Advertisements
Advertisements
प्रश्न
Which one of the following ions is coloured?
पर्याय
Se3+
Ti4+
Zn2+
V2+
Advertisements
उत्तर
V2+
Explanation:
The V2+ ion has an unpaired electron while the others have paired electrons.
So, `sqrt(2+)` is a coloured ion.
APPEARS IN
संबंधित प्रश्न
Why do the transition elements have higher enthalpies of atomisation?
In 3d series (Sc to Zn), which element has the lowest enthalpy of atomisation and why?
Out of Mn3+ and Cr3+, which is more paramagnetic and why ?
(Atomic nos. : Mn = 25, Cr = 24)
In the series Sc (Z = 21) to Zn (Z = 30), the enthalpy of atomization of zinc is the lowest, i.e., 126 kJ mol−1. Why?
The `E_((M^(2+)//M))^Θ` value for copper is positive (+0.34 V). What is possibly the reason for this? (Hint: consider its high ΔaHΘ and low ΔhydHΘ)
Explain briefly how +2 state becomes more and more stable in the first half of the first row transition elements with increasing atomic number?
What are the characteristics of the transition elements and why are they called transition elements?
What are alloys?
Dissociation of H2S is suppressed in acidic medium.
How is potassium dichromate prepared from chrome iron ore?
Explain why transition elements form alloys.
Electronic configuration of a transition element X in +3 oxidation state is [Ar]3d5. What is its atomic number?
When acidified \[\ce{K2Cr2O7}\] solution is added to \[\ce{Sn^{2+}}\] salts then \[\ce{Sn^{2+}}\] changes to ______.
Which of the following ions show higher spin only magnetic moment value?
(i) \[\ce{Ti^3+}\]
(ii) \[\ce{Mn2+}\]
(iii) \[\ce{Fe2+}\]
(iv) \[\ce{Co3+}\]
The second and third rows of transition elements resemble each other much more than they resemble the first row. Explain why?
Assertion: Separation of \[\ce{Zr}\] and \[\ce{Hf}\] is difficult.
Reason: Because \[\ce{Zr}\] and \[\ce{Hf}\] lie in the same group of the periodic table.
When a chromite ore (A) is fused with sodium carbonate in free excess of air and the product is dissolved in water, a yellow solution of compound (B) is obtained. After treatment of this yellow solution with sulphuric acid, compound (C) can be crystallised from the solution. When compound (C) is treated with KCl, orange crystals of compound (D) crystallise out. Identify A to D and also explain the reactions.
Fill in the blanks by choosing the appropriate word(s) from those given in the brackets:
(activation energy, Threshold energy, increased, lowered, partially, full, d-d transition, Benzoic acid, benzaldehyde)
Only those transition metal ions will be coloured which have ______ filled d-orbitals facilitating ______.
Why are fluorides of transition metals more stable in their higher oxidation state as compared to the lower oxidation state?
A metallic ion 'M' reacts with chloride ion to form white precipitate which is readily soluble in aqueous ammonia. Identify 'M'?
The orientation of an atomic orbital is governed by
Agcl is soluble in NH4OH. The solubility is due to the information of:-
Why are all copper halides known except that copper iodide?
The value of Δ0 for \[\ce{RhCl^{3-}6}\] is 243 KJ/mol which wavelength of light will promote an electron from. The colour of the complex is ______.
Assertion (A): Transition metals have high enthalpy of atomisation.
Reason (R): Greater number of unpaired electrons in transition metals results in weak metallic bonding.
Account for the following:
Eu2+ with electronic configuration [Xe]4f76s2 is a strong reducing agent.
For M2+/M and M3+/M2+systems, the EΘ values for some metals are as follows:
| Cr2+/Cr | −0.9 V |
| Mn2+/Mn | −1.2 V |
| Fe2+/Fe | −0.4 V |
| Cr3/Cr2+ | −0.4 V |
| Mn3+/Mn2+ | +1.5 V |
| Fe3+/Fe2+ | +0.8 V |
Use this data to comment upon:
The ease with which iron can be oxidised as compared to a similar process for either chromium or manganese metal.
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:
Ionisation enthalpies
