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प्रश्न
Out of \[\ce{Cu2Cl2}\] and \[\ce{CuCl2}\], which is more stable and why?
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उत्तर
\[\ce{CuCl2}\] is more stable than \[\ce{Cu2Cl2}\] . The stability of \[\ce{CuCl2}\] is because of high enthalpy of hydration of \[\ce{Cu^2+ (aq)}\] than that of \[\ce{Cu+ (aq)}\].
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संबंधित प्रश्न
Give reasons:
Transition metals show variable oxidation states.
Out of Mn3+ and Cr3+, which is more paramagnetic and why ?
(Atomic nos. : Mn = 25, Cr = 24)
Why is the highest oxidation state of a metal exhibited in its oxide or fluoride only?
What may be the stable oxidation state of the transition element with the following d electron configuration in the ground state of its atom?
3d3
Write the factors which are related to the colour of transition metal ions.
How would you account for the following?
Zr (Z = 40) and Hf (Z = 72) have almost identical radii.
Account for the following :
Ti4+ is colourless whereas V4+ is coloured in an aqueous solutions.
Read the passage given below and answer the following question:
The transition metals when exposed to oxygen at low and intermediate temperatures form thin, protective oxide films of up to some thousands of Angstroms in thickness. Transition metal oxides lie between the extremes of ionic and covalent binary compounds formed by elements from the left or right side of the periodic table. They range from metallic to semiconducting and deviate by both large and small degrees from stoichiometry. Since electron bonding levels are involved, the cations exist in various valence states and hence give rise to a large number of oxides. The crystal structures are often classified by considering a cubic or hexagonal close-packed lattice of one set of ions with the other set of ions filling the octahedral or tetrahedral interstices. The actual oxide structures, however, generally show departures from such regular arrays due in part to distortions caused by packing of ions of different size and to ligand field effects. These distortions depend not only on the number of d-electrons but also on the valence and the position of the transition metal in a period or group.
In the following questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices on the basis of the above passage.
Assertion: Transition metals form protective oxide films.
Reason: Oxides of transition metals are always stoichiometric.
Which of the following ions show higher spin only magnetic moment value?
(i) \[\ce{Ti^3+}\]
(ii) \[\ce{Mn2+}\]
(iii) \[\ce{Fe2+}\]
(iv) \[\ce{Co3+}\]
Transition elements show high melting points. Why?
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.
Answer the following question:
Which element of the first transition series has highest second ionisation enthalpy?
The complex showing a spin-span magnetic moment of 2.82 B.M. is :-
The basic character of transition metals monoxide follow the order.
Which of the following transition metal is not coloured?
Why Zn, Cd and Hg are not called transition metals?
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.
Explain the magnetic properties of d-block (or transition) elements.
Decide which of the following atomic numbers are the atomic numbers of the inner transition elements:
29, 59, 74, 95, 102, 104
