20 Questions Available
Showing 20 questions on this page
Predict if the reaction between the following is feasible :
(i) Fe3+ (aq) and I–(aq)
(ii) Ag + (aq) and Cu
(iii) Fe3+ and Br–(aq)
(iv) Ag (s) and Fe3+ (aq)
(v) Br2 (aq) and Fe2+ (aq)
Given standard electrode potentials : Eº1/2/I– = 0.541, Eº Cu2+/ Cu = 0.34 V, Eº 1/2 Br2/Br– = 1.09 V, EºAg+/ Ag = +0.80 V, EºFe3+/ Fe2+ = +0.77 V
A solution of Ni(NO3)2 is electrolysed between platinum electrodes using a current of 5.0 ampere for 20 minutes. What mass of nickel will be deposited at the cathode ? (At. mass of Ni = 58.7)
Can you store copper sulphate solution in a zinc pot?
Predict the products of electrolysis of the following :
(i) An aqueous solution of AgNO3 with silver electrodes
(ii) An aqueous solution of AgNO3 with platinun electrodes
(iii) A dilute acqueous solution of H2SO4 with platinum electrodes
(iv) An aqueous solution of CuCI2 with platinum electrodes.
(Given E°Ag+/Ag = +0.80 V, E°Cu2+/Cu = +0.34 V)
Calculate the standard cell potentials of galvanic cells in which the following reactons take place :
(i) 2 Cr (s) + 3 Cd2+ (aq) → 2Cr3+ (aq) + 3 Cd(s)
(ii) Fe2+ (aq) + Ag+ (aq) → Fe3+ (aq) + Ag(s)
Given EºCr3+, Cr = –0.74 V, EºCd2+/ Cd = 0.40 V, EºAg+/Ag = 0.80 V, Eº Fe3+/ Fe2+ = 0.77 V
Also calculate ∆rGº and equilibrium constants of the reactions.
How much electricity in terms of Faraday is required to produce?
(i) 20.0 g of Ca from molten CaCl2
(ii) 40.0 g of Al from molten Al2O3?
Depict the galvanic cell in which the reaction Zn(s) + 2 Ag+ (aq) → Zn2+ (aq) + 2Ag(s) takes place. Further, show
(i) Which of the electrodes is negatively charged ?
(ii) the carriers of the current in the cell.
(iii) Individual reaction at each electrode.
Write the chemistry of recharging the lead storage battery, highlighting all the materials that are involved during recharging.
Three electrolytic cells A, B and C containing electrolytes ZnSO4, AgNO3 and CuSO4 respectively were connected in series. A steady current of 1.50 ampere was passed through them until 1.45 g of Ag were deposited at the cathode of cell B. How long did the current flow? What mass of copper and zinc were deposited ? (At. wts. of Cu = 63.5, Zn = 65.3, Ag = 108)
Write the Nernst equation and calculate the e.m.f. of the following cells at 298 K.
(i) Mg (s) | Mg2+ (0.001 M) | | Cu2+ (0.001 M) | Cu (s)
(ii) Fe (s) | Fe2+ (0.001 M) | | H+ (1 M) | H2 (g) (1 bar) | Pt (s)
(iii) Sn (s) | Sn2+ (0.050 M) | | H+ (0.020 M) | H2 (g) (1 bar) | Pt (s)
(iv) Pt (s) | Br2 (l) | Br– (0.010 M) | | H+ (0.030 M) | H2 (g) (1 bar) | Pt (s)
Given EºMg2+/Mg = 2.37 V, EºCu2+/Cu = +0.34 V, EºFe2+ Fe = – 0.44 V, EºSn2+/Sn = – 0.14 V, Eº1/2 Br2/ Br– = + 1.08 V.
In the button cell widely used in watches and other devices, the following reaction takes place :
Zn(s) + Ag2O(s) + H2O (l) → Zn2+ (aq) + 2 Ag(s) + OH– (aq)
Determine Eº and DrGº for the reaction.
Zn → Zn2+ + 2e–, Eº = 0.76 V ; Ag2O + H2O + 2 e– → 2 Ag + 2 OH–, Eº = 0.344V.
Conductivity of 0.00241 M acetic acid is 7.896 × 10–5 S cm–1. Calculate its molar conductivity and if ∧° for acetic acid is 390.5S cm2 mol–1, what is its dissociation constant?
The cell in which the following reaction occurs :
2Fe3+ (aq) + 2I– (aq) → 2Fe2+ (aq) + I2(s)
has Eºcell = 0.236 V at 298 K. Calculate the standard Gibbs energy and the equilibrium constant of the cell reaction.
Calculate the potential of hydrogen electrode in contact with a solution whose pH is 10.
Explain how rusting of iron is envisaged as setting up of an electrochemical cell.
Suggest a way to determine the ∧° m value of water.
Calculate the emf of the cell in which the following reaction takes place :
Ni(s) + 2 Ag+ (0.002 M) → Ni2+ (0.160 M) + 2 Ag (s) Given that Eºcell = 1.05 V
Why does the conductivity of a solution decrease with dilution ?
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 λº (H+) = 349.6 S cm2 mol–1 and λº (HCOO–) = 54.6 S cm2 mol–1.
Arrange these metals in their increasing order of reducing power.
