left[\mathrm{CoF}_{6}\right]^{3-}\) (b) \(\left[\mathrm{Mn}(\mathrm{CN})_{6}\right]^{3-}\) and \(\left[\mathrm{MnF}_{6}\right]^{3-}\) (c) \([\mathrm{Cr}(\mathrm{CN})]^{3-}\) and \(\left[\mathrm{Cr}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{3+}\) (d) \(\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]^{4-}\) and \(\left[\mathrm{Fe}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}\)

Match the following $$ \begin{array}{ll} \text { List-I } & \text { List-II } \\ \hline \text { (a) Highest density } & \text { (p) } \mathrm{Os} \\ \text { (b) Colourless salts } & \text { (q) } \mathrm{Cr} \\ \text { (c) Maximum magnetic } & \text { (r) } \mathrm{Zn} \\ \text { moment } & \\ \text { (d) Variable oxidation state } & \text { (s) } \mathrm{Mn} \end{array} $$

Match the following $$ \begin{aligned} &\begin{array}{ll} \text { List-I } & \text { List-II } \\ \hline \text { (a) Coloured ion } & \text { (p) } \mathrm{Cu}^{+} \\ \text {(b) } \mu=1.73 \mathrm{~B} \cdot \mathrm{M} & \text { (q) } \mathrm{Cu}^{2+} \\ \text { (c) } \mathrm{d}^{10} \text { configuration } & \text { (r) } \mathrm{Fe}^{2+} \\ \text { (d) } \begin{array}{l} \text { More than } 3 \text { un-paired } \\ \text { electrons } \end{array} & \text { (s) } \mathrm{Mn}^{2+} \\ \hline \end{array}\\\ &\text { - } \end{aligned} $$