JEE Mains JEE Advance BITSAT
JEE Mains | PYQ

Year

All years 2026 2025 2024 2023 2022 2021

Which of the following oxidation reactions are carried out by both \( \mathrm{K_2Cr_2O_7} \) and \( \mathrm{KMnO_4} \) in acidic medium?
A. \( \mathrm{I^- \rightarrow I_2} \) B. \( \mathrm{S^{2-} \rightarrow S} \) C. \( \mathrm{Fe^{2+} \rightarrow Fe^{3+}} \)

D. \( \mathrm{I^- \rightarrow IO_3^-} \) E. \( \mathrm{S_2O_3^{2-} \rightarrow SO_4^{2-}} \)
Choose the correct answer from the options given below:

Which of the following ions is the strongest oxidizing agent?
(Atomic Number of \( \mathrm{Ce} = 58 \), \( \mathrm{Eu} = 63 \), \( \mathrm{Tb} = 65 \), \( \mathrm{Lu} = 71 \))

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 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).

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:

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

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

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:

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 \( \_\_\_\_\_\_\_\_\_\_ \).

10.

Consider the following reactions:

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

11.

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 \( \text{Pt} \)

12.

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:

13.

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:

14.

‘\(X\)’ 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 ____________.

15.

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:

16.

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:

17.

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:

18.

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:

19.

Match List-I with List-II.

List-I (Transition metal ion)	List-II (spin only magnetic moment (B.M.))
(A) \( \mathrm{Ti^{3+}} \)	(I) \( 3.87 \)
(B) \( \mathrm{V^{2+}} \)	(II) \( 0.00 \)
(C) \( \mathrm{Ni^{2+}} \)	(III) \( 1.73 \)
(D) \( \mathrm{Sc^{3+}} \)	(IV) \( 2.84 \)

Choose the correct answer from the options given below :

20.

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:

21.

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 \( [Cu(pph_3)_3I] \).

← PreviousQuestion 6 of 21Next →

JEE MAIN 2025 4th April Morning Shift

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

JEE MainsJEE AdvanceBITSATJEE Mains | PYQ

JEE Mains JEE Advance BITSAT
JEE Mains | PYQ