Advertisements
Advertisements
प्रश्न
Why do the transition elements have higher enthalpies of atomisation?
Explain giving reasons:
The enthalpies of atomisation of the transition metals are high.
How would you account for the following?
The transition elements exhibit high enthalpies of atomization.
How would you account for the following:
The transition elements have high enthalpies of atomization?
Give reasons for the following:
Transition elements have high enthalpies of atomization.
Advertisements
उत्तर
- Transition elements have high enthalpies of atomization due to the presence of many unpaired electrons in their atoms.
- Unpaired electrons lead to strong interatomic interactions and stronger metallic bonding between atoms.
- The stronger the metallic bonds, the more energy is required to break these bonds, resulting in higher enthalpies of atomization.
- Elements of the second and third transition series have even higher enthalpies due to more frequent metal-metal bonding.
- This strong bonding also explains their high melting and boiling points.
APPEARS IN
संबंधित प्रश्न
Why is Sc3+ colourless while Ti3+ coloured? (Atomic number Sc = 21, Ti =22)
In 3d series (Sc to Zn), which element has the lowest enthalpy of atomisation and why?
How would you account for the following:
Cobalt (II) is stable in aqueous solutions, but in the presence of complexing reagents, it is easily oxidised.
What are alloys?
What are inner transition elements?
What can be inferred from the magnetic moment value of the following complex species?
| Example | Magnetic Moment (BM) |
| K2[MnCl4] | 5.9 |
Write the formula of an oxo-anion of Chromium (Cr) in which it shows the oxidation state equal to its group number
Complete and balance the following chemical equations
`MnO_4^(-) + H_2O + I^(-) ->`
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.
Maximum oxidation state is shown by ____________.
Transition elements show magnetic moment due to spin and orbital motion of electrons. Which of the following metallic ions have almost same spin only magnetic moment?
(i) \[\ce{Co^{2+}}\]
(ii) \[\ce{Cr^{2+}}\]
(iii) \[\ce{Mn^{2+}}\]
(iv) \[\ce{Cr^{3+}}\]
Why does copper not replace hydrogen from acids?
Answer the following question:
Which element of the first transition series has highest third ionisation enthalpy?
Mention any three processes where transition metals act as catalysts.
A metallic ion 'M' reacts with chloride ion to form white precipitate which is readily soluble in aqueous ammonia. Identify 'M'?
Catalytic hydrogenation of benzene gives
Passing H2S gas into a mixture of Mn2+ and Ni2+, Cu2+, ions in an acidified aqueous solution precipitates.
Account for the following:
Copper has an exceptionally positive `"E"_("M"^(2+)//"M")^0` value.
In order to protect iron from corrosion, which one will you prefer as a sacrificial electrode, Ni or Zn? Why? (Given standard electrode potentials of Ni, Fe and Zn are -0.25 V, -0.44 V and -0.76 V respectively.)
Give a reason for the following:
Zinc, cadmium and mercury are considered as d-block elements but not regarded as transition elements.
