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प्रश्न
Why is the highest oxidation state of a metal exhibited in its oxide or fluoride only?
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उत्तर
Due to its small size and high electronegativities, oxygen or fluorine elements can oxidize the metal to its higher oxidation state.
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संबंधित प्रश्न
Why +2 oxidation state of manganese is more stable?
Give reasons:
Transition metals show variable oxidation states.
How would you account for the following : Transition metals form coloured compounds
How would you account for the following:
Of the d4 species, Cr2+ is strongly reducing while manganese (III) is strongly oxidising.
An analysis shows that FeO has a non-stoichiometric composition with formula Fe0.95O. Give reason.
Transition metals with highest melting point 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.
The magnetic nature of elements depends on the presence of unpaired electrons. Identify the configuration of transition element, which shows highest magnetic moment.
Which of the following ions show higher spin only magnetic moment value?
(i) \[\ce{Ti^3+}\]
(ii) \[\ce{Mn2+}\]
(iii) \[\ce{Fe2+}\]
(iv) \[\ce{Co3+}\]
Explain why does colour of KMnO4 disappear when oxalic acid is added to its solution in acidic medium.
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 any three processes where transition metals act as catalysts.
Which does not belong to first transition series?
The disproportionation of \[\ce{MnO^{2-}_4}\] in acidic medium resulted in the formation of two manganese compounds A and B. If the oxidation state of Mn in B is smaller than that of A, then the spin-only magnetic moment (µ) value of B in BM is ______. (Nearest integer)
Account for the following:
Copper has an exceptionally positive `"E"_("M"^(2+)//"M")^0` value.
A pair of coloured ions is ______.
The compounds of \[\ce{Ti^4+}\] ions are colourless due to ______.
Give a reason for the following:
Zinc, cadmium and mercury are considered as d-block elements but not regarded as transition elements.
A coordination compound has the formula \[\ce{CoCl3.4NH3}\]. It precipitates silver ions as AgCl and its molar conductance corresponds to a total of two ions.
Based on this information, answer the following question:
- Deduce the structural formula of the complex compound.
- Write the IUPAC name of the complex compound.
- Draw the geometrical isomers of the complex compound.
Decide which of the following atomic numbers are the atomic numbers of the inner transition elements:
29, 59, 74, 95, 102, 104
