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प्रश्न
Which metal in the first series of transition metals exhibits +1 oxidation state most frequently and why?
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उत्तर
- Copper (Cu) in the first series of transition metals most frequently exhibits the +1 oxidation state.
- This occurs because Cu has the electronic configuration [Ar] 3d10 4s1.
- When Cu forms the +1 ion (Cu+), it achieves a completely filled and very stable 3d10 configuration.
- The extra stability of the filled d-subshell makes the +1 oxidation state common for copper compared to other first transition metals.
संबंधित प्रश्न
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?
Give reasons:
Transition metals show variable oxidation states.
What are the transition elements? Write two characteristics of the transition elements.
In the series Sc (Z = 21) to Zn (Z = 30), the enthalpy of atomization of zinc is the lowest, i.e., 126 kJ mol−1. Why?
How would you account for the irregular variation of ionization enthalpies (first and second) in the first series of the transition elements?
What may be the stable oxidation state of the transition element with the following d electron configuration in the ground state of its atom?
3d3
How is the variability in oxidation states of transition metals different from that of the non-transition metals? Illustrate with examples.
How is the variability in oxidation states of transition metals different from that of the non-transition metals? Illustrate with examples.
For M2+/M and M3+/M2+ systems, the E° values for some metals are as follows:
| Cr2+/Cr | −0.9 V |
| Mn2+/Mn | −1.2 V |
| Fe2+/Fe | −0.4 V |
| Cr3/Cr2+ | −0.4 V |
| Mn3+/Mn2+ | +1.5 V |
| Fe3+/Fe2+ | +0.8 V |
Use this data to comment upon:
- The stability of Fe3+ in acid solution as compared to that of Cr3+ or Mn3+ and
- the ease with which iron can be oxidised as compared to a similar process for either chromium or manganese metal.
Complete and balance the following chemical equations
`Fe^(2+) + MnO_4^(-) + H^+ ->`
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: Transition metals form protective oxide films.
Reason: Oxides of transition metals are always stoichiometric.
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?
The halides of transition elements become more covalent with increasing oxidation state of the metal. Why?
The spin magnetic moment of cobalt in the compound Hg [Co(SCN)4] is:-
Which one among the following metals of the 3d series has the lowest melting point?
Which of the following transition metals shows +1 and +2 oxidation states?
Write the number of unpaired electrons in Cr3+.
(Atomic number of Cr = 24)
Account for the following:
Copper has an exceptionally positive `"E"_("M"^(2+)//"M")^0` value.
Why are interstitial compounds well known for transition metals?
