Advertisements
Advertisements
प्रश्न
Why EΘ values for Mn, Ni and Zn are more negative than expected?
Advertisements
उत्तर
Negative E° values of Mn2+ and Zn2+ are because of stabilities of half-filled (3d10 : Mn2+) and fully-filled (3d10 : Zn2+) configuration respectively.Mn2+ ion has higher EΘ value because of highest negative enthalpy of hydrogen.
APPEARS IN
संबंधित प्रश्न
ln which pair highest oxidation states of transition metals are found:
Account for the following:
Cr2+ is a strong reducing agent.
How would you account for the following: Transition metals form complex compounds.
Account for the following:
E° value for the Mn3+/Mn2+ couple is much more positive than that for Cr3+/Cr2+.
Calculate the ‘spin only’ magnetic moment of \[\ce{M^{2+}_{ (aq)}}\] ion (Z = 27).
Use Hund’s rule to derive the electronic configuration of Ce3+ ion and calculate its magnetic moment on the basis of ‘spin-only’ formula.
Complete and balance the following chemical equations
`MnO_4^(-) + H_2O + I^(-) ->`
Account for the following :
Ti4+ is colourless whereas V4+ is coloured in an aqueous solutions.
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 |
Interstitial compounds are formed when small atoms are trapped inside the crystal lattice of metals. Which of the following is not the characteristic property of interstitial compounds?
Transition elements show high melting points. Why?
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.
Mention the type of compounds formed when small atoms like H, C and N get trapped inside the crystal lattice of transition metals. Also give physical and chemical characteristics of these compounds.
It has been observed that first ionization energy of 5 d series of transition elements are higher than that of 3d and 4d series, explain why?
Give reasons for the following statement:
Transition metals and most of their compounds show paramagnetic behaviour.
Which of the following transition metals shows +1 and +2 oxidation states?
A transition element X has an electronic configuration [Ar]4s23d3. Predict its likely oxidation states.
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.
Describe the oxidising action of potassium dichromate and write the ionic equation for its reaction with H2S.
