Account for the following :
(i) CuCl₂ is more stable than Cu₂Cl₂.
(ii) Atomic radii of 4d and 5d series elements are nearly same.
(iii) Hydrochloric acid is not used in permanganate titration.
(i) CuCl₂ is more stable than Cu₂Cl₂.
(ii) Atomic radii of 4d and 5d series elements are nearly same.
(iii) Hydrochloric acid is not used in permanganate titration.
(i) In CuCl₂, Cu is in +2 oxidation state which is more stable due to high hydration enthalpy as compared to Cu₂Cl₂ in which Cu is in +1 oxidation state.
(ii) Due to lanthanoid contraction.
(ii) Because HCl is oxidised to chlorine.
(ii) Due to lanthanoid contraction.
(ii) Because HCl is oxidised to chlorine.
Explain the following observation :
Most of the transition metal ions exhibit characteristic colour in aqueous solution.
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.
(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⁻ →
How would you account for the following ? Many of the transition elements are known to form interstitial compounds.
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.
Describe the preparation of potassium permanganate. How does the acidified permanganate solution react with oxalic acid ?
Write the ionic equations for the reactions.
When Cu²⁺ ion is treated with KI, a white precipitate is formed. Explain the reaction with the help of chemical equation.
(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 \(mol^{–1}\)
The molar conductivity of 0.025 mol L⁻¹ methanoic acid is 46.1 S cm² mol⁻¹. Calculate its degree of dissociation and dissociation constant. Given λ°(H⁺) = 349.6 S cm² mol⁻¹ and λ°(HCOO⁻) = 54.6 S cm² mol⁻¹.
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.
Calculate the molar conductivity and degree of dissociation.
Conductivity of 2.5 × 10⁻⁴M methanoic acid is 5.25 × 10⁻⁵ Scm⁻¹.
Given : = 50.5Scm² mol⁻¹
(i) Complete the following equations :
(a) 2MnO₄⁻ + 5SO₃²⁻ + 6H⁺ →
(b) Cr₂O₇²⁻ + 6Fe²⁺ + 14H⁺ →
(ii) Based on the data, arrange Fe²⁺, Mn²⁺ and Cr²⁺ in the increasing order of stability of +2 oxidation state.
E°(Cr³⁺/Cr²⁺) = -0.4 V
E°(Mn³⁺/Mn²⁺) = +1.5 V
E°(Fe³⁺/Fe²⁺) = + 0.8 V
Account for the following :
(i) CuCl₂ is more stable than Cu₂Cl₂.
(ii) Atomic radii of 4d and 5d series elements are nearly same.
(iii) Hydrochloric acid is not used in permanganate titration.
Calculate emf of the following cell
Cd/\(Cd^{2+}\) (.10 M)//\(H_+\) (.20 M)/\(H_2\) (0.5 atm)/Pt
[Given E° for \(Cd^{2+}\) /Cd = -0.403V]