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प्रश्न
Give reason for the following statement:
Physical and chemical properties of the 4d and 5d series of the transition elements are quite similar to expected.
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उत्तर
Physical and chemical properties of 4d and 5d series elements are similar because they have same atomic and ionic radii due to the lanthanide contraction. Due to equal atomic radii the size of Zr and Hf, Nb and Ta, Mo and W, etc., the two elements of each pair have the same properties.
संबंधित प्रश्न
Out of Mn3+ and Cr3+, which is more paramagnetic and why ?
(Atomic nos. : Mn = 25, Cr = 24)
An analysis shows that FeO has a non-stoichiometric composition with formula Fe0.95O. Give reason.
Why do transition metals exhibit higher enthalpy of atomization?
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.
When a brown compound of manganese (A) is treated with \[\ce{HCl}\] it gives a gas (B). The gas taken in excess, reacts with \[\ce{NH3}\] to give an explosive compound (C). Identify compounds A, B and C.
A solution of \[\ce{KMnO4}\] on reduction yields either a colourless solution or a brown precipitate or a green solution depending on pH of the solution. What different stages of the reduction do these represent and how are they carried out?
A violet compound of manganese (A) decomposes on heating to liberate oxygen and compounds (B) and (C) of manganese are formed. Compound (C) reacts with KOH in the presence of potassium nitrate to give compound (B). On heating compound (C) with conc. \[\ce{H2SO4}\] and \[\ce{NaCl}\], chlorine gas is liberated and a compound (D) of manganese along with other products is formed. Identify compounds A to D and also explain the reactions involved.
Which of the following transition metal is not coloured?
The electrode potential of M2+/M of 3d-series elements shows the positive value for ______.
Account for the following:
Sc3+ is colourless whereas Ti3+ is coloured in an aqueous solution.
