Selective Discharge of Ions

IMPORTANT

Selective Discharge of Ions: Overview

In this topic, we will learn about the selective discharge of ions in the process of electrolysis. We will also discuss the electrochemical series, which contains the metals in the order of their tendency to lose valence electron.

Important Questions on Selective Discharge of Ions

MEDIUM
IMPORTANT

Given that the standard electrode potentials  (E°) of metals are:

 K+/K=2.93V,Ag+/Ag=0.80V,Cu2+/Cu=0.34V,

 Mg2+/Mg=2.37V,Cr3+/Cr=0.74V,Fe2+/Fe=0.44V.

The increasing order of their reducing power is:

EASY
IMPORTANT

Of the halide ions, the most powerful reducing agent is:

MEDIUM
IMPORTANT

The standard reduction potential values of three metallic cations, X, Y and Z are 0.52,3.03 and1.18V respectively. The order of reducing power of the corresponding metals is:

MEDIUM
IMPORTANT

Standard electrode potential of three metals A, B and C are   + 0.5 V, 3.0 V and 1.2 V respectively. The reducing power of these metals are

EASY
IMPORTANT

H2 cannot be displaced by

HARD
IMPORTANT

The standard electrode potential of M2+/M is positive for

EASY
IMPORTANT

Lower the position of an ion in an electrochemical series more easily it will get discharged at the respective electrode.

EASY
IMPORTANT

How does nature of electrode affect selective discharge of ions.

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If a solution contains more than two cations and anions, the selective discharge of ions depends on electrochemical series.

EASY
IMPORTANT

Define selective discharge of ions.

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Identify the easily oxidisable halide.

EASY
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Select the correct option, for the given standard Eo values of few redox couples:
Zn2+/Zn=-0.76V, Ag+/Ag=+0.80V, Cu2+/Cu=0.34V
 

EASY
IMPORTANT

Mark the correct statement based on the Eo values of redox couple of halogens given below
 EoI2/I-=+0.54V,EoBr2/Br-=+1.08V;EoCl2/Cl-=+1.36V.

MEDIUM
IMPORTANT

One metal X displaces nickel from nickel sulphate solution but does not displace manganese from manganese sulphate solution. The correct order of their reducing powers is:

MEDIUM
IMPORTANT

Which element can reduce Aluminium?

HARD
IMPORTANT

Match the column :

 

  Column I   Column II
A) Molten PbCl2 using inert electrodes p) Metal of salt reduced.
B)

Sodium chloride solution

using inert electrodes

q) H2O+2eH2(g)+2OH
C) Silver nitrate solution with silver electrodes r) Solution becomes basic after electrolysis.
D) Sodium nitrate solution using inert electrodes s) Solution becomes neutral after electrolysis.
    t) Solution becomes acidic after electrolysis.

EASY
IMPORTANT

Out of which of the following statements is true- 

Given the reduction potential data as-  EAg+/Ago=+0.8 V, ENi+2/Nio=- 0.25 V  .

MEDIUM
IMPORTANT

Select the correct statements based on standard electrode potential of some half cell reactions are given below:
(A)    Sn+4+2e-Sn2+, E°=+0.15V
(B)    2Hg+2+2e-Hg2+2, E°=+0.92V
(C)    PbO2+4H++2e-Pb+2+2H2O, E°=+1.45V

EASY
IMPORTANT

Among the following, which is the most reactive metal which displaces other metals from their salts in solution?

EZn/Zn2+0=+0.76V, EAg/Ag+0=-0.80V, 

ECu/Cu2+0=-0.34V, ECo/Co+20=0.28V

EASY
IMPORTANT

We have taken two electrode, with potential values: EMg2+/Mga=- 2.37 V and EbFe3+/Fe =-0.04 V. Which of the following will act as the best reducing agent: