Metallic radii of some transition elements are given below. Which of these elements will have highest density?
Suggest reasons for the following features of transition metal chemistry :
(i) The transition metals and their compounds are usually paramagnetic.
(ii) The transition metals exhibit variable oxidation states.
Explain the following observation :
Most of the transition metal ions exhibit characteristic colour in aqueous solution.
The magnetic moment is associated with its spin angular momentum and orbital angular momentum. Spin only magnetic moment value of Cr³⁺ ion is
(a) 2.87 BM
(b) 3.87 BM
(c) 3.47 BM
(d) 3.57 BM
Describe the oxidising action of potassium dichromate and write the ionic equations for its reaction with (i) an iodide (ii) H₂S.
Explain the following :
(i) The enthalpies of atomization of transition metals are quite high.
(ii) The transition metals and many of their compounds act as good catalysts.
Describe the preparation of potassium permanganate. How does the acidified permanganate solution react with oxalic acid ?
Write the ionic equations for the reactions.
Consider the reaction: Cr₂O₇²⁻ + 14H⁺ + 6e⁻ -> 2Cr³⁺ + 7H₂O. What is the quantity of electricity in coulombs needed to reduce 1 mol of Cr₂O₇²⁻?
The electrical resistance of a column of 0.05 M KOH solution of diameter 1 cm and length 45.5 cm is 4.55 × 10³ ohm. Calculate its molar conductivity.
(a) Calculate G° for the reaction
Zn(s) + \(Cu^{2+}\)(aq) → \(Zn^{2+}\)(aq) + Cu(s)
Given: E° for \(Zn^{2+}\)/Zn = -0.76V and E° for \(Cu^{2+}\)/Cu = +0.34 V
R = 8.314 \(JK^{–1}\) \(mol^{–1}\), F = 96500 \(mol^{–1}\)
Out of the following pairs, predict with reason which pair will allow greater conduction of electricity:
(i) Silver wire at 30°C or silver wire at 60°C.
(ii) 0.1 M \(CH_3\)COOH solution or 1 M \(CH_3\)COOH solution.
(iii) KCl solution at 20°C or KCl solution at 50°C.
Consider the standard electrode potential values (M²⁺/M) of the elements of the first transition series.
Give reasons :
(i) Mn shows the highest oxidation state of +7 with oxygen but with fluorine it shows the highest oxidation state of +4.
(ii) Transition metals show variable oxidation states.
(iii) Actinoids show irregularities in their electronic configurations.
(i) Account for the following :
(a) Cu⁺ is unstable in an aqueous solution.
(b) Transition metals form complex compounds.
(ii) Complete the following equation :
CrO₂₇²⁻ + 8H⁺ + 3NO₂⁻ →