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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).`


Account for the following:

Cu+2 salts are coloured, while Zn2+ salts are white.


What are the transition elements? Write two characteristics of the transition elements.


The `E_((M^(2+)//M))^Θ` value for copper is positive (+0.34 V). What is possibly the reason for this? (Hint: consider its high ΔaHΘ and low ΔhydHΘ)


Explain briefly how +2 state becomes more and more stable in the first half of the first row transition elements with increasing atomic number?


Explain why transition elements form alloys.


Which is the most stable oxidation state of iron?


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.


Why does copper not replace hydrogen from acids?


A solution of \[\ce{KMnO4}\] on reduction yields either a colourless solution or a brown precipitate or a green solution depending on pH of the solution. What different stages of the reduction do these represent and how are they carried out?


Match the properties given in Column I with the metals given in Column II.

  Column I (Property) Column II (Metal)
(i) Element with highest second
ionisation enthalpy
(a) \[\ce{Co}\]
(ii) Element with highest
third ionisation enthalpy
(b) \[\ce{Cr}\]
(iii) \[\ce{M}\] in \[\ce{M(CO)6}\] is (c) \[\ce{Cu}\]
(iv) Element with highest heat
of atomisation
(d) \[\ce{Zn}\]
    (e) \[\ce{Ni}\]

Give reason for the following statement:

Physical and chemical properties of the 4d and 5d series of the transition elements are quite similar to expected.


The oxidation state of Fe in [Fe(CO)5] is ______.


Which of the following characteristics of transition metals is associated with their catalytic activity?


Which of the following transition metals shows +1 and +2 oxidation states?


Give a reason for the following:

Transition metals possess a great tendency to form complex compounds.


Describe the oxidising action of potassium dichromate and write the ionic equation for its reaction with H2S.


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