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Why is HCl not used to make the medium acidic in oxidation reactions of KMnOX4 in acidic medium? - Chemistry

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प्रश्न

Why is \[\ce{HCl}\] not used to make the medium acidic in oxidation reactions of \[\ce{KMnO4}\] in acidic medium?

विकल्प

  • Both \[\ce{HCl}\] and \[\ce{KMnO4}\] act as oxidising agents.

  • \[\ce{KMnO4}\] oxidises \[\ce{HCl}\] into \[\ce{Cl2}\] which is also an oxidising agent.

  • \[\ce{KMnO4}\] is a weaker oxidising agent than \[\ce{HCl}\].

  • \[\ce{KMnO4}\] acts as a reducing agent in the presence of \[\ce{HCl}\].

MCQ
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उत्तर

\[\ce{KMnO4}\] oxidises \[\ce{HCl}\] into \[\ce{Cl2}\] which is also an oxidising agent.

Explanation:

\[\ce{HCl}\] is not used to make the medium acidic in oxidation reactions of \[\ce{KMnO4}\] in acidic medium. The reason is that if \[\ce{HCl}\] is used, the oxygen produced from \[\ce{KMnO4 + HCl}\] is partly utilized in oxidizing \[\ce{HCl}\] to \[\ce{Cl}\], which itself acts as an oxidizing agent and partly oxidises the reducing agent.

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अध्याय 8: The d-and f-Block Elements - Multiple Choice Questions (Type - I) [पृष्ठ १०९]

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एनसीईआरटी एक्झांप्लर Chemistry [English] Class 12
अध्याय 8 The d-and f-Block Elements
Multiple Choice Questions (Type - I) | Q 21 | पृष्ठ १०९

संबंधित प्रश्न

 
 
 

Complete the following chemical equations:

`(i) Cr_2O_7^(2-)+6Fe^(2+)+14H^+ ->`

`(ii) 2CrO_4^(2-)+2H^+ ->`

`(iii) 2MnO_4^-+5C_2O_4^(2-)+16H^+ ->`

 
 
 

Calculate magnetic moment of  `Fe_((aq))^(2+) ion (Z=26).`


The elements of 3d transition series are given as: Sc Ti V Cr Mn Fe Co

Answer the following: Which element is a strong oxidising agent in +3 oxidation state and why?


What may be the stable oxidation state of the transition element with the following d electron configurations in the ground state of its atom?

3d3


What can be inferred from the magnetic moment value of the following complex species?

Example Magnetic Moment (BM)
K2[MnCl4] 5.9

The paramagnetic character in the 3d-transition series elements increases up to Mn and then decreases.


Explain why transition elements form alloys.


Explain why transition metals and their compounds act as a catalyst.


Electronic configuration of Mn2+ is ____________.


Read the passage given below and answer the following question:

The transition metals when exposed to oxygen at low and intermediate temperatures form thin, protective oxide films of up to some thousands of Angstroms in thickness. Transition metal oxides lie between the extremes of ionic and covalent binary compounds formed by elements from the left or right side of the periodic table. They range from metallic to semiconducting and deviate by both large and small degrees from stoichiometry. Since electron bonding levels are involved, the cations exist in various valence states and hence give rise to a large number of oxides. The crystal structures are often classified by considering a cubic or hexagonal close-packed lattice of one set of ions with the other set of ions filling the octahedral or tetrahedral interstices. The actual oxide structures, however, generally show departures from such regular arrays due in part to distortions caused by packing of ions of different size and to ligand field effects. These distortions depend not only on the number of d-electrons but also on the valence and the position of the transition metal in a period or group.

In the following questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices on the basis of the above passage.

Assertion: Crystal structure of oxides of transition metals often show defects.

Reason: Ligand field effect cause distortions in crystal structures.


Electronic configuration of a transition element X in +3 oxidation state is [Ar]3d5. What is its atomic number?


The magnetic nature of elements depends on the presence of unpaired electrons. Identify the configuration of transition element, which shows highest magnetic moment.


The second and third rows of transition elements resemble each other much more than they resemble the first row. Explain why?


Mention the type of compounds formed when small atoms like H, C and N get trapped inside the crystal lattice of transition metals. Also give physical and chemical characteristics of these compounds.


Account for the following: 

In case of transition elements, ions of the same charge in a given series show progressive decrease in radius with increasing atomic number.


The element with atomic number 53 belongs to


Consider the following standard electrode potential values:

\[\ce{Sn^{2+}_{ (aq)} + 2e^- -> Sn_{(s)}}\]; E0 = −0.14 V

\[\ce{Fe^{3+}_{ (aq)} + e^- -> Fe^{2+}_{ (aq)}}\]; E0 = +0.77 V

What is the cell reaction and potential for the spontaneous reaction that occurs?


Give a reason for the following.

Some transition metals and their compounds get attracted towards the magnetic field.


Compare the general characteristics of the first series of the transition metals with those of the second and third series metals in the respective vertical columns. Give special emphasis on the following point:

Oxidation states


Compare the general characteristics of the first series of the transition metals with those of the second and third series metals in the respective vertical columns. Give special emphasis on the following point:

Ionisation enthalpies


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