Given the standard electrode potentials, K+/K=-2. 93 V, Ag+/Ag = 0.80 V, Hg2+/Hg =0.79V, Mg2+/Mg=-2.37V, Cr3+/Cr=0.74V.
Arrange these metals in their increasing order of reducing power.
Higher the oxidation potential more easily it is oxidized and hence greater is the reducing power. Thus, increasing order of reducing power will be Ag
The conductivity of 0.20 M solution of KCl at 298 K is 0.0248 S cm-1. Calculate its molar conductivity.
E °en = 1.1 V for Daniell cell. Which of the following expressions are correct description of state of equilibrium in this cell?
The positive value of the standard electrode potential of Cu+2/Cu indicates that
(a) this redox couple is a stronger reduction agent than the H/H2 couple
(b) this redox couple is a stronger oxidizing agent than H+/H2
(c) Cu can displace H2 from acid
(d) Cu cannot displace H2 from acid
Assertion (A): E , increases with increase in concentration of Ag+ ions.
Ag / Ag+
Reason (R): E + has a positive value.
Ag /Ag
Calculate the potential of hydrogen electrode in contact with a solution whose pH is 10.
How much charge is required for the following reductions:
(i) 1 mol of Al3+ to Al?
(ii) 1 mol of Cu2+ to Cu ?
(iii) 1 mol of Mn04- to Mn2+?
Three electrolytic cells A, B, C containing solutions of ZnS04, AgNO3 and CuS04, respectively are connected in series. A steady current of 1.5 amperes was passed through them until 45 g of silver deposited at the cathode of call B. How long did the current flow? What mass of copper and zinc were deposited?
What will happen during the electrolysis of aqueous solution of CuSO4 in the presence of Cu electrodes?
(a) Copper will deposit at cathode.
(b) Copper will dissolve at anode.
(c) Oxygen will be released at anode.
(d) Copper will deposit at anode.
Define conductivity and molar conductivity for the solution of an electrolyte. Discuss their variation with concentration.
Consultthe table of standard electrode potentials and suggest three substances that can oxidise ferrous ions under suitable conditions.
The cell in which the following reaction occurs: 2Fe3+ (aq) + 2I– (aq) —> 2Fe2+ (aq) +I2 (s) has E °cell=0.236 V at 298 K. Calculate the standard Gibbs energy and the equilibrium constant of the cell reaction.
In the button cells widely used in watches and other devices the following reaction takes place:
Write the Nemst equation for the cell reaction in the Daniell cell. How will the Ecell be affected when concentration of Zn2+ ions is increased?
Consider the figure given below and answer the questions (i) to (vi) that follow.
(i) Redraw the diagram to show the direction of electron flow.
(ii) Is silver plate anode or cathode?
(iii)What will happen if salt bridge is removed?
(iv)When will the cell stop functioning?
(v)How will concentration of Zn+2 cell functions?
(vi)How will the concentration of Zn+2 ions and Ag+ ions be affected after the cell becomes ‘dead'?
Which reference electrode is used to measure the electrode potential of other electrodes?
Calculate the emf of the cell in which the following reaction takes place:
Ni(s)+2Ag+ (0.002 M) -> Ni2+ (0.160 M)+2Ag(s) Given that E(-)(cell) = 1.05 V .
In the electrolysis of aqueous sodium chloride solution, which of the half-cell reaction will occur at anode?
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 Al203?
Use the data given in Q. 8 and find out which of the following is the strongest oxidizing agent.
The quantity of charge required to obtain one mole of aluminium from
Al2O3 is (a) IF (b) 6F (c) 3F (d) 2F
In an aqueous solution, how does specific conductivity of electrolytes change with addition of water?
Given the standard electrode potentials, K+/K=-2. 93 V, Ag+/Ag = 0.80 V, Hg2+/Hg =0.79V, Mg2+/Mg=-2.37V, Cr3+/Cr=0.74V.
Arrange these metals in their increasing order of reducing power.
Assertion (A): For measuring resistance of an ionic solution an AC source is used.
Reason (R): Concentration of ionic solution will change if DC source is used.
Solutions of two electrolytes 'A' and 'B' are diluted. The Am of 'B' increases 1.5 times while that of A increases 25 times. Which of the two is a strong electrolyte? Justify your answer.
Why on dilution the Am of CH3COOH increases drastically, while that of CH4COONa increases gradually?
What is the relationship between Gibbs free energy of the cell reaction in a galvanic cell and the emf of the cell? When will the maximum work be obtained from a galvanic cell?
Predict the products of electrolysis in each of the following.
(i) An aqueous solution of AgNO3 with silver electrodes.
(ii) An aqueous solution of AgNO3 with platinum electrodes.
(iii) A dilute solution of H2S04 with platinum electrodes.
(iv) An aqueous solution of CuCl2 with platinum electrodes.
What will happen during the electrolysis of aqueous solution of CuSO4 by using platinum electrodes?
(a) Copper will deposit at cathode.
(b) Copper will deposit at anode.
(c) Oxygen will be released at anode.
(d) Copper will dissolve at anode.
When acidulated water (dil. H2SO4 solution) is electrolysed, will the pH of the solution be affected? Justify your answer.
Write the cell reaction of a lead storage battery when it is discharged. How does the density of the electrolyte change when the battery is discharged?
Assertion (A): Electrolysis of NaCl solution gives chlorine at anode instead of 02.
Reason (R): Formation of oxygen at anode requires overvoltage.
Assertion (A): Copper sulphate can be stored in zinc vessel.
Reason (R): Zinc is less reactive than copper.
Consider the following figure and answer the following questions.
(i) Cell ‘A' has Ecell = 2 V and cell ‘B' has Ecen = 1.1 V which of the two cells ‘A' or ‘B' will act as an electrolytic cell. Which electrode reactions will occur in this cell?
(ii) If cell ‘A' has Ecen = 0.5 V and cell ‘B' has Ecen = 1.1 V, what will be the reactions at anode and cathode?
If a current of 0.5 ampere flows through a metallic wire for 2 hours, then how many electrons would flow through the wire?
