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JEE Mains | PYQ

Which of the following sets includes all the species that will change the orange colour of \( \mathrm{K_2Cr_2O_7} \) in acidic medium?

In the structure of the dichromate ion, there is a:

The spin-only magnetic moment value of \( \mathrm{M^{3+}} \) ion (in gaseous state) from the pairs \( \mathrm{Cr^{3+}/Cr^{2+}} \), \( \mathrm{Mn^{3+}/Mn^{2+}} \), \( \mathrm{Fe^{3+}/Fe^{2+}} \) and \( \mathrm{Co^{3+}/Co^{2+}} \) that has negative standard electrode potential, is ________ \( \text{B. M.} \). [Nearest integer]

The metal ions that have the calculated spin-only magnetic moment value of \( 4.9 \, \text{B.M.} \) are:
(A) \( \mathrm{Cr^{2+}} \)
(B) \( \mathrm{Fe^{2+}} \)
(C) \( \mathrm{Fe^{3+}} \)
(D) \( \mathrm{Co^{2+}} \)
(E) \( \mathrm{Mn^{3+}} \)
Choose the correct answer from the options given below:

The most common oxidation state of Lanthanoid elements is \( +3 \). Which of the following is likely to deviate easily from \( +3 \) oxidation state?

The correct order of basicity of oxides of vanadium is:

The correct statement among the following are:
A. \( \mathrm{Mo(VI)} \) and \( \mathrm{W(VI)} \) are less stable than \( \mathrm{Cr(VI)} \).
B. \( \mathrm{Ce^{4+}} \) and \( \mathrm{Tb^{4+}} \) are oxidant while \( \mathrm{Eu^{2+}} \) and \( \mathrm{Yb^{2+}} \) are reductant.
C. \( \mathrm{Cm} \) and \( \mathrm{Am} \) have seven unpaired electrons.
D. Actinoid contraction is greater from element to element than lanthanoid contraction.
Choose the correct answer from the option given below:

The number of terminal oxygen atoms present in the product \( B \) obtained from the following reaction is __________.
\( \mathrm{FeCr_2O_4 + Na_2CO_3 + O_2 \rightarrow A + Fe_2O_3 + CO_2} \)
\( A + \mathrm{H^+} \rightarrow B + \mathrm{H_2O} + \mathrm{Na^+} \)

The total change in the oxidation state of manganese involved in the reaction of \( \text{KMnO}_4 \) and potassium iodide in the acidic medium is __________.

Which halogen is known to cause the reaction given below:
\( 2\mathrm{Cu^{2+}} + 4\mathrm{X^-} \rightarrow \mathrm{Cu_2X_2} \, \mathrm{(s)} + \mathrm{X_2} \)

The incorrect statement among the following is:

The number of ions from the following that have the ability to liberate hydrogen from a dilute acid is ______.
\( \mathrm{Ti^{2+}} \), \( \mathrm{Cr^{2+}} \) and \( \mathrm{V^{2+}} \).

Given below are two statements:
Statement I: The number of pairs among \( [\mathrm{Al_2O_3}, \mathrm{Cr_2O_3}], [\mathrm{Cl_2O_7}, \mathrm{Mn_2O_7}], [\mathrm{Na_2O}, \mathrm{V_2O_3}] \) and \( [\mathrm{CO}, \mathrm{N_2O}] \) that contain oxides of same nature (acidic, basic, neutral or amphoteric) is \( 4 \).
Statement II: Among \( \mathrm{Na_2O}, \mathrm{Al_2O_3}, \mathrm{CO} \) and \( \mathrm{Cl_2O_7} \), the most basic and acidic oxides are \( \mathrm{Na_2O} \) and \( \mathrm{Cl_2O_7} \), respectively.
In the light of the above statements, choose the correct answer from the options given below:

In chromyl chloride test for confirmation of \( \mathrm{Cl^-} \) ion, a yellow solution is obtained. Acidification of the solution and addition of amyl alcohol and \( 10\% \) \( \mathrm{H_2O_2} \) turns organic layer blue indicating formation of chromium pentoxide. The oxidation state of chromium in that is:

In the given chemical reaction, colors of the \( \mathrm{Fe^{2+}} \) and \( \mathrm{Fe^{3+}} \) ions, are respectively:
\( 5\mathrm{Fe^{2+}} + \mathrm{MnO_4^-} + 8\mathrm{H^+} \rightarrow \mathrm{Mn^{2+}} + 4\mathrm{H_2O} + 5\mathrm{Fe^{3+}} \)

The spin only magnetic moment \( (\mu) \) value (B.M.) of the compound with strongest oxidising power among \( \mathrm{Mn_2O_3} \), \( \mathrm{TiO} \) and \( \mathrm{VO} \) is __________ B.M. (Nearest integer).

\( \mathrm{KMnO_4} \) oxidises \( \mathrm{I^-} \) in acidic and neutral/faintly alkaline solution, respectively, to:

On reaction of Lead Sulphide with dilute nitric acid which of the following is not formed?

Among the following, which is the strongest oxidizing agent?

\( \mathrm{MnO_4^{2-}} \), in acidic medium, disproportionate to:

A transition metal 'M' among Sc, Ti, V, Cr, Mn and Fe has the highest second ionization enthalpy. The spin-only magnetic moment value of \( \mathrm{M^{+}} \) ion is ______ BM (Near integer)
(Given atomic number Sc : \( 21 \), Ti : \( 22 \), V : \( 23 \), Cr : \( 24 \), Mn : \( 25 \), Fe : \( 26 \)))

The number of statement(s) correct from the following for Copper (at no. \( 29 \)) is/are_______.
\( (A) \) \( \mathrm{Cu(II)} \) complexes are always paramagnetic
\( (B) \) \( \mathrm{Cu(I)} \) complexes are generally colourless
\( (C) \) \( \mathrm{Cu(I)} \) is easily oxidized
\( (D) \) In Fehling solution, the active reagent has \( \mathrm{Cu(I)} \)

The electronic configuration of \( \text{Cu(II)} \) is \( 3d^{9} \) whereas that of \( \text{Cu(I)} \) is \( 3d^{10} \). Which of the following is correct?

The number of \( f \) electrons in the ground state electronic configuration of \( \mathrm{Np} \) (\( Z = 93 \)) is __________. (Integer answer)

Given below are two statements:
Statement I: \( \mathrm{CrO_3} \) is a stronger oxidizing agent than \( \mathrm{MoO_3} \)
Statement II: \( \mathrm{Cr(VI)} \) is more stable than \( \mathrm{Mo(VI)} \)
In the light of the above statements, choose the correct answer from the options given below:

"\( X \)" is an oxoanion of the lightest element of group \( 7 \) (in the periodic table). The metal is in \( +6 \) oxidation state in "\( X \)". The color of the potassium salt of \( X \) is:

The orange colour of \( \mathrm{K_2Cr_2O_7} \) and purple colour of \( \mathrm{KMnO_4} \) is due to:

On complete reaction of \( \mathrm{FeCl_3} \) with oxalic acid in aqueous solution containing \( \mathrm{KOH} \), resulted in the formation of product A. The secondary valency of \( \mathrm{Fe} \) in the product A is _______. (Round off to the Nearest Integer)

The number of \( 4f \) electrons in the ground state electronic configuration of \( \mathrm{Gd^{2+}} \) is ______.
[Atomic nuclear of Gd \( = 64 \)]

In alkaline medium, the reduction of permanganate anion involves a gain of _______ electrons.

Given below are two statements.
Statement I: Iron (\( \text{III} \)) catalyst, acidified \( \mathrm{K_2Cr_2O_7} \) and neutral \( \mathrm{KMnO_4} \) have the ability to oxidise \( \mathrm{I^-} \) and \( \mathrm{I_2} \) independently.
Statement II: Manganate ion is paramagnetic in nature and involves \( p\pi - p\pi \) bonding.
In the light of the above statements, choose the correct answer from the options given below:

Which of the following elements have half-filled f-orbitals in their ground state? (Given: atomic number \( \mathrm{Sm} = 62 \); \( \mathrm{Eu} = 63 \); \( \mathrm{Tb} = 65 \); \( \mathrm{Gd} = 64 \), \( \mathrm{Pm} = 61 \))
A. \( \mathrm{Sm} \) B. \( \mathrm{Eu} \) C. \( \mathrm{Tb} \) D. \( \mathrm{Gd} \) E. \( \mathrm{Pm} \)

Identify correct statements from below:
A. The chromate ion is square planar.
B. Dichromates are generally prepared from chromates.
C. The green manganate ion is diamagnetic.
D. Dark green coloured \( \mathrm{K_2MnO_4} \) disproportionates in a neutral or acidic medium to give permanganate.
E. With increasing oxidation number of transition metal, ionic character of the oxides decreases.
Choose the correct answer from the options given below:

Acidified potassium permanganate solution oxidises oxalic acid. The spin-only magnetic moment of the manganese product formed from the above reaction is ________ B.M.

Pair of transition metal ions having the same number of unpaired electrons is:

Which statement is not true with respect to nitrate ion test?

Which one of the lanthanoids given below is the most stable in divalent form?

The difference in oxidation state of chromium in eliminate and dichromate salts is ______________.

Given below are two statements:
Statement-I: The number of pairs among \( [\mathrm{Ti}^{4+}, \mathrm{V}^{2+}] \), \( [\mathrm{V}^{2+}, \mathrm{Mn}^{2+}] \), \( [\mathrm{Mn}^{2+}, \mathrm{Fe}^{3+}] \) and \( [\mathrm{V}^{2+}, \mathrm{Cr}^{2+}] \) in which both ions are coloured is \( 3 \).
Statement-II: The number of pairs among \( [\mathrm{La}^{3+}, \mathrm{Yb}^{2+}] \), \( [\mathrm{Lu}^{3+}, \mathrm{Ce}^{4+}] \) and \( [\mathrm{Ac}^{3+}, \mathrm{Lr}^{3+}] \) ions in which both are diamagnetic is \( 3 \).
In the light of the above statements, choose the correct answer from the options given below:

The set having ion which are coloured and paramagnetic both is:

Cerium (IV) has a noble gas configuration. Which of the following is correct statement about it?

The electronic configuration of Einsteinium is:
(Given atomic number of Einsteinium = \( 99 \))

Among the following oxides of \( 3d \) elements, the number of mixed oxides are _________ .
\( \mathrm{Ti_2O_3} \), \( \mathrm{V_2O_4} \), \( \mathrm{Cr_2O_3} \), \( \mathrm{Mn_3O_4} \), \( \mathrm{Fe_3O_4} \), \( \mathrm{Fe_2O_3} \), \( \mathrm{Co_3O_4} \)

Diamagnetic Lanthanoid ions are:

Sulphide ion is soft base and its ores are common for metals.
\( (a) \) Pb \( \quad (b) \) Al \( \quad (c) \) Ag \( \quad (d) \) Mg
Choose the correct answer from the options given below:

Total number of ions from the following with noble gas configuration is __________. \( \mathrm{Sr^{2+}} \, (z = 38), \ \mathrm{Cs^{+}} \, (z = 55), \ \mathrm{La^{2+}} \, (z = 57), \ \mathrm{Pb^{2+}} \, (z = 82), \ \mathrm{Yb^{2+}} \, (z = 70) \) and \( \mathrm{Fe^{2+}} \, (z = 26) \).

An acidified manganite solution undergoes disproportionation reaction. The spin-only magnetic moment value of the product having manganese in higher oxidation state is __________ B.M. (Nearest integer)

Among \( \mathrm{VO_2^+}, \ \mathrm{MnO_4^-} \) and \( \mathrm{Cr_2O_7^{2-}} \), the spin-only magnetic moment value of the species with least oxidizing ability is ______ \( \text{BM} \) (Nearest integer).
(Given atomic member \( \mathrm{V} = 23 \), \( \mathrm{Mn} = 25 \), \( \mathrm{Cr} = 24 \))

The number of valence electrons present in the metal among Cr, Co, Fe and Ni which has the lowest enthalpy of atomization is:

Among \( \mathrm{CrO} \), \( \mathrm{Cr_2O_3} \) and \( \mathrm{CrO_3} \), the sum of spin-only magnetic moment values of basic and amphoteric oxides is _______ \( 10^{-2} \) \( \mathrm{BM} \) (nearest integer). {Given atomic number of \( \mathrm{Cr} \) is \( 24 \)}

Given below are two statements:
Statement I: Aqueous solution of \( \mathrm{K}_2\mathrm{Cr}_2\mathrm{O}_7 \) is preferred as a primary standard in volumetric analysis over \( \mathrm{Na}_2\mathrm{Cr}_2\mathrm{O}_7 \) aqueous solution.
Statement II: \( \mathrm{K}_2\mathrm{Cr}_2\mathrm{O}_7 \) has a higher solubility in water than \( \mathrm{Na}_2\mathrm{Cr}_2\mathrm{O}_7 \).
In the light of the above statements, choose the correct answer from the options given below:

The reaction of zinc with excess of aqueous alkali, evolves hydrogen gas and gives:

Given below are two statements:
Statement I : Potassium permanganate on heating at \( 573 \, \mathrm{K} \) forms potassium manganate.
Statement II : Both potassium permanganate and potassium manganate are tetrahedral and paramagnetic in nature.
In the light of the above statements, choose the most appropriate answer from the options given below:

Identify the element for which electronic configuration in \( +3 \) oxidation state is \( [\text{Ar}]3d^5 \):

Which one of the following when dissolved in water gives coloured solution in nitrogen atmosphere?

Consider \( |x| \) is the difference in oxidation states of \( \mathrm{Mn} \) in highest manganese fluoride and highest manganese oxide. The ions with \( |x| \) number of unpaired electrons from the following are:
A. \( \mathrm{Sc}^{3+} \)   B. \( \mathrm{Zn}^{2+} \)   C. \( \mathrm{V}^{2+} \)   D. \( \mathrm{Fe}^{2+} \)   E. \( \mathrm{Co}^{2+} \)
Choose the correct answer from the options given below:

The common positive oxidation states for an element with atomic number \( 24 \), are :

The nature of oxides \( \mathrm{V_2O_3} \) and \( \mathrm{CrO} \) is indexed as 'X' and 'Y' type respectively. The correct set of X and Y is:

Number of colourless lanthanoid ions among the following is _______. \( \text{Eu}^{3+}, \text{Lu}^{3+}, \text{Nd}^{3+}, \text{La}^{3+}, \text{Sm}^{3+} \)

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): In aqueous solutions \( \mathrm{Cr}^{2+} \) is reducing while \( \mathrm{Mn}^{3+} \) is oxidizing in nature.
Reason (R): Extra stability to half filled electronic configuration is observed than incompletely filled electronic configuration.
In the light of the above statements, choose the most appropriate answer from the options given below:

Strong reducing and oxidizing agents among the following, respectively, are:

Match List-I with List-II.

Choose the correct answer from the options given below:

Given are two statements:
Statement (I): Fusion of \( \mathrm{MnO_2} \) with \( \mathrm{KOH} \) and an oxidizing agent gives dark green \( \mathrm{K_2MnO_4} \).
Statement (II): Manganate ion electrolytic oxidation in alkaline medium gives permanganate ion.
In the light of the above statements, choose the correct answer from the options given below;

Consider the following reactions:
\( K_2Cr_2O_7 \xrightarrow[\ -H_2O\ ]{KOH} [A] \xrightarrow[\ -H_2O\ ]{H_2SO_4} [B] + K_2SO_4 \) 
The products [A] and [B], respectively, are:

In neutral or faintly alkaline medium, \( \mathrm{KMnO_4} \) being a powerful oxidant can oxidize, thiosulphate almost quantitatively, to sulphate. In this reaction overall change in oxidation state of manganese will be:

Consider the following reactions.

$ \text{PbCl}_2 + \text{K}_2\text{CrO}_4 \rightarrow \text{A} + 2\text{KCl} $

(Hot solution)

$ \text{A} + \text{NaOH} \rightleftharpoons \text{B} + \text{Na}_2\text{CrO}_4 $

$ \text{PbSO}_4 + 4\text{CH}_3\text{COONH}_4 \rightarrow (\text{NH}_4)_2\text{SO}_4 + \text{X} $

In the above reactions, A, B and X are respectively.

The number of hydrogen bonded water molecule(s) associated with stoichiometry \( \mathrm{CuSO_4\cdot 5H_2O} \) is ____________ .

Which one amongst the following are good oxidizing agents?
(A) \( \mathrm{Sm^{2+}} \) (B) \( \mathrm{Ce^{2+}} \) (C) \( \mathrm{Ce^{4+}} \) (D) \( \mathrm{Tb^{4+}} \)
Choose the most appropriate answer from the options given below:

The correct statements among the following are.
A. Basic vanadium oxide is used in the manufacture of \( \text{H}_2\text{SO}_4 \)
B. The spin-only magnetic moment value of the transition metal halide employed in Ziegler-Natta polymerization is \( 2.84 \) BM.
C. The p-block metal compound employed in Ziegler-Natta polymerization has the metal in \( +3 \) oxidation state.
D. The number of electrons present in the outer most ‘d’ orbital of metal halide employed in Wacker process is \( 8 \).

Given below are some of the statements about \( \mathrm{Mn} \) and \( \mathrm{Mn_2O_7} \). Identify the correct statements.
A. \( \mathrm{Mn} \) forms the oxide \( \mathrm{Mn_2O_7} \), in which \( \mathrm{Mn} \) is in its highest oxidation state.
B. Oxygen stabilizes the \( \mathrm{Mn} \) in higher oxidation states by forming multiple bonds with \( \mathrm{Mn} \).
C. \( \mathrm{Mn_2O_7} \) is an ionic oxide.
D. The structure of \( \mathrm{Mn_2O_7} \) consists of one bridged oxygen.
Choose the correct answer from the options given below:

Identify the metal ions among \( \mathrm{Co^{2+}, Ni^{2+}, Fe^{2+}, V^{3+}} \) and \( \mathrm{Ti^{2+}} \) having a spin-only magnetic moment value more than \( 3.0 \, \mathrm{BM} \). The sum of unpaired electrons present in the high spin octahedral complexes formed by those metal ions is _____ .

Given below are two statements:

Statement I: The number of pairs, from the following, in which both the ions are coloured in aqueous solution is \( 3 \).

\( [\mathrm{Sc^{3+}},\, \mathrm{Ti^{3+}}] \), \( [\mathrm{Mn^{2+}},\, \mathrm{Cr^{2+}}] \), \( [\mathrm{Cu^{2+}},\, \mathrm{Zn^{2+}}] \) and \( [\mathrm{Ni^{2+}},\, \mathrm{Ti^{4+}}] \)

Statement II: The \( \mathrm{Th^{4+}} \) is the strongest reducing agent among \( \mathrm{Th^{4+}} \), \( \mathrm{Ce^{4+}} \), \( \mathrm{Gd^{3+}} \) and \( \mathrm{Eu^{2+}} \).

In the light of the above statements, choose the correct answer from the options given below:

The magnetic moment of a transition metal compound has been calculated to be \( 2.87 \) B.M. The metal ion is:

The \( f \) orbitals are half and completely filled, respectively in lanthanide ions
[Given : Atomic no. Eu, \( 63 \); Sm, \( 62 \); Tm, \( 69 \); Tb, \( 65 \); Yb, \( 70 \); Dy, \( 66 \)]

Choose the correct statements from the following.
A \( \mathrm{Mn_2O_7} \) is an oil at room temperature
B \( \mathrm{V_2O_4} \) reacts with acid to give \( \mathrm{VO_2^{2+}} \)
C \( \mathrm{CrO} \) is a basic oxide
D \( \mathrm{V_2O_5} \) does not react with acid
Choose the correct answer from the options given below:

Cobalt chloride when dissolved in water forms pink colored complex $\underline{\text{X}}$ which has octahedral geometry. 

This solution on treating with conc $\text{HCl}$ forms deep blue complex, $\underline{\text{Y}}$ which has a $\underline{\text{Z}}$ geometry. $\text{X}$, $\text{Y}$ and $\text{Z}$, respectively are:

Niobium \( (\mathrm{Nb}) \) and ruthenium \( (\mathrm{Ru}) \) have "x" and "y" number of electrons in their respective \( 4d \) orbitals. The value of \( x + y \) is \( \_\_\_\_\_\_\_\_\_\_ \).

Number of paramagnetic ions among the following d- and f-block metal ions is ________.
\( \text{Mn}^{2+}, \text{Cu}^{2+}, \text{Zn}^{2+}, \text{Yb}^{2+}, \text{Sc}^{3+}, \text{La}^{3+}, \text{Gd}^{3+}, \text{Lu}^{3+}, \text{Ti}^{4+}, \text{Ce}^{4+} \).
(Atomic number of Mn \( = 25 \), Cu \( = 29 \), Zn \( = 30 \), Yb \( = 70 \), Sc \( = 21 \), La \( = 57 \), Gd \( = 64 \), Lu \( = 71 \), Ti \( = 22 \), Ce \( = 58 \))

‘A first-row transition metal in its \( +2 \) oxidation state has a spin-only magnetic moment value of \( 3.86 \, \text{BM} \). The atomic number of the metal is:

\( \text{FeX}_2 \) and \( \text{FeY}_3 \) are known when x and y are:

Consider the following reactions:

The number of terminal ‘\( \text{O} \)’ present in the compound ‘\( \text{C} \)’ is __________.

Among \( 10^{-9} \,\text{g} \) (each) of the following elements, which one will have the highest number of atoms? Element: \( \text{Pb} \), \( \text{Po} \), \( \text{Pr} \) and \( \text{Pt} \)

Which one of the following lanthanides exhibits \( +2 \) oxidation state with diamagnetic nature? (Given \( Z \) for Nd \( = 60 \), Yb \( = 70 \), La \( = 57 \), Ce \( = 58 \))

The transition metal having highest \( 3^{rd} \) ionisation enthalpy is:

\( X \) and \( Y \) are the number of electrons involved, respectively during the oxidation of \( \mathrm{I^-} \) to \( \mathrm{I_2} \), and of \( \mathrm{S^{2-}} \) to \( \mathrm{S} \) by acidified \( \mathrm{K_2Cr_2O_7} \). The value of \( X + Y \) is ________.

Which of the following \( 3d \)-metal ion will give the lowest enthalpy of hydration \( (\Delta_{\mathrm{hyd}} H) \) when dissolved in water?

Preparation of potassium permanganate from \( \mathrm{MnO_2} \) involves two step process in which the \( 1^{\text{st}} \) step is a reaction with \( \mathrm{KOH} \) and \( \mathrm{KNO_3} \) to produce:

The correct option with order of melting points of the pairs \((\mathrm{Mn}, \mathrm{Fe})\), \((\mathrm{Tc}, \mathrm{Ru})\) and \((\mathrm{Re}, \mathrm{Os})\) is:

In following pairs, the one in which both transition metal ions are colourless is:

In chromyl chloride the number of d-electrons present on chromium is same as in:
(Given atomic number of Ti : \( 22 \), V : \( 23 \), Cr : \( 24 \), Mn : \( 25 \), Fe : \( 26 \))

Which of the following is NOT a physical or chemical characteristics of interstitial compounds?

‘\(X\)’ is the number of acidic oxides among \(VO_2\), \(V_2O_3\), \(CrO_3\), \(V_2O_5\) and \(Mn_2O_7\). The primary valency of cobalt in \([Co(H_2NCH_2CH_2NH_2)_3]_2(SO_4)_3\) is \(Y\). The value of \(X + Y\) is ____________.

Ice at \( -5^\circ \text{C} \) is heated to become vapor with temperature of \( 110^\circ \text{C} \) at atmospheric pressure. The entropy change associated with this process can be obtained from:

The amphoteric oxide among \( V_2O_3 \), \( V_2O_4 \) and \( V_2O_5 \), upon reaction with alkali leads to formation of an oxide anion. The oxidation state of \( V \) in the oxide anion is:

The spin-only magnetic moment value of the ion among \( \mathrm{Ti^{2+}} \), \( \mathrm{V^{2+}} \), \( \mathrm{Co^{3+}} \) and \( \mathrm{Cr^{2+}} \), that acts as strong oxidizing agent in aqueous solution is \( \_\_\_\_\_\_\_\_ \) \( \text{BM} \) (Near integer).
(Given atomic number : \( \mathrm{Ti: \, 22} \), \( \mathrm{V: \, 23} \), \( \mathrm{Cr: \, 24} \), \( \mathrm{Co: \, 27} \))

\( \mathrm{Nd}^{2+} = \_\_\_\_\_ \)

The spin-only magnetic moment value of the compound with strongest oxidizing ability among \( \mathrm{MnF_4} \), \( \mathrm{MnF_3} \) and \( \mathrm{MnF_2} \) is ________ B.M. (nearest integer)

Consider the following reaction \( \mathrm{MnO_2} + \mathrm{KOH} + \mathrm{O_2} \rightarrow A + \mathrm{H_2O} \). Product ‘A’ in neutral or acidic medium disproportionate to give products ‘B’ and ‘C’ along with water. The sum of spin-only magnetic moment values of B and C is ______ \( \text{BM} \). (nearest integer) (Given atomic number of Mn is \( 25 \))

In alkaline medium, \( \mathrm{MnO_4^-} \) oxidises \( \mathrm{I^-} \) to:

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R)
Assertion (A): The first ionization enthalpy of \( 3d \) series elements is more than that of group \( 2 \) metals
Reason (R): In \( 3d \) series of elements successive filling of d-orbitals takes place.
In the light of the above statements, choose the correct answer from the options given below:

Match List I with List II.

Choose the correct answer from the option given below:

The correct decreasing order of spin only magnetic moment values (BM) of \( \mathrm{Cu^+} \), \( \mathrm{Cu^{2+}} \), \( \mathrm{Cr^{2+}} \) and \( \mathrm{Cr^{3+}} \) ions is:

Given below are two statements for catalytic properties of transition metals.
Statement-I: First row transition metals which act as catalyst utilise their \( 3d \) electrons only for formation of bonds between reactant molecules and atoms on the surface of catalyst.
Statement-II: There is increase in the concentration of reactants on the surface of catalyst which strengthens the bonds in reacting molecules.
In the light of the above statements, choose the correct answer from the options given below:

When \( \mathrm{Cu^{2+}} \) ion is treated with \( \mathrm{KI} \), a white precipitate, \( X \) appears in solution. The solution is titrated with sodium thiosulphate, the compound \( Y \) is formed, \( X \) and \( Y \) respectively are:

The total number of \( \mathrm{Mn} = \mathrm{O} \) bonds in \( \mathrm{Mn_2O_7} \) is ______.

The number of element from the following that do not belong to lanthanoids is: Eu, Cm, Er, Tb, Yb and Lu

Prolonged heating is avoided during the preparation of ferrous ammonium sulphate to:

What is the correct order of the following elements with respect to their density?

Manganese \( (\text{VI}) \) has ability to disproportionate in acidic solution. The difference in oxidation states of two ions it forms in acidic solution is __________.

Formulae for Nessler’s reagent is:

The fusion of chromite ore with sodium carbonate in the presence of air leads to the formation of products \( A \) and \( B \) along with the evolution of \( \text{CO}_2 \). The sum of spin-only magnetic moment values of \( A \) and \( B \) is ____ B.M. (Nearest integer)
[Given atomic number: \( \text{C}: 6 \), \( \text{Na}: 11 \), \( \text{O}: 8 \), \( \text{Fe}: 26 \), \( \text{Cr}: 24 \)]

The set of correct statements is:
(i) Manganese exhibits \( +7 \) oxidation state in its oxide.
(ii) Ruthenium and Osmium exhibit \( +8 \) oxidation in their oxides.
(iii) Sc shows \( +4 \) oxidation state which is oxidizing in nature.
(iv) Cr shows oxidizing nature in \( +6 \) oxidation state.

Lanthanoid ions with \( 4f^7 \) configuration are:
(A) \( \mathrm{Eu}^{2+} \)                      (B) \( \mathrm{Gd}^{3+} \)
(C) \( \mathrm{Eu}^{3+} \)                      (D) \( \mathrm{Tb}^{3+} \)
(E) \( \mathrm{Sm}^{2+} \)
Choose the correct answer from the options given below:

The correct order of following \( 3d \) metal oxides, according to their oxidation numbers is:
(a) \( \mathrm{CrO_3} \) (b) \( \mathrm{Fe_2O_3} \) (c) \( \mathrm{MnO_2} \) (d) \( \mathrm{V_2O_5} \) (e) \( \mathrm{Cu_2O} \)

The 'spin only' magnetic moment value of \( \mathrm{MO_4^{2-}} \) is ______ \( \mathrm{BM} \).
(Where \( \mathrm{M} \) is a metal having least metallic radii among Sc, Ti, V. Cr. Mn and Zn)
[Given atomic number : Sc \( = 21 \), Ti \( = 22 \), V \( = 23 \), Cr \( = 24 \), Mn \( = 25 \) and Zn \( = 30 \)]

Identify the incorrect pair from the following:

Match List-I with List-II.

Choose the correct answer from the options given below :

Which of the following acts as a strong reducing agent? (Atomic number: \( \mathrm{Ce} = 58 \), \( \mathrm{Eu} = 63 \), \( \mathrm{Gd} = 64 \), \( \mathrm{Lu} = 71 \))

An inorganic Compound ‘X’ on treatment with concentrated \( \text{H}_2\text{SO}_4 \) produces brown fumes and gives dark brown ring with \( \text{FeSO}_4 \) in presence of concentrated \( \text{H}_2\text{SO}_4 \). Also Compound ‘X’ gives precipitate ‘Y’, when its solution in dilute \( \text{HCl} \) is treated with \( \text{H}_2\text{S} \) gas. The precipitate ‘Y’ on treatment with concentrated \( \text{HNO}_3 \) followed by excess of \( \text{NH}_4\text{OH} \) further gives deep blue coloured solution, Compound ‘X’ is:

How many of the following metal ions have similar value of spin only magnetic moment in gaseous state _________ ? (Given: Atomic number: V, \(23\); Cr, \(24\); Fe, \(26\); Ni, \(28\))
\( \mathrm{V^{3+}}, \mathrm{Cr^{3+}}, \mathrm{Fe^{2+}}, \mathrm{Ni^{3+}} \)

The oxidation state of chromium in the final product formed in the reaction between KI and acidified \( \mathrm{K_{2}Cr_{2}O_{7}} \) solution is:

Identify the correct set of reagents or reaction conditions ‘\( X \)’ and ‘\( Y \)’ in the following set of transformation.

Number of electrons present in \( 4f \) orbital of \( \mathrm{Ho^{3+}} \) ion is _______. (Given Atomic No. of \( \mathrm{Ho} = 67 \))

Which of the following compounds show colour due to d-d transition?

Potassium permanganate on heating at \( 513 \, \mathrm{K} \) gives a product which is:

Given below are two statements:
Statement I: The first ionization enthalpy of Cr is lower than that of Mn.
Statement II: The second and third ionization enthalpies of Cr are higher than those of Mn.
In the light of the above statements, choose the correct answer from the options given below:

The first transition series metal ‘M’ has the highest enthalpy of atomisation in its series. One of its aquated ion \( \mathrm{M}^{n+} \) exists in green colour. The nature of the oxide formed by the above \( \mathrm{M}^{n+} \) ion is:

The spin-only magnetic moment value of \( M^{n+} \) ion formed among Ni, Zn, Mn and Cu that has the least enthalpy of atomisation is _____________ (in nearest integer).
Here \( n \) is equal to the number of diamagnetic complexes among \( K_2[NiCl_4] \), \( [Zn(H_2O)_6]Cl_2 \), \( K_3[Mn(CN)_6] \) and \( [Cu(pph_3)_3I] \).

Pairs of elements with the same number of electrons in their respective \( 4f \) orbital are:

[Atomic number: \( \text{Eu-}63 \), \( \text{Gd-}64 \), \( \text{Dy-}66 \), \( \text{Ho-}67 \), \( \text{Tm-}69 \), \( \text{Yb-}70 \), \( \text{Lu-}71 \), \( \text{Hf-}72 \)]

A. (Eu and Gd)    B. (Dy and Ho)
C. (Yb and Hf)    D. (Lu and Tm)

Choose the correct answer from the options given below:

The metal that shows highest and maximum number of oxidation state is:

Which of the following statements are correct?
(A) The \( \mathrm{M}^{3+} / \mathrm{M}^{2+} \) reduction potential for iron is greater than manganese.
(B) The higher oxidation states of first row d-block elements get stabilized by oxide ion
(C) Aqueous solution of \( \mathrm{Cr}^{2+} \) can liberate hydrogen from dilute acid
(D) Magnetic moment of \( \mathrm{V}^{2+} \) is observed between \( 4.4 - 5.2 \) \( \mathrm{BM} \)
Choose the correct answer from the options given below:

The spin-only magnetic moment value of the most basic oxide of vanadium among \( \mathrm{V_2O_3} \), \( \mathrm{V_2O_4} \) and \( \mathrm{V_2O_5} \) is ___________ B.M. (Nearest integer)

The spin only magnetic moments (in BM) for free \( \mathrm{Ti}^{3+} \), \( \mathrm{V}^{2+} \) and \( \mathrm{Sc}^{3+} \) ions respectively are: (Atomic No. \( \mathrm{Sc} = 21 \), \( \mathrm{Ti} = 22 \), \( \mathrm{V} = 23 \))

In the reaction of potassium dichromate, potassium chloride and sulfuric acid (conc.), the oxidation state of the chromium in the product is \( (+) \) ________.

Correct statements from the following are:

A. Potassium dichromate is an oxidizing agent and it oxidises \( \mathrm{FeSO_4} \) to \( \mathrm{Fe_2(SO_4)_3} \) in acidic medium.

B. Sodium dichromate can be used as primary standard in volumetric estimation.

C. \( \mathrm{CrO_4^{2-}} \) and \( \mathrm{Cr_2O_7^{2-}} \) are interconvertible in aqueous solution by varying the \( \mathrm{pH} \) of the solution.

D. \( \mathrm{Cr\!-\!O\!-\!Cr} \) bond angle in \( \mathrm{Cr_2O_7^{2-}} \) is \( 126^\circ \)

Choose the correct answer from the options given below:

Consider the following reactions:

\( \mathrm{NaCl + K_2Cr_2O_7 + H_2SO_4 \rightarrow A + KHSO_4 + NaHSO_4 + H_2O} \)
\( \mathrm{A + NaOH \rightarrow B + NaCl + H_2O} \)
\( \mathrm{B + H_2SO_4 + H_2O_2 \rightarrow C + Na_2SO_4 + H_2O} \)

In the product ‘C’, ‘X’ is the number of \( \mathrm{O_2^{2-}} \) units, ‘Y’ is the total number oxygen atoms present and ‘Z’ is the oxidation state of Cr. The value of \( X + Y + Z \) is __________.

The dark purple colour of \( \mathrm{KMnO_4} \) disappears in the titration with oxalic acid in acidic medium. The overall change in the oxidation number of manganese in the reaction is:

Highest oxidation state of Mn is exhibited in \( \mathrm{Mn_2O_7} \). The correct statements about \( \mathrm{Mn_2O_7} \) are
(A) Mn is tetrahedrally surrounded by oxygen atoms
(B) Mn is octahedrally surrounded by oxygen atoms
(C) Contains Mn-O-Mn bridge
(D) Contains Mn-Mn bond
Choose the correct answer from the option given below:

The difference in the ‘spin-only’ magnetic moment values of \( \mathrm{KMnO_4} \) and the manganese product formed during titration of \( \mathrm{KMnO_4} \) against oxalic acid in acidic medium is ________ \( \mathrm{B.M.} \) (nearest integer)

The pair of lanthanides in which both elements have high third-ionization energy is: