Chapter 34

A green crystalline compound shows the following tests: (i) Its aqueous solution gives a dense white precipitate with Barium chloride solution (ii) Its aqueous solution gives a rose-red precipitate with dimethyl glyoxime and \(\mathrm{NH}_{4} \mathrm{OH}\). The compound is (a) \(\mathrm{NiSO}_{4}\) (b) \(\mathrm{FeSO}_{4}\) (c) \(\mathrm{Cr}_{2}\left(\mathrm{SO}_{4}\right)_{3}\) (d) \(\mathrm{FeCl}_{3}\)

\(\mathrm{K}_{3}\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]\) is used as the indicator in the \(\mathrm{Fe}^{2 \oplus}-\) \(\mathrm{Cr}_{2} \mathrm{O}_{7}^{2 \oplus}\) titration in acidic medium. The end point of the titration can be noted (a) By the appearance of colour of the titrated solution with the indicator (b) By the appearance of a transient blue colour after the end point (c) By failure of the indicator to give a colour with the titrated solution (d) By a sudden change of colour from deep blue to intense green at the end point.

\([\mathrm{X}]+\mathrm{H}_{2} \mathrm{SO}_{4} \rightarrow[\mathrm{Y}]\), a colourless gas with irritating smell. \([\mathrm{Y}]+\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}+\mathrm{H}_{2} \mathrm{SO}_{4} \rightarrow\) green solution. \([\mathrm{X}]\) and \([\mathrm{Y}]\) are (a) \(\mathrm{SO}_{3}^{-2}, \mathrm{SO}_{2}\) (b) \(\mathrm{Cl}^{-}, \mathrm{HCl}\) (c) \(\mathrm{S}^{-2}, \mathrm{H}_{2} \mathrm{~S}\) (d) \(\mathrm{CO}_{3}^{-2}, \mathrm{CO}_{2}\)

A gas ' \(\mathrm{X}\) ' is passed through water to form a saturated solution. The aqueous solution on treatment with the \(\mathrm{AgNO}_{3}\) gives a white precipitate. The saturated aqueous solution also dissolves magnesium ribbon with evolution of a colourless gas ' \(\mathrm{Y}^{\prime}\). Identify ' \(\mathrm{X}\) 'and ' \(\mathrm{Y}\) '. (a) \(\mathrm{X}=\mathrm{Cl}_{2}, \mathrm{Y}=\mathrm{H}_{2}\) (b) \(\mathrm{X}=\mathrm{H}_{2}, \mathrm{Y}=\mathrm{Cl}_{2}\) (c) \(\mathrm{X}=\mathrm{Cl}_{2}, \mathrm{Y}=\mathrm{CO}_{2}\) (d) \(\mathrm{X}=\mathrm{CO}_{2}, \mathrm{Y}=\mathrm{Cl}_{2}\)

In the titration of a certain solution of a mixture of \(\mathrm{NaHCO}_{3}\) and \(\mathrm{Na}_{2} \mathrm{CO}_{3}\) against \(\mathrm{HCl}, \mathrm{V}_{1} \mathrm{~mL}\) of \(\mathrm{HCl}\) is required with phenolphthalein as indicator and \(\mathrm{V}_{2} \mathrm{~mL}\) with methyl orange as indicator for the same volume of the titrated solution. Hence volume of HCl for reaction of \(\mathrm{HCl}\) with \(\mathrm{Na}_{2} \mathrm{CO}_{3}\) alone is (a) \(\mathrm{V}_{2} / 4 \mathrm{~mL}\) (b) \(2 \mathrm{~V}_{1} \mathrm{~mL}\) (c) \(\left(\mathrm{V}_{2}-\mathrm{V}_{1}\right) \mathrm{mL}\) (d) \(\left(\mathrm{V}_{1} / 3\right) \mathrm{mL}\)

Identify the products \(\mathrm{A}\) and \(\mathrm{B}\) here. (1) \(2 \mathrm{Ag}^{+}(\)excess \()+\mathrm{S}_{2} \mathrm{O}_{3}{\underline{\phantom{xx}}}^{2-} \longrightarrow \mathrm{Ag}_{2} \mathrm{~S}_{2} \mathrm{O}_{3}\) \(\stackrel{\mathrm{H}_{2} \mathrm{O}}{\longrightarrow} \mathrm{A}+\mathrm{H}_{2} \mathrm{SO}_{4}\) (2) \(2 \mathrm{NO}_{2}^{-}+2 \mathrm{I}^{-} \stackrel{\text { acid medium }}{\longrightarrow} \mathrm{B}+\mathrm{I}_{2}+2 \mathrm{H}_{2} \mathrm{O}\) (a) \(\mathrm{A}=\mathrm{Ag}_{2} \mathrm{O}, \mathrm{B}=\mathrm{N}_{2}\) (b) \(\mathrm{A}=\mathrm{Ag}_{2} \mathrm{~S}, \mathrm{~B}=\mathrm{N}_{2} \mathrm{O}\) (c) \(\mathrm{A}=\mathrm{Ag}_{2} \mathrm{O}, \mathrm{B}=2 \mathrm{NO}_{2}\) (d) \(\mathrm{A}=\mathrm{Ag}_{2} \mathrm{~S}, \mathrm{~B}=2 \mathrm{NO}\)

A solution of a metal ion when treated with KI gives a red precipitate which dissolves in excess KI to give a colourless solution. Moreover, the solution of metal ion on treatment with a solution of cobalt(II) thiocyanate gives rise to a deep blue crystalline precipitate. The metal ion is (a) \(\mathrm{Pb}^{2+}\) (b) \(\mathrm{Hg}^{2+}\) (c) \(\mathrm{Cu}^{2+}\) (d) \(\mathrm{Co}^{2+}\)

\(20 \mathrm{~mL}\) of \(0.1 \mathrm{M} \mathrm{NaOH}\) and \(30 \mathrm{~mL}\) of \(0.12 \mathrm{M} \mathrm{NaHCO}_{3}\) solutions are mixed. \(25 \mathrm{ml}\) of the resulting solution are titrated against \(0.1 \mathrm{M} \mathrm{HCl}\) using phenolphthalein as the indicator. What would be the titre value? (a) \(100 \mathrm{~mL}\) (b) \(10 \mathrm{~mL}\) (c) \(25 \mathrm{~mL}\) (d) \(20 \mathrm{~mL}\)

A solution, when diluted with \(\mathrm{H}_{2} \mathrm{O}\) 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) \(\mathrm{Ca}(\mathrm{OH})_{2}\)

When a solid substance is a mixture of \(\mathrm{KBr}\) and \(\mathrm{KNO}_{3} .\) Which of the following does not give a distinguishing test? (a) Adding \(\mathrm{AgNO}_{3}\) solution in presence of dilute \(\mathrm{HNO}_{3}\) to a solution of the mixture in water (b) Warming the mixture with concentrated \(\mathrm{H}_{2} \mathrm{SO}_{4}\) (c) Adding dilute \(\mathrm{H}_{2} \mathrm{SO}_{4}\) followed by drops of \(\mathrm{KMnO}_{4}\), to an aqueous solution of the substance, then adding \(\mathrm{CCl}_{4}\) and shaking (d) Adding chlorine water to an aqueous solution of the substance, followed by adding \(\mathrm{CCl}_{4}\) and shaking.

In the separation of \(\mathrm{Cu}^{2+}\) and \(\mathrm{Cd}^{2+}\) in 2 nd group qualitative analysis of cations, tetrammine copper (II) sulphate and tetrammine cadmium(II) sulphate react with \(\mathrm{KCN}\) to form the corresponding cyano complexes. Which one of the following pairs of the complexes and their relative stability enables the separation of \(\mathrm{Cu}^{2+}\) and \(\mathrm{Cd}^{2+}\) ? (a) \(\mathrm{K}_{2}\left[\mathrm{Cu}(\mathrm{CN})_{4}\right]\) less stable and \(\mathrm{K}_{2}\left[\mathrm{Cd}(\mathrm{CN})_{4}\right]\) more stable (b) \(\mathrm{K}_{3}\left[\mathrm{Cu}(\mathrm{CN})_{4}\right]\) more stable and \(\mathrm{K}_{2}\left[\mathrm{Cd}(\mathrm{CN})_{4}\right]\) less stable (c) \(\mathrm{K}_{3}\left[\mathrm{Cu}(\mathrm{CN})_{4}\right]\) less stable and \(\mathrm{K}_{2}\left[\mathrm{Cd}(\mathrm{CN})_{4}\right]\) more stable (d) \(\mathrm{K}_{2}\left[\mathrm{Cu}(\mathrm{CN})_{4}\right]\) more stable and \(\mathrm{K}_{2}\left[\mathrm{Cd}(\mathrm{CN})_{4}\right]\) less stable

A white substance, 'X' evolves on warming with ethanol and conc. \(\mathrm{H}_{2} \mathrm{SO}_{4}\), a vapour which burns with a green-edged flame. \(X\), when mixed with solid \(\mathrm{Na}_{2} \mathrm{CO}_{3}\) and heated on a cavity on charcoal gives a white luminous mass which, when moistened with a drop of \(\mathrm{Co}\left(\mathrm{NO}_{3}\right)_{2}\) solution and heated further yields a green mass. The substance, \(X\) is expected to be (a) \(\mathrm{ZnSO}_{4}\) (b) \(\mathrm{HgCl}_{2}\) (c) \(\mathrm{AlPO}_{4}\) (d) \(\mathrm{Zn}\left(\mathrm{BO}_{2}\right)_{2}\)

Pick out the correct statement(s) here: (1) Golden yellow \(\mathrm{PbI}_{2}\) dissolves in hot water to give a colourless solution. (2) \(\mathrm{Ba}^{2+}\) and \(\mathrm{Ca}^{2+}\) ions can be separated by adding \(\mathrm{CrO}_{4}^{2-}\) ion in acetic acid medium (3) Salts of calcium, copper and nickel give a green flame colour. (4) The sulphide ion gives with alkaline sodium nitroprusside a violet colour. (a) 1 and 3 (b) 2 and 4 (c) 1,2 and 4 (d) 2,3 and 4

Which is correctly matched here? List I 1\. Aniline yellow 2\. Phenyl azo \(\beta\) - naphthol 3\. p-nitro acetanilide 4\. Mohr's salt The correct matching is? 1 2 3 4 (a) (ii) (i) (iv) (iii) (b) (i) (ii) (iv) (iii) (c) (ii) (i) (iii) (iv) (d) (i) (iv) (ii) (iii)

A certain pale-green substance, \(X\) becomes dark brown on adding \(\mathrm{NaNO}_{2}\) in presence of dil. \(\mathrm{H}_{2} \mathrm{SO}_{4}\). its aqueous solution gives precipitates with (i) \(\mathrm{BaCl}_{2}\) and (ii) \(\mathrm{NaOH}\) in separate tests. The latter \(\mathrm{NaOH}\) in separate tests. The latter precipitate, Y, gradually changes colour from green to brown, on exposure to air. Identify X here? (a) \(\mathrm{NiSO}_{4}\) (b) \(\mathrm{FeSO}_{4}\) (c) \(\mathrm{ZnSO}_{4}\) (d) \(\mathrm{Cr}_{2}\left(\mathrm{SO}_{4}\right)_{3}\)

Which of the following salts will form colourless beads in borax bead test? (a) \(\mathrm{CoCl}_{2}\) (b) \(\mathrm{Ba}\left(\mathrm{NO}_{3}\right)_{2}\) (c) \(\mathrm{K}_{2} \mathrm{C}_{2} \mathrm{O}_{4}\) (d) \(\mathrm{CoC}_{2} \mathrm{O}_{4}\)

Which of the following sulphates are soluble in water? (a) \(\mathrm{PbSO}_{4}\) (b) \(\mathrm{CuSO}_{4}\) (c) \(\mathrm{BaSO}_{4}\) (D) \(\mathrm{Ag}_{2} \mathrm{SO}_{4}\)

An aqueous solution containing \(\mathrm{S}^{2-}\) ions will not give (a) White precipitate with \(\mathrm{CaCO}_{3}\) suspension (b) Purple colour with sodium thiosulphate solution (c) A yellow precipitate with the suspension of \(\mathrm{CdCO}_{3}\) in water (d) Black precipitate with lead acetate solution

Which of the following radicals are decomposed by conc. \(\mathrm{H}_{2} \mathrm{SO}_{4}\) only? (a) \(\mathrm{C}_{2} \mathrm{O}_{4}^{2-}\) (b) \(\mathrm{HCO}_{3}^{-}\) (c) \(\mathrm{SO}_{3}^{2-}\) (d) \(\mathrm{CH}_{3} \mathrm{COO}^{-}\)

To the aqueous solution of the salt acidified potassium permanganate is added and its colour is discharged. It indicates the absence of (a) \(\mathrm{Sn}^{2+}\) (b) \(\mathrm{Be}^{2+}\) (c) \(\mathrm{Fe}^{2+}\) (d) \(\mathrm{NO}_{3}\)

Which among the species will be soluble in excess of \(\mathrm{NaOH} ?\) (a) \(\mathrm{ZnCl}_{2}\) (b) \(\mathrm{Sr}_{2} \mathrm{~S}_{3}\) (c) \(\mathrm{CuS}\) (d) \(\mathrm{AlCl}_{2}\)

Which of the following of compound will not turn black on adding \(\mathrm{NH}_{4} \mathrm{OH}\) to it (a) \(\mathrm{Hg}_{2} \mathrm{Cl}_{2}\) (b) \(\mathrm{PbCl}_{2}\) (c) \(\mathrm{BaCl}_{2}\) (d) \(\mathrm{AgCl}\)

Which of the following compounds are water soluble? (a) \(\mathrm{ZnSO}_{4}\) (b) \(\left[\mathrm{Zn}\left(\mathrm{NH}_{3}\right)_{4}\right](\mathrm{OH})_{2}\) (c) \(\mathrm{ZnS}\) (d) \(\mathrm{Na}_{2} \mathrm{ZnO}_{2}\)

Brown vapours can be of (a) \(\mathrm{Br}_{2}\) (b) \(\mathrm{NO}_{2}\) (c) \(\mathrm{HCl}\) (d) \(\mathrm{HBr}\)

Which ion can show different colours in different compounds? (a) \(\mathrm{Sr}^{2+}\) (b) \(\mathrm{Ni}^{2+}\) (c) \(\mathrm{Pb}^{2+}\) (d) \(\mathrm{Cd}^{2+}\)

If \(\mathrm{Pb}\left[\mathrm{CH}_{3} \mathrm{COO}\right]_{2}\) and \(\mathrm{Na}_{2} \mathrm{~S}\) are mixed and dissolved in water and the solution is filtered then the filtrate will give test of (a) \(\mathrm{CH}_{3} \mathrm{COO}^{-}\) (b) \(\mathrm{Pb}^{2+}\) (c) \(\mathrm{Na}^{+}\) (d) \(\mathrm{S}^{2-}\)

The hybridisation of \(\mathrm{B}\) in borax is (a) sp (b) \(\mathrm{sp}^{2}\) (c) \(\mathrm{sp}^{3}\) (d) Both (B) and (C)

Glassy bead is of (a) \(\mathrm{Na}_{3} \mathrm{BO}_{3}\) (b) \(\mathrm{B}_{2} \mathrm{O}_{3}+\mathrm{NaBO}_{2}\) (c) \(\mathrm{SiO}_{2}\) (d) \(\mathrm{Na}_{2} \mathrm{~B}_{4} \mathrm{O}_{7}\)

The colour of bead \(\mathrm{Ni}\left(\mathrm{BO}_{2}\right)_{2}\) is of (a) Brown (b) Blue (c) Green (d) Violet

The flame used in borax bead test is (a) Oxidising (b) Reducing (c) Both (A) and (B) (d) Neither (A) nor (B)

Match the following List-I a. \(\mathrm{AgNO}_{3}+\mathrm{NaCNS}\) b. \(\mathrm{AgNO}_{3}+\mathrm{Na}_{3} \mathrm{PO}_{4}\) c. \(\mathrm{AgNO}_{3}+\mathrm{K}_{2} \mathrm{CrO}_{4}\) d. \(\mathrm{AgNO}_{3}+\mathrm{Na}_{2} \mathrm{~S}\) List-II (p) White (q) Black (r) Brick red 1 (s) Yellow

Match the following List-I a. Chromyl chloride test b. Ring test c. Smell of vinegar d. Smell of rotten eggs List-II (p) \(\mathrm{CH}_{3} \mathrm{COO}^{-}\) (q) \(\mathrm{S}^{2}-\) (r) \(\mathrm{Cl}\) (s) \(\mathrm{NO}_{3}^{-}\)

\(0.2063 \mathrm{~g}\) of an organic compound (molar mass 168 ) was heated with sufficient amount of HI and the resulting solution was treated with alcoholic \(\mathrm{AgNO}_{3}\) solution. This led to precipitation of \(0.8658 \mathrm{~g}\) of \(\mathrm{AgI}\). The number of methoxy groups in one molecule of the organic compound is/are (Given : Atomic mass of \(\mathrm{Ag}=108, \mathrm{I}=127)\) (a) 2 (b) 3 (c) 1 (d) 4

When \(\mathrm{H}_{2} \mathrm{~S}\) is passed through \(\mathrm{Hg}_{2}{\underline{\phantom{xx}}}^{2+}\), we get (a) \(\mathrm{Hg}_{2} \mathrm{~S}\) (b) \(\mathrm{HgS}\) (c) \(\mathrm{HgS}+\mathrm{Hg}_{2} \mathrm{~S}\) (d) \(\mathrm{HgS}+\mathrm{Hg}\)

How do we differentiate between \(\mathrm{Fe}^{3+}\) and \(\mathrm{Cr}^{3+}\) in group III? (a) by increasing \(\mathrm{NH}_{4}{\underline{\phantom{xx}}}^{+}\)ion concentration (b) by decreasing \(\mathrm{OH}^{-}\)ion concentration (c) by adding excess of \(\mathrm{NH}_{4}\) OH solution (d) both (a) and (b)

Which one of the following statement is correct? (a) Ferric ions give a deep green precipitate on adding potassium ferrocyanide solution (b) From a mixed precipitate of \(\mathrm{AgCl}\) and \(\mathrm{AgI}\), ammonia solution dissolves only \(\mathrm{AgCl}\) (c) Manganese salts give a violet borax bead test in the reducing flame (d) On boiling a solution having \(\mathrm{K}^{+}, \mathrm{Ca}^{2+}\) and \(\mathrm{HCO}_{3}^{-}\) ions we get a precipitate of \(\mathrm{K}_{2} \mathrm{Ca}\left(\mathrm{CO}_{3}\right)_{2}\)

Calomel \(\left(\mathrm{Hg}_{2} \mathrm{Cl}_{2}\right)\) on reaction with ammonium hydroxide gives (a) \(\mathrm{HgO}\) (b) \(\mathrm{Hg}_{2} \mathrm{O}\) (c) \(\mathrm{HgNH}_{2} \mathrm{Cl}\) (d) \(\mathrm{NH}_{2}-\mathrm{Hg}-\mathrm{Hg}-\mathrm{Cl}\)

Among the following the one that gives positive iodoform test upon reaction with \(\mathrm{I}_{2}\) and \(\mathrm{NaOH}\) is (a) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}(\mathrm{OH}) \mathrm{CH}_{2} \mathrm{CH}_{3}\) (b) \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{OH}\) (c) \(\mathrm{CH}_{3}-\mathrm{CHCH}_{2} \mathrm{OH}\) (d) \(\mathrm{PhCHOHCH}_{3}\)

In the chemical reactions, \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{NH}_{2}+\mathrm{CHCl}_{3}+3 \mathrm{KOH} \longrightarrow\) (a) \(+(\mathrm{b})+3 \mathrm{H}_{2} \mathrm{O}\), the compounds (a) and (b) are respectively: (a) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CONH}_{2}\) and \(3 \mathrm{KCl}\) (b) \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{NC}\) and \(\mathrm{K}_{2} \mathrm{CO}_{3}\) (c) \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{NC}\) and \(3 \mathrm{KCl}\) (d) \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{CN}\) and \(3 \mathrm{KCl}\)

Amount of oxalic acid present in a solution can be determined by its titration with \(\mathrm{KMnO}_{4}\) solution in the presence of \(\mathrm{H}_{2} \mathrm{SO}_{4} .\) The titration gives unsatisfactory result when carried out in the presence of \(\mathrm{HCl}\), because of (a) Gets oxidized by oxalic acid to chlorine (b) Furnishes \(\mathrm{H}^{+}\)ions in addition to those from oxalic acid (c) Reduces permanganate to \(\mathrm{Mn}^{2+}\) (d) Oxidises oxalic acid to carbon dioxide and water

Silver Mirror test is given by which one of the following compounds? (a) Acetone (b) Formaldehyde (c) Benzophenone (d) Acetaldehyde

Which of the following compounds is not colored yellow? (a) \(\mathrm{Zn}_{2}\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]\) (b) \(\mathrm{K}_{3}\left[\mathrm{Co}\left(\mathrm{NO}_{2}\right)_{6}\right]\) (c) \(\left(\mathrm{NH}_{4}\right)_{3}\left[\mathrm{AS}\left(\mathrm{Mo}_{3} \mathrm{O}_{10}\right)_{4}\right]\) (d) \(\mathrm{BaCrO}_{4}\)