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प्रश्न
Why is the highest oxidation state of a metal exhibited in its oxide or fluoride only?
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उत्तर
Due to its small size and high electronegativities, oxygen or fluorine elements can oxidize the metal to its higher oxidation state.
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संबंधित प्रश्न
Why is Sc3+ colourless while Ti3+ coloured? (Atomic number Sc = 21, Ti =22)
Account for the following:
Zn is not considered as a transition element.
To what extent do the electronic configurations decide the stability of oxidation states in the first series of the transition elements? Illustrate your answer with examples.
Following are the transition metal ions of 3d series:
Ti4+, V2+, Mn3+, Cr3+
(Atomic numbers: Ti = 22, V = 23, Mn = 25, Cr = 24)
Answer the following:
1) Which ion is most stable in an aqueous solution and why?
2) Which ion is a strong oxidising agent and why?
3) Which ion is colourless and why?
Write balanced chemical equations for the conversion of `CrO_4^(2-)` to `Cr_2O_7^(2-)` in acidic medium and `Cr_2O_7^(2-)` to `CrO_4^(2-)`
in basic medium.
Explain why Zn2+ salts are white whereas Cu2+ salts are coloured.
Which of the following will not act as oxidising agents?
(i) \[\ce{CrO3}\]
(ii) \[\ce{MoO3}\]
(iii) \[\ce{WO3}\]
(iv) \[\ce{CrO^{2-}4}\]
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.
Although fluorine is more electronegative than oxygen, but the ability of oxygen to stabilise higher oxidation states exceeds that of fluorine. Why?
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.
Mention any three processes where transition metals act as catalysts.
Agcl is soluble in NH4OH. The solubility is due to the information of:-
Which of the following ions will exhibit colour in aqueous solution?
Account for the following:
Transition metals form alloys.
Which of the following characteristics of transition metals is associated with their catalytic activity?
Assertion (A): Transition metals have high enthalpy of atomisation.
Reason (R): Greater number of unpaired electrons in transition metals results in weak metallic bonding.
The second ionization enthalpies of chromium and manganese are 1592 and 1509 kJ/mol respectively. Explain the lower value of Mn.
Give a reason for the following.
Some transition metals and their compounds get attracted towards the magnetic field.
Describe the oxidising action of potassium dichromate and write the ionic equation for its reaction with iron (II) solution.
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
