Q. 17 B5.0( 4 Votes )
Transition metals show variable oxidation states.
Transition metals show variable oxidation states because of the participations of ns and (n-1)d electrons in bonding. Lower oxidation state os exhibited when the ns electrons take part in bonding. Higher oxidation states are exhibited when the (n-1)d electrons take part in bonding.
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Transition metals show variable oxidation states.Chemistry - Board Papers
Write the formula of an oxo-anion of Manganese (Mn) in which it shows the oxidation state equal to its group number.Chemistry - Board Papers
Mention the type of compounds formed when small atoms like H, C and N gettrapped inside the crystal lattice of transition metals. Also give physical and chemical characteristics of these compounds.Chemistry - Exemplar
(a) Answer the following questions :
(i) Which element of the first transition series has highest second ionization enthalpy?
(ii) Which element of the first transition series has highest third ionization enthalpy?
(iii) Which element of the first transition series has lowest enthalpy of atomisation?
(b) Identify the metal and justify your answer.
(i) Carbonyl M (CO)5
Chemistry - Exemplar
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 solution, orange crystals of compound (D) crystallise out. Identify compounds A to D and also explain the reactions.
An oxide of mangnese (A) is fused with KOH in the presence of an oxidizing agent and dissolved in water. A dark green solution of compound (B) is obtained. Compound (B) disproportionates in neutral or acidic solution to give purple compound (C). Alkaline solution of (C) oxidises potassium iodide solution to a compound (D) and compound (A) is also formed. Identify compounds A to D and also explain the reactions involved.
Chemistry - Exemplar