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]
Cd/\(Cd^{2+}\) (.10 M)//\(H_+\) (.20 M)/\(H_2\) (0.5 atm)/Pt
[Given E° for \(Cd^{2+}\) /Cd = -0.403V]
\(E_{cell}\) = \(E°_{cell}\) – 0.0591/n log [\(Cd^{2+}\)] \([\\H^+\\]^2\)
(E°_{cell}\) = 0 – (–.403V) =0.403V
=0.0403 – 0.0591/2 Log (0.10) X 0.5/(0.2)2= 0.400V
(E°_{cell}\) = 0 – (–.403V) =0.403V
=0.0403 – 0.0591/2 Log (0.10) X 0.5/(0.2)2= 0.400V
Calculate pH of following half-cell. Pt, \(H_2\) / \(H_2\)\(SO_4\) , if its electrode potential is 0.03V.
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.
State Kohlrausch law of independent migration of ions. Why does the conductivity of a solution decrease with dilution ?
The conductivity of metals decreases while that of electrolytes increases with increase in temperature. Why?
Consider the reaction: Cr₂O₇²⁻ + 14H⁺ + 6e⁻ -> 2Cr³⁺ + 7H₂O. What is the quantity of electricity in coulombs needed to reduce 1 mol of Cr₂O₇²⁻?
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.
When a certain conductance cell was filled with 0.1 M KCl, it has a resistance of 85 ohm at 25°C. When the same cell was filled with an aqueous solution of 0.052 M unknown electrolyte, the resistance was 96 ohms. Calculate the molar conductance of the electrolyte at this concentration.
[Specific conductance of 0.1 M KCl = 1.29 × 10⁻² ohm⁻¹ cm⁻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.
Consider the standard electrode potential values (M²⁺/M) of the elements of the first transition series.
(i) Give reasons for the following :
(a) Compounds of transition elements are generally coloured.
(b) MnO is basic while Mn₂O₇ is acidic.
(ii) Calculate the magnetic moment of a divalent ion in aqueous medium if its atomic number is 26.
The vapour pressure of pure liquids A and B at 400 K are 450 and 700 mm Hg respectively. Find out the composition of liquid mixture if total pressure at this temperature is 600 mm Hg.