Chapter 19

Which statement is not correct with respect to transition metals? (a) the colour of the hydrated ions is due to transitions of electrons from different 'd' orbitals of the same principal quantum number (b) most transition metals should, on thermodynamic considerations, liberate hydrogen from acids (c) the complex formation of transition metal ions is often accompanied by a change of colour and sometimes by a change in the intensity of the colour (d) the compounds of the elements in low oxidation states are generally ionic

Which of the following statements is not correct? (a) in oxyhaemoglobin, \(\mathrm{Fe}^{2+}\) is paramagnetic. (b) during respiration, the size of \(\mathrm{Fe}^{2+}\) increases when it changes from diamagnetic to paramagnetic state. (c) four heme groups are present in haemoglobin. (d) heme is the prosthetic group and it is non protein part of haemoglobin.

The pair in which both species have the same magnetic moment (spin only value) is (a) \(\left[\mathrm{Cr}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+},\left[\mathrm{CoCl}_{4}\right]^{2-}\) (b) \(\left[\mathrm{Cr}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+},\left[\mathrm{Fe}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}\) (c) \(\left[\mathrm{Mn}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+},\left[\mathrm{Cr}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}\) (d) \(\left[\mathrm{CoCl}_{4}\right]^{2-},\left[\mathrm{Fe}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}\)

Transition metals despite having higher values of standard reduction potentials, are poor reducing agents. This is due to (a) low heat of hydration (b) high ionization energies (c) low ionization energies (d) high enthalpy of vapourization

The pair in which both species have iron is (a) nitrogenase, cytochromes (b) carboxypeptidase, haemoglobin (c) haemocyanin, nitrogenase (d) haemoglobin cytochromes

In nitroprusside ion, the iron and NO exist as \(\mathrm{Fe}^{\mathrm{ll}}\) and NO \(^{+}\)rather than \(\mathrm{Fe}^{\mathrm{II}}\) 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

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 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

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) \(\mathrm{CuCl}_{2}^{2}, \mathrm{FeCl}_{2}\) (c) \(\mathrm{FeCl}_{2}, \mathrm{VOCl}_{2}\) (d) \(\mathrm{MnCl}_{2}, \mathrm{FeCl}_{2}^{2}\)

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) \(\mathrm{Li}\) (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 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 (n, s) subshell (d) incomplete ( \(\mathrm{n}-1\) )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 \([\mathrm{Cu}(\mathrm{CN})]^{3-}\) (c) \(\mathrm{Cu}(\mathrm{CN})_{2}\) (d) \(\mathrm{CuCN}\)

\(\mathrm{CuSO}_{4}\) 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 \([\mathrm{Cu}(\mathrm{CN})]^{3-}\) (c) \(\mathrm{Cu}(\mathrm{CN})_{2}\) (d) \(\mathrm{CuCN}\)

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) \(\mathrm{CrO}_{2} \mathrm{Cl}_{2}, \mathrm{MnO}_{4}^{-}\)

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) \(\mathrm{CrO}_{2} \mathrm{Cl}_{2}, \mathrm{MnO}_{4}^{-}\)

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) \(\mathrm{IO}_{3}^{-}\)

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) \(\mathrm{Mn}_{i} \mathrm{O}_{4}\), black

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) \(\mathrm{Mn}_{i} \mathrm{O}_{4}\), 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) \(\mathrm{K}_{3}\left[\mathrm{Cu}(\mathrm{CN})_{4}\right]\)

One gram of impure \(\mathrm{K}_{2} \mathrm{CrO}_{4}\) was treated chemically, so as to convert all the chromium in it quantitatively into \(\mathrm{CrO}_{2} \mathrm{Cl}_{2}\), which was then hydrolyzed; the products of hydrolysis yielded 1 gram of precipitated \(\mathrm{AgCl}\) with sufficient \(\mathrm{AgNO}_{3}\) and dilute \(\mathrm{HNO}_{3} .\) Estimate the percentage of \(\mathrm{K}_{2} \mathrm{CrO}_{4}\) in the original sample of \(\mathrm{K}_{2} \mathrm{CrO}_{4} .\) (Atomic weight of \(\mathrm{Cr}=52\) ) (a) \(58 \%\) (b) \(68 \%\) (c) \(62 \%\) (d) \(47 \%\)

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) \(1,2,3\)

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

Match the following: List I List II 1\. \(\mathrm{Cu}^{2+}\) (i) colourless 2\. \(\mathrm{Ni}^{2+}\) (ii) green 3\. \(\mathrm{Fe}^{3+}\) (iii) yellow 4\. \(\mathrm{Ti}^{3+}\) (iv) blue (v) purple The correct matching is: \(1 \quad 2 \quad 3\) 4 (a) (i) (ii) (iii) (v) (b) (i) (iii) (ii) (iv) (c) (ii) (i) (iii) (v) (d) (iv) (ii) (iii) (v)

A brown ring complex compound is formulated as \(\left[\mathrm{Fe}\left(\mathrm{H}_{2} \mathrm{O}\right)_{5} \mathrm{NO}^{+}\right] \mathrm{SO}_{4}\). 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

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

Which of the following matching is/are correct here? (a) Secondary valencies - oxidation number (b) Primary valencies - hold ionisable species (c) Primary valencies - oxidation state (d) Secondary valencies -ordination number

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

In 3 d-series, the maximum oxidation state is shown by (a) \(\mathrm{Fe}(26)\) (b) Mn (atomic no. : 25 ) (c) \(\operatorname{Cr}(24)\) (d) Sc (atomic no: 21 )

In which of the following pair, the first species is more stable than second one (a) \(\mathrm{Mn}^{2+}, \mathrm{Mn}^{3+}\) (b) \(\mathrm{S} \mathrm{c}^{2+}, \mathrm{S} \mathrm{c}^{3+}\) (c) \(\mathrm{Ti}^{3+}, \mathrm{Ti}^{4+}\) (d) \(\mathrm{Fe}^{2+}, \mathrm{Fe}^{3+}\)

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 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) \(s p^{3}, s p^{3}\)