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कर्नाटक बोर्ड पी.यू.सी.पीयूसी विज्ञान 2nd PUC Class 12

Assertion: CuX2+ iodide is not known. Reason: CuX2+ oxidises IX− to iodine.

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प्रश्न

Assertion: \[\ce{Cu^2+}\] iodide is not known.

Reason: \[\ce{Cu^2+}\] oxidises \[\ce{I^-}\] to iodine.

विकल्प

  • Both assertion and reason are true, and reason is the correct explanation of the assertion.

  • Both assertion and reason are true but reason is not the correct explanation of assertion.

  • Assertion is not true but reason is true.

  • Both assertion and reason are false.

MCQ
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उत्तर

Both assertion and reason are true, and reason is the correct explanation of the assertion.

Explanation:

All halogens combine with copper to form copper halides except iodine. The reason behind this is that \[\ce{Cu^2+}\] oxidises iodide (-1) to iodine (0). Therefore, \[\ce{Cu^2+}\] iodide does not exist .Both the statements assertion and reason are correct and reason is the correct explanation of assertion.  

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अध्याय 8: The d-and f-Block Elements - Multiple Choice Questions (Type - I) [पृष्ठ ११४]

APPEARS IN

एनसीईआरटी एक्झांप्लर Chemistry Exemplar [English] Class 12
अध्याय 8 The d-and f-Block Elements
Multiple Choice Questions (Type - I) | Q 59 | पृष्ठ ११४

संबंधित प्रश्न

Which is a stronger reducing agent, Cr2+ or Fe2+ and why?


Compare the stability of +2 oxidation state for the elements of the first transition series.


Which metal in the first series of transition metals exhibits +1 oxidation state most frequently and why?


How would you account for the following? 

Zr (Z = 40) and Hf (Z = 72) have almost identical radii.

 


Give reasons Iron has the higher enthalpy of atomization than that of copper.


The transition metals show _________ character because of the presence of unpaired· electrons and Cu+ is ____________ because of its electronic configuration is [Ar]3d10


How is potassium dichromate prepared from chrome iron ore?


Transition metals with lowest melting point is ______.


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: Cations of transition elements occur in various valence states.

Reason: Large number of oxides of transition elements are possible.


\[\ce{KMnO4}\] acts as an oxidising agent in acidic medium. The number of moles of \[\ce{KMnO4}\] that will be needed to react with one mole of sulphide ions in acidic solution is ______.


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) \[\ce{Ni}\]

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.


On the basis of the figure given below, answer the following questions:

  1. Why Manganese has lower melting point than Chromium?
  2. Why do transition metals of 3d series have lower melting points as compared to 4d series?
  3. In the third transition series, identify and name the metal with the highest melting point.

Give reasons for the following statement:

Transition metals and most of their compounds show paramagnetic behaviour.


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 number of terminal oxygen atoms present in the product B obtained from the following reactions is:

\[\ce{FeCr2O4 + Na2CO3 + O2 -> A + Fe2O3 + CO2}\]

\[\ce{A + H^+ -> B + H2O + Na^+}\]


A transition element X has an electronic configuration [Ar]4s23d3. Predict its likely oxidation states.


Write the ionic equation for reaction of KI with acidified KMnO4.


Give a reason for the following.

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


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