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प्रश्न
Explain why is Fe3+ more stable than Fe2+?
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उत्तर
Electronic configuration of Fe2+ : 1s2 2s2 2p6 3s2 3p6 3d6
Electronic configuration of Fe3+ : 1s2 2s2 2p6 3s2 3p6 3d5
Due to the presence of half filled ‘d’ orbital, Fe3+ is more stable than Fe2+.
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संबंधित प्रश्न
Account for the following:
Cu+2 salts are coloured, while Zn2+ salts are white.
|
`E_((M^(2+)/M)` |
Cr | Mn | Fe | Co | Ni | Cu |
| -0.91 | -1.18 | -0.44 | -0.28 | -0.25 | -0.34 |
From the given data of E0 values, answer the following questions :
(1) Why is `E_(((Cu^(2+))/(Cu)))` value exceptionally positive
(2) Why is `E_(((Mn^(2+))/(Mn)))` value is highly negative as compared to other elements
(3) Which is the stronger reducing agents Cr2+ or Fe2+ ? Give Reason.
Account for the following:
Zn is not considered as a transition element.
Calculate the ‘spin only’ magnetic moment of \[\ce{M^{2+}_{( aq)}}\] ion (Z = 27).
How is the variability in oxidation states of transition metals different from that of the non-transition metals? Illustrate with examples.
Describe the oxidising action of potassium dichromate and write the ionic equation for its reaction with iodide.
What are alloys?
Comment on the statement that elements of the first transition series possess many properties different from those of heavier transition elements.
Following are the transition metal ions of 3d series:
Ti4+, V2+, Mn3+, Cr3+
(Atomic numbers: Ti = 22, V = 23, Mn = 25, Cr = 24)
Answer the following:
1) Which ion is most stable in an aqueous solution and why?
2) Which ion is a strong oxidising agent and why?
3) Which ion is colourless and why?
Give reasons Iron has the higher enthalpy of atomization than that of copper.
Which among the following transition metal has the lowest melting point?
In lake test for Al3+ ions, there is the formation of coloured ‘floating lake’. It is due to ______.
Metallic radii of some transition elements are given below. Which of these elements will have highest density?
| Element | \[\ce{Fe}\] | \[\ce{Co}\] | \[\ce{Ni}\] | \[\ce{Cu}\] |
| Metallic radii/pm | 126 | 125 | 125 | 128 |
The magnetic nature of elements depends on the presence of unpaired electrons. Identify the configuration of transition element, which shows highest magnetic moment.
Out of \[\ce{Cu2Cl2}\] and \[\ce{CuCl2}\], which is more stable and why?
Reactivity of transition elements decreases almost regularly from Sc to Cu. Explain.
Match the catalysts given in Column I with the processes given in Column II.
| Column I (Catalyst) | Column II (Process) |
| (i) \[\ce{Ni}\] in the presence of hydrogen | (a) Zieglar Natta catalyst |
| (ii) \[\ce{Cu2C12}\] | (b) Contact process |
| (iii) \[\ce{V2O5}\] | (c) Vegetable oil to ghee |
| (iv) Finely divided iron | (d) Sandmeyer reaction |
| (v) \[\ce{TiCl4 + Al (CH3)3}\] | (e) Haber's Process |
| (f) Decomposition of KCIO3 |
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 |
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) \[\ce{Ni}\] |
Assertion: \[\ce{Cu^2+}\] iodide is not known.
Reason: \[\ce{Cu^2+}\] oxidises \[\ce{I^-}\] to iodine.
On the basis of the figure given below, answer the following questions:
- Why Manganese has lower melting point than Chromium?
- Why do transition metals of 3d series have lower melting points as compared to 4d series?
- In the third transition series, identify and name the metal with the highest melting point.
Which of the following transition metal is not coloured?
Account for the following:
Transition metals form alloys.
Which of the following ions acts as a typical transition metal ion?
Which of the following characteristics of transition metals is associated with their catalytic activity?
The given graph shows the trends in melting points of transition metals:
Explain the reason why Cr has the highest melting point and manganese (Mn) has a lower melting point.
Write the number of unpaired electrons in Cr3+.
(Atomic number of Cr = 24)
Account for the following:
Eu2+ with electronic configuration [Xe]4f76s2 is a strong reducing agent.
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:
Atomic sizes
‘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:
