Calculate pH of following half-cell. Pt, \(H_2\) / \(H_2\)\(SO_4\) , if its electrode potential is 0.03V.
pH = - log [H^+]
½ \(H^+\) e- → \(H_2\) (g)
\(E_{cell}\) = \(E°_{cell}\) - 0.059/n log 1/[\(H^+\)]
0.03 = 0- 0.059 /1 log 1/[\(H^+\)]
pH = 5.07 V
½ \(H^+\) e- → \(H_2\) (g)
\(E_{cell}\) = \(E°_{cell}\) - 0.059/n log 1/[\(H^+\)]
0.03 = 0- 0.059 /1 log 1/[\(H^+\)]
pH = 5.07 V
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]
The potential of a hydrogen electrode at pH = 10 is
a. 0.591 V
b. 0.00 V
c. – 0.591 V
d. -0.059 V
The conductivity of 0.20 M solution of KCl at 298 K is 0.025 Scm⁻¹. Calculate its molar conductivity.
The conductivity of metals decreases while that of electrolytes increases with increase in temperature. Why?
State Kohlrausch law of independent migration of ions. Why does the conductivity of a solution decrease with dilution ?
What is meant by ‘disproportionation’ ? Give an example of a disproportionation reaction in aqueous solution.
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 a orange coloured crystalline compound (C).
(i) Write the formulae of the compounds (A), (B) and (C).
(ii) Write one use of compound (C).
Define the following terms :
(i) Fuel cell
(ii) Limiting molar conductivity
Calculate pH of following half-cell. Pt, \(H_2\) / \(H_2\)\(SO_4\) , if its electrode potential is 0.03V.
Explain why :
(i) E° for Mn³⁺/Mn²⁺ couple is more positive than that for Fe³⁺/Fe²⁺. (At. Nos. Mn = 25, Fe = 26).
(ii) Ce³⁺ can be easily oxidized to Ce⁴⁺. (At. No.Ce = 58).
Name the following :
(i) A transition metal which does not exhibit variation in oxidation state in its compounds.
(ii) A compound where the transition metal is in the +7 oxidation state.
(iii) A member of the lanthanoid series which is well known to exhibit +4 oxidation state.
(iv) Ore used in the preparation of Potassium dichromate.
In the following ions:
Mn³⁺, V³⁺, Cr³⁺, Ti⁴⁺
(Atomic no: Mn = 25, V = 23, Cr = 24, Ti = 22)
(a) Which ion is most stable in an aqueous solution?
(b) Which ion is the strongest oxidizing agent?
(c) Which ion is colourless?
(d) Which ion has the highest number of unpaired electrons?