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प्रश्न
Give an example and suggest a reason for the following feature of the transition metal chemistry:
A transition metal exhibits the highest oxidation state in oxides and fluorides.
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उत्तर
The highest oxidation states of transition metals are observed in oxides and fluorides. Because oxygen and fluorine are highly electronegative elements and small in size, they are strong oxidising agents. For example, chromium displays a +6 oxidation state in CrF6, and vanadium displays a +5 oxidation state in V2O5.
संबंधित प्रश्न
Complete the following equations: Cr2O72- + 14H+ + 6I →
Complete the following equation:
\[\ce{2MnO4- + 6H+ + 5NO2- ->}\]
When chromite ore FeCr2O4 is fused with NaOH in presence of air, a yellow-coloured compound (A) is obtained, which on acidification with dilute sulphuric acid gives a compound (B). Compound (B) on reaction with KCl forms an orange coloured crystalline compound (C).
(i) Write the formulae of the compounds (A), (B) and C.
(ii) Write one use of compound (C).
Complete the following equation :
`2MnO_4^(-)+6H^++5NO_2^(-)rarr`
Complete the following equations:Cr2O72- + 2OH- →
E0 value for Mn3+ Mn2+ couple is much more positive than that for Cr3-/ Cr2-.
Answer the following question.
When MnO2 is fused with KOH in the presence of KNO3 as an oxidizing agent, it gives a dark green compound (A). Compound (A) disproportionates in an acidic solution to give a purple compound (B). An alkaline solution of compound (B) oxidizes KI to compound (C) whereas an acidified solution of compound (B) oxidizes KI to (D). Identify (A), (B), (C), and (D).
Using IUPAC norms, write the formula of potassium trioxalatochromate(III).
Generally transition elements and their salts are coloured due to the presence of unpaired electrons in metal ions. Which of the following compounds are coloured?
(i) \[\ce{KMnO4}\]
(ii) \[\ce{Ce(SO4)2}\]
(iii) \[\ce{TiCl}\]
(iv) \[\ce{Cu2 Cl2}\]
The oxidation state of manganese in the product obtained in a reaction of potassium permanganate and hydrogen peroxide in a basic medium is ______.
Potassium permanganate on heating at 513 K gives a product which is ______.
Complete the reaction mentioning all the products formed:
\[\ce{Cr2O^{2-}7 + 3H2S + 8H^+ ->}\]
Indicate the steps in the preparation of \[\ce{K2Cr2O7}\] from chromite ore.
Indicate the steps in the preparation of K2Cr2O7 from chromite ore.
Indicate the steps in the preparation of \[\ce{K2Cr2O7}\] from chromite ore.
Indicate the steps in the preparation of \[\ce{K2Cr2O7}\] from chromite ore.
Indicate the steps in the preparation of \[\ce{K2Cr2O7}\] from chromite ore.
Indicate the steps in the preparation of \[\ce{K2Cr2O7}\] from chromite ore.
Indicate the steps in the preparation of \[\ce{K2Cr2O7}\] from chromite ore.
