Why is alternating current used for measuring resistance of an electrolytic solution?
The alternating current is used to prevent electrolysis so that the concentration of ion in the solution remains constant.
Consider a cell given below:
Cu |Cu2+ || Cl |Cl2, Pt
Write the reactions that occur at anode and cathode.
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?
Aqueous copper sulphate solution and aqueous silver nitrate solution are electrolysed by 1 ampere current for 10 minutes in separate electrolytic cells. Will the mass of copper and silver deposited on the cathode be same or different? Explain your answer.
Value of standard electrode potential for the oxidation of Cl ions is more positive than that of water, even then in the electrolysis of aqueous sodium chloride, why is Cl- oxidized at anode instead of water?
Unlike dry cell, the mercury cell has a constant cell potential throughout its useful life. Why?
Assertion (A): Copper sulphate can be stored in zinc vessel.
Reason (R): Zinc is less reactive than copper.
Arrange the following metals in the order in which they displace each other from the solution of their salts: Al, Cu, Fe, Mg and Zn.
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.
Conductivity of an electrolytic solution depends on
(b) concentration of electrolyte
(d) distance between the electrodes
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+?
Use the data given in Q. 8 and find out which of the following is the strongest oxidizing agent.
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.
Assertion (A): Mercury cell does not give steady potential.
Reason (R): In the cell reaction, ions are not involved in solution.
The conductivity of NaCl at 298 K has been determined at different concentrations and the results are given below:
A solution of Ni(N03)2 is electrolyzed between platinum electrodes using a current of 5 amperes for 20 minutes. What mass of Ni is deposited at the cathode?
A galvanic cell has electrical potential of 1.1 V. If an opposing potential of 1.1 V is applied to this cell, what will happen to the cell reaction and current flowing through the cell?
In an aqueous solution, how does specific conductivity of electrolytes change with addition of water?
Why on dilution the Am of CH3COOH increases drastically, while that of CH4COONa increases gradually?
If a current of 0.5 ampere flows through a metallic wire for 2 hours, then how many electrons would flow through the wire?
Conductivity of 0.00241 M acetic acid is 7.896 x 10-5 S cm-1. Calculate its molar conductivity. If Λm0, for acetic acid is 390.5 S cm2 mol-1, what is its dissociation constant?
E °en = 1.1 V for Daniell cell. Which of the following expressions are correct description of state of equilibrium in this cell?
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.
Assertion (A): Ecell should have a positive value for the cell to function. Reason (R). Ecadlode Eanode
Assertion (A): Conductivity of all electrolytes decreases on dilution.
Reason (R): On dilution number of ions per unit volume decreases.
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.
Assertion (A): Current stops flowing when Ecell = 0.
Reason (R): Equilibrium of the cell reaction is attained.
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?
Consultthe table of standard electrode potentials and suggest three substances that can oxidise ferrous ions under suitable conditions.
Write the chemistry of recharging the lead storage battery, highlighting all the materials that are involved during recharging.
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?
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.
For the given cell, Mg|Mg2+||Cu2+ || Cu
(a) Mg is cathode
(b) Cu is cathode
(c) The cell reaction Mg + Cu2++ — »Mg2+ + Cu
(d) Cu is the oxidizing agent
When acidulated water (dil. H2SO4 solution) is electrolysed, will the pH of the solution be affected? Justify your answer.
Assertion (A): E , increases with increase in concentration of Ag+ ions.
Ag / Ag+
Reason (R): E + has a positive value.
Ag /Ag
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?