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प्रश्न
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:
Electronic configurations
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उत्तर
The electronic configurations of the elements of the same group are generally similar.
The first transition series shows two exceptions:
Cr = 3d5 4s1 and Cu = 3d10 4s1
The second series shows more exceptions:
Mo (42) = 4d5 5s1, Tc (43) = 4d6 5s1, Ru (44) = 4d7 5s1, Rh (45) = 4d8 5s1, Pd (46) = 4d10 5s0, Ag (47) = 4d10 5s1
Similarly, the third series shows exceptions:
W (74) = 5d4 6s1, Pt (78) = 5d9 6s1, and Au (79) = 5d10 6s1
The first transition series gradually fills 3d-orbitals, whereas the second and third transition series gradually fill 4d-orbitals and 5d-orbitals, respectively. Therefore, in many cases in the horizontal series, the electronic configurations of the three series are not the same.
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संबंधित प्रश्न
Which metal in the first transition series (3d series) exhibits + 1 oxidation state most frequently and why?
How would you account for the following?
Transition metals exhibit variable oxidation states.
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?
Account for the following:
Cu+ ion is unstable in aqueous solution.
How would you account for the irregular variation of ionization enthalpies (first and second) in the first series of the transition elements?
Complete and balance the following chemical equations
`Fe^(2+) + MnO_4^(-) + H^+ ->`
Give reasons:
E° value for the Mn3+/Mn2+ couple is much more positive than that for Fe3+/Fe2+.
The paramagnetic character in the 3d-transition series elements increases up to Mn and then decreases.
Transition metals with lowest melting point is ______.
Which of the following ions show higher spin only magnetic moment value?
(i) \[\ce{Ti^3+}\]
(ii) \[\ce{Mn2+}\]
(iii) \[\ce{Fe2+}\]
(iv) \[\ce{Co3+}\]
Out of \[\ce{Cu2Cl2}\] and \[\ce{CuCl2}\], which is more stable and why?
The halides of transition elements become more covalent with increasing oxidation state of the metal. Why?
Reactivity of transition elements decreases almost regularly from Sc to Cu. Explain.
If enthalpies of formation of C2H4(g), CO2(g) and H2O(l) at 25°C and 1 atm pressure are 52, – 394 and – 286 kJ/mol respectively, the change in ethalpy for combustion of C2H4 is equal to
Why Zn, Cd and Hg are not called transition metals?
Which of the following ions acts as a typical transition metal ion?
Consider the following standard electrode potential values:
\[\ce{Fe^{3+}_{ (aq)} + e^- -> Fe^{2+}_{ (aq)}}\], E0 = +0.77 V
\[\ce{MnO^{-4}_{ (aq)} + 8H^+ + 5e^- -> Mn^{2+}_{ (aq)} + 4H2O_{(l)}}\], E0 = +1.51 V
What is the cell potential for the redox reaction?
Why are interstitial compounds well known for transition metals?
‘Spin only’ magnetic moment is the same for which of the following ions?
- Ti3+
- Cr2+
- Mn2+
- Fe2+
- Sc3+
Choose the most appropriate answer from the options given below:
