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प्रश्न
Comment on the statement that elements of the first transition series possess many properties different from those of heavier transition elements.
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उत्तर १
- In the first transition series, lower oxidation states are more stable, while heavier transition elements have higher oxidation states.
- The 5d transition series exhibits higher ionization enthalpy compared to the 3d and 4d transition series.
- M-M bonding is prevalent in heavier transition metals, but less so in the first series.
- The elements in the first transition series do not form complexes with coordination numbers of 7 or 8.
- Elements in the first series can form high or low-spin complexes based on ligand strength, while those in the other series form low-spin complexes regardless of ligand strength.
उत्तर २
This statement is true. According to the heavier transition elements (elements of the second and third transition series), the elements of the first transition series have different atomic radii, melting and boiling temperatures, ionization enthalpies, atomization enthalpies, and other characteristics. Their mentioned characteristics have significantly lower values.
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संबंधित प्रश्न
In 3d series (Sc to Zn), which element has the lowest enthalpy of atomisation and why?
To what extent do the electronic configurations decide the stability of oxidation states in the first series of the transition elements? Illustrate your answer with examples.
What are the characteristics of the transition elements and why are they called transition elements?
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
Write down the number of 3d electrons in the following ion:
Cu2+
Indicate how would you expect the five 3d orbitals to be occupied for this hydrated ions (octahedral).
The paramagnetic character in the 3d-transition series elements increases up to Mn and then decreases.
Two metallic elements A and B have the following standard oxidation potentials: A = 0·40v B = - 0·80v. What would you expect if element A was added to an aqueous salt solution of element B? Give a reason for your answer.
Which of the following statements is not correct?
The halides of transition elements become more covalent with increasing oxidation state of the metal. Why?
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.
Catalytic hydrogenation of benzene gives
Photographic film and plates have - au essential ingredient of
Which of the following species has maximum magnetic momentum?
Which one of the following characters tie of the transition metal is associated with higher catalytic activity?
The number of terminal oxygen atoms present in the product B obtained from the following reactions is:
\[\ce{FeCr2O4 + Na2CO3 + O2 -> A + Fe2O3 + CO2}\]
\[\ce{A + H^+ -> B + H2O + Na^+}\]
Consider the following standard electrode potentials (E° in volts) in aqueous solution:
| Element | M3+/M | M+/M |
| Al | - 1.66 | +0.55 |
| Tl | + 1.26 | -0.34 |
Based on these data, which of the following statements is correct?
Which of the following characteristics of transition metals is associated with their catalytic activity?
Which property of transition metals enables them to behave as catalysts?
The trend of which property is represented by the following graph?
