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प्रश्न
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:
Oxidation states
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उत्तर १
Elements in the same horizontal group generally show the same number of oxidation states. The number of oxidation states shown by elements in the middle of each series is maximum, while those at the end are minimum.
उत्तर २
Elements have varying oxidation states in both series. The highest oxidation state corresponds to the total amount of electrons in ‘s’ and ‘d’ orbitals. The 5d transition series shows fewer oxidation states than the 4d series. In the 3d series, +2 and +3 oxidation states are common, resulting in stable complexes. In other series, OsO4 and PtF6 are stable at higher oxidation states.
संबंधित प्रश्न
Why do interstitial compounds have higher melting points than corresponding pure metals?
Complete the following chemical equations:
`(i) Cr_2O_7^(2-)+6Fe^(2+)+14H^+ ->`
`(ii) 2CrO_4^(2-)+2H^+ ->`
`(iii) 2MnO_4^-+5C_2O_4^(2-)+16H^+ ->`
The elements of 3d transition series are given as: Sc Ti V Cr Mn Fe Co
Answer the following: Write the element which shows maximum number of oxidation states. Give reason.
The elements of 3d transition series are given as: Sc Ti V Cr Mn Fe Co
Answer the following: Which element shows only +3 oxidation state?
How would you account for the following : Transition metals form coloured compounds
Which of the 3d series of the transition metals exhibits the largest number of oxidation states and why?
How would you account for the following:
The d1 configuration is very unstable in ions.
NF3 is possible, but NF5 is not. Why?
Why does the density of transition elements increase from Titanium to Copper? (at. no. Ti = 22, Cu = 29)
Why do transition metals exhibit higher enthalpy of atomization?
Transition elements form binary compounds with halogens. Which of the following elements will form \[\ce{MF3}\] type compounds?
(i) \[\ce{Cr}\]
(ii) \[\ce{Co}\]
(iii) \[\ce{Cu}\]
(iv) \[\ce{Ni}\]
Assertion (A): Cu cannot liberate hydrogen from acids.
Reason (R): Because it has positive electrode potential.
Answer the following question:
Which element of the first transition series has highest second ionisation enthalpy?
Account for the following:
In case of transition elements, ions of the same charge in a given series show progressive decrease in radius with increasing atomic number.
The element with atomic number 46 belongs to
Among the following pairs of ions, the lower oxidation state in aqueous solution is more stable than the other in:-
The basic character of transition metals monoxide follow the order.
How is the variability in oxidation states of transition metals different from that of p-block elements?
The second ionization enthalpies of chromium and manganese are 1592 and 1509 kJ/mol respectively. Explain the lower value of Mn.
Describe the oxidising action of potassium dichromate and write the ionic equation for its reaction with iron (II) solution.
