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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.
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संबंधित प्रश्न
How would you account for the following:
The d1 configuration is very unstable in ions.
Which one of the following ions is coloured?
Why do transition metal ions possess a great tendency to form complexes?
Generally transition elements form coloured salts due to the presence of unpaired electrons. Which of the following compounds will be coloured in solid-state?
When \[\ce{KMnO4}\] solution is added to oxalic acid solution, the decolourisation is slow in the beginning but becomes instantaneous after some time because ______.
Which of the following statements is not correct?
Highest oxidation state of manganese in fluoride is \[\ce{+4 (MnF4)}\] but highest oxidation state in oxides is \[\ce{+7 (Mn2O7)}\] because ______.
Why is \[\ce{HCl}\] not used to make the medium acidic in oxidation reactions of \[\ce{KMnO4}\] in acidic medium?
Out of \[\ce{Cu2Cl2}\] and \[\ce{CuCl2}\], which is more stable and why?
Assertion (A): Cu cannot liberate hydrogen from acids.
Reason (R): Because it has positive electrode potential.
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.
Identify the metal and justify your answer.
Carbonyl \[\ce{M(CO)5}\]
Transition metals can act as catalysts because these can change their oxidation state. How does \[\ce{Fe(III)}\] catalyse the reaction between iodide and persulphate ions?
Which of the following is non-metallic?
The standard electrode potentials of four elements A, B, C and D are – 3.05, – 1.66, – 0.40 and + 0.80. The highest chemical reactivity will be exhibited by
Which of the following maxm magnetic moment?
Why are all copper halides known except that copper iodide?
Account for the following:
Zirconium (Zr) and Hafnium (Hf) are difficult to separate.
A coordination compound has the formula \[\ce{CoCl3.4NH3}\]. It precipitates silver ions as AgCl and its molar conductance corresponds to a total of two ions.
Based on this information, answer the following question:
- Deduce the structural formula of the complex compound.
- Write the IUPAC name of the complex compound.
- Draw the geometrical isomers of the complex compound.
