back to directory
NEET CHEMISTRYThe d-and f-Block ElementsMedium

Question

When neutral or faintly alkaline KMnO4KMnO_4 is treated with potassium iodide, iodide ion is converted into 'X'. 'X' is:

A

I2I_2

B

IO4−IO_4^-

C

IO3−IO_3^-

D

IO−IO^-

Step-by-Step Solution

Potassium permanganate (KMnO4KMnO_4) acts as a strong oxidising agent. Its reaction product with iodide depends on the pH of the medium:

  1. In acidic medium: Iodide (I−I^-) is oxidised to iodine (I2I_2).
  2. In neutral or faintly alkaline solution: Iodide (I−I^-) is oxidised to iodate (IO3−IO_3^-). The manganese is reduced from +7 (MnO4−MnO_4^-) to +4 (MnO2MnO_2).

The specific reaction equation provided in the NCERT text is: 2MnO4−+H2O+I−→2MnO2+2OH−+IO3−2MnO_4^- + H_2O + I^- \rightarrow 2MnO_2 + 2OH^- + IO_3^-

Exam Context & Concepts Covered

This question aligns with the NEET CHEMISTRY syllabus, specifically targeting concepts from The d-and f-Block Elements. Mastering this topic is crucial for scoring well in the upcoming medical entrance examinations. Solving conceptually related problems will help you understand the nuances of these concepts and improve your problem-solving speed.

CHEMISTRYThe d-and f-Block Elementsneutralfaintlyalkalinetreatedpotassium

More The d-and f-Block Elements Questions

View all

The $E^\circ$ value for the $Mn^{3+}/Mn^{2+}$ couple is more positive than that of $Cr^{3+}/Cr^{2+}$ or $Fe^{3+}/Fe^{2+}$ due to change of:

A.$d^5$ to $d^2$ configuration
B.$d^4$ to $d^5$ configuration
C.$d^3$ to $d^5$ configuration
D.$d^5$ to $d^4$ configuration
MediumSolve

The catalytic activity of transition metals is due to:

A.High enthalpy of atomization
B.Paramagnetic behaviour
C.Colour of hydrated ions
D.Variable oxidation states
EasySolve

The manganate and permanganate ions are tetrahedral, due to:

A.The π-bonding involves the overlap of d-orbitals of oxygen with d-orbitals of manganese.
B.The π-bonding involves the overlap of p-orbitals of oxygen with d-orbitals of manganese.
C.Absence of π-bonding.
D.The π-bonding involves the overlap of p-orbitals of oxygen with p-orbitals of manganese.
MediumSolve

The incorrect statement among the following is:

A.Lanthanoids are good conductors of heat and electricity.
B.Actinoids are highly reactive metals, especially when finely divided.
C.Actinoid contraction is greater for element to element than Lanthanoid contraction.
D.Most of the trivalent Lanthanoid ions are colourless in the solid-state.
MediumSolve

Identify the incorrect statement among the following:

A.There is a decrease in the radii of the atoms or ions as one proceeds from $\text{La}$ to $\text{Lu}$.
B.Lanthanoid contraction is the accumulation of successive shrinkages.
C.As a result of lanthanoid contraction, the properties of 4d series of the transition elements have no similarities with the 5d series of elements.
D.Shielding power of 4f electrons is quite weak.
MediumSolve

Acidified $K_2Cr_2O_7$ solution turns green when $Na_2SO_3$ is added to it. This is due to the formation of:

A.$CrO_4^{2-}$
B.$Cr_2(SO_3)_3$
C.$CrSO_4$
D.$Cr_2(SO_4)_3$
MediumSolve

Which of the following ions will exhibit colour in aqueous solutions?

A.$La^{3+} (Z=57)$
B.$Ti^{3+} (Z=22)$
C.$Lu^{3+} (Z=71)$
D.$Sc^{3+} (Z=21)$
EasySolve

Which of the following ions displays the d-d transition and paramagnetism?

A.$\text{CrO}_4^{2-}$
B.$\text{Cr}_2\text{O}_7^{2-}$
C.$\text{MnO}_4^-$
D.$\text{MnO}_4^{2-}$
MediumSolve

Why 32,000+ students choose TopperSquare

Everything you need to crack NEET

15,000+ Chapter MCQs

Physics, Chemistry, Biology — chapter-wise, topic-wise practice

AI Performance Analytics

Know your weak topics. Get a personalised study plan.

Full NEET Mock Tests

180 questions, timed, with detailed score analysis

PYQ Sets 2010–2024

15 years of past papers with solved explanations

Start Practising Free

No credit card · 30-second signup · Free forever plan included

This neet chemistry practice question is part of the TopperSquare free question bank. TopperSquare offers 15,000+ chapter-wise NEET MCQs across Physics, Chemistry, and Biology with detailed step-by-step explanations, full mock tests, NEET PYQs (2010–2024), and an AI-powered performance analytics dashboard. browse all neet practice questions → · practice chemistry sets →

Explore more subjects:Physics MCQs•Chemistry MCQs•Biology MCQs•Botany MCQs•Zoology MCQs•NEET Mock Tests•NEET PYQs
When neutral or faintly alkaline $KMnO_4$ is treat... | NEET MCQ | TopperSquare