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प्रश्न
Why EΘ values for Mn, Ni and Zn are more negative than expected?
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उत्तर
Negative E° values of Mn2+ and Zn2+ are because of stabilities of half-filled (3d10 : Mn2+) and fully-filled (3d10 : Zn2+) configuration respectively.Mn2+ ion has higher EΘ value because of highest negative enthalpy of hydrogen.
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संबंधित प्रश्न
Which of the following cations are coloured in aqueous solutions and why ?
Sc3+, V3+, Ti4+, Mn2+ (At. Nos. Sc = 21, V = 23, Ti = 22, Mn = 25)
The elements of 3d transition series are given as: Sc Ti V Cr Mn Fe Co
Answer the following: Which element shows only +3 oxidation state?
Out of Mn3+ and Cr3+, which is more paramagnetic and why ?
(Atomic nos. : Mn = 25, Cr = 24)
What may be the stable oxidation state of the transition element with the following d electron configurations in the ground state of its atom?
3d3
Predict which of the following will be coloured in the aqueous solution?
Ti3+, V3+, Cu+, Sc3+, Mn2+, Fe3+ and Co2+. Give reasons for each.
Which one of the following ions is coloured?
Which is the most stable oxidation state of iron?
Generally transition elements form coloured salts due to the presence of unpaired electrons. Which of the following compounds will be coloured in solid-state?
Match the solutions given in Column I and the colours given in Column II.
| Column I (Aqueous solution of salt) |
Column II (Colour) |
| (i) \[\ce{FeSO2.7H2O}\] | (a) Green |
| (ii) \[\ce{NiCl2.4H2O}\] | (b) Light pink |
| (iii) \[\ce{MnCl2.4H2O}\] | (c) Blue |
| (iv) \[\ce{CoC12,6H2O}\] | (d) Pale green |
| (v) \[\ce{Cu2 Cl2}\] | (e) Pink |
| (f) Colourless |
Assertion: The highest oxidation state of osmium is +8.
Reason: Osmium is a 5d-block element.
The standard electrode potentials of four elements A, B, C and D are – 3.05, – 1.66, – 0.40 and + 0.80. The highest chemical reactivity will be exhibited by
The spin magnetic moment of cobalt in the compound Hg [Co(SCN)4] is:-
A complex in which dsp2 hybridisation takes place is ______.
Match List - I with List - II.
| List - I | List - II | ||
| (A) | [Fe(CN)6]3− | (i) | 5.92 BM |
| (B) | [Fe(H2O)6]3+ | (ii) | 0 BM |
| (C) | [Fe(CN)6]4− | (iii) | 4.90 BM |
| (D) | [Fe(H2O)6]2+ | (iv) | 1.73 BM |
Choose the correct answer from the options given below.
Why are all copper halides known except that copper iodide?
Why Zn, Cd and Hg are not called transition metals?
In the ground state of atomic Fe (Z = 26), the spin-only magnetic moment is ______ × 10-1 BM.
(Round off to the nearest integer).
[Given: `sqrt3 = 1.73, sqrt2 = 1.41`]
Account for the following:
Eu2+ with electronic configuration [Xe]4f76s2 is a strong reducing agent.
Give a reason for the following:
Zinc, cadmium and mercury are considered as d-block elements but not regarded as transition elements.
Why are interstitial compounds well known for transition metals?
