Q.60. Given below are two statements :
Statement I: The number of pairs among [Ti, V], [V, Mn], [Mn,

Q: What is the correct answer for JEE Main Chemistry Q60?

The correct answer is A. Sol. Statement I: An ion is coloured if it has unpaired electrons (d-d transitions). Ti$^{4+}$: [Ar]$3d^0$ (colourless) V$^{2+}$: [Ar]$3d^3$ (coloured) Mn$^{2+}$: [Ar]$3d^5$ (coloured) Fe$^{3+}$: [Ar]$3d^5$ (coloured) Cr$^{2+}$: [Ar]$3d^4$ (coloured) Pairs: [Ti$^{4+}$, V$^{2+}$]: Ti$^{4+}$ is colourless, V$^{2+}$ is coloured. (Not both coloured) [V$^{2+}$, Mn$^{2+}$]: Both are coloured. (1st pair)

Q: Q.60. Given below are two statements : Statement I: The number of pairs among [Ti, V], [V, Mn], [Mn, Fe] and [V, Cr] in which both ions are coloured is 3. Statement II: The number pairs among [La,…

The correct answer is A. Sol. Statement I: An ion is coloured if it has unpaired electrons (d-d transitions). Ti$^{4+}$: [Ar]$3d^0$ (colourless) V$^{2+}$: [Ar]$3d^3$ (coloured) Mn$^{2+}$: [Ar]$3d^5$ (coloured) Fe$^{3+}$: [Ar]$3d^5$ (coloured) Cr$^{2+}$: [Ar]$3d^4$ (coloured) Pairs: [Ti$^{4+}$, V$^{2+}$]: Ti$^{4+}$ is colourless, V$^{2+}$ is coloured. (Not both coloured) [V$^{2+}$, Mn$^{2+}$]: Both are coloured. (1st pair)

Q: What are the options for this JEE Main Chemistry question?

A. Both Statement I and Statement II are correct · B. Both Statement I and Statement II are incorrect · C. Statement I is correct but Statement II are incorrect · D. Statement I is incorrect but Statement II are correct

Question

Q.60. Given below are two statements :
Statement I: The number of pairs among [Ti, V], [V, Mn], [Mn, Fe] and [V, Cr] in which both ions are coloured is 3.
Statement II: The number pairs among [La, Yb], [Lu, Ce] and [Ac, Lr] ions in which both are diamagnetic is 3.
In the light of the above statements, choose the correct answer from the option given below :

FirstInTest · Accepted Answer

Sol. Statement I:
An ion is coloured if it has unpaired electrons (d-d transitions).
Ti$^{4+}$: [Ar]$3d^0$ (colourless)
V$^{2+}$: [Ar]$3d^3$ (coloured)
Mn$^{2+}$: [Ar]$3d^5$ (coloured)
Fe$^{3+}$: [Ar]$3d^5$ (coloured)
Cr$^{2+}$: [Ar]$3d^4$ (coloured)
Pairs:
[Ti$^{4+}$, V$^{2+}$]: Ti$^{4+}$ is colourless, V$^{2+}$ is coloured. (Not both coloured)
[V$^{2+}$, Mn$^{2+}$]: Both are coloured. (1st pair)
[Mn$^{2+}$, Fe$^{3+}$]: Both are coloured. (2nd pair)
[V$^{2+}$, Cr$^{2+}$]: Both are coloured. (3rd pair)
So, there are 3 pairs where both ions are coloured. Statement I is correct.
Statement II:
An ion is diamagnetic if it has no unpaired electrons (all electrons are paired).
La$^{3+}$: [Xe]$4f^0$ (diamagnetic)
Yb$^{2+}$: [Xe]$4f^{14}$ (diamagnetic)
Lu$^{3+}$: [Xe]$4f^{14}$ (diamagnetic)
Ce$^{4+}$: [Xe]$4f^0$ (diamagnetic)
Ac$^{3+}$: [Rn]$5f^0$ (diamagnetic)
Lr$^{3+}$: [Rn]$5f^{14}$ (diamagnetic)
Pairs:
[La$^{3+}$, Yb$^{2+}$]: Both are diamagnetic. (1st pair)
[Lu$^{3+}$, Ce$^{4+}$]: Both are diamagnetic. (2nd pair)
[Ac$^{3+}$, Lr$^{3+}$]: Both are diamagnetic. (3rd pair)
So, there are 3 pairs where both ions are diamagnetic. Statement II is correct.
Both Statement I and Statement II are correct.

Answer

Both Statement I and Statement II are correct

Answer

Both Statement I and Statement II are incorrect

Answer

Statement I is correct but Statement II are incorrect

Answer

Statement I is incorrect but Statement II are correct

Related Questionsin Chemistry

More from JEE Main

Browse Engineering Questions by Subject

Practice More JEE Main Questions