Complete and balance the following chemical equations:
(a) Fe²⁺ + MnO₄⁻ + H⁺ →
(b) MnO₄⁻ + H₂O + I⁻ →
Complete the following chemical equations :
(i) MnO₄⁻(aq) + S₂O₃²⁻(aq) + H₂O(l) →
(ii) Cr₂O₇²⁻(aq) + Fe²⁺(aq) + H⁺(aq) →
Write the preparation of following :
(i) KMnO₄ from K₂MnO₄
(ii) Na₂CrO₄ from FeCr₂O₄
(iii) Cr₂O₇²⁻ from CrO₄²⁻
Explain the following observation :
Most of the transition metal ions exhibit characteristic colour in aqueous solution.
Describe the oxidising action of potassium dichromate and write the ionic equations for its reaction with (i) an iodide (ii) H₂S.
Electronic configuration of a transition element X in +3 oxidation state is [Ar]3d⁵. What is its atomic number?
(a) 25
(b) 26
(c) 27
(d) 24
Write the formula of an oxo-anion of Chromium (Cr) in which it shows the oxidation state equal to its group number.
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.
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
(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⁻ →
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.
Consider the standard electrode potential values (M²⁺/M) of the elements of the first transition series.
Complete the following reactions—
(i) Cr₂O₇²⁻ + 6Fe²⁺ + 14H⁺ →
(ii) 2CrO₄²⁻ + 2H⁺ →
(iii) 2MnO₄⁻ + 5C₂O₄²⁻ + 16H⁺ →