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Class 10 Class 12
The molar conductivity of KCl solutions at different concentration at 298 K are given below:
 C/mol L–1 Λ/s cm2 mol–1 0.000198 0.000309 0.000521 0.000989 148.61 148.29 147.81 147.09
Show that a plot between A and C1/2 is a straight line. Determine the values of Λ° and Λ for KCl.

Taking the square root of concentration, we have
 C1/2 /(mol L–1)1/2 A/s cm2 mol–1 0.01407 0.01758 0.02283 0.03145 148.61 148.29 147.81 147.09

A plot of A(l /-axis) and c1/2 (x-axis) is shown in the fig. It is nearly a straight line. From the intercept (C1/2 = 0) we find that Λ° = 149.8 s cm2 mol–1 and Slope = A = 87.46s cmmol–1/(mol / L–1)1/2.

355 Views

How would you determine the standard electrode potential of the system Mg2+/Mg?

Use standard hydrogen electrode as anode and Mg2+ | Mg as a cathode we can measure the standard electrodepotential of systemMg2+ | Mg. Standard hydrogen electrode, represented by Pt(s), H2(g) (1 atm) | H+ (aq) and dip the electrode of Magnesium wire in a 1M MgSO4 solution .The standard hydrogen electrode is always zero.
Use formula
Eocell = Eo right  – Eoleft
The standard hydrogen electrode is always zero.
So that the value of
Eoleft =0
Hence
Eocell = Eo Mg|Mg2+
Or
Eo Mg|Mg2+= Eocell
2203 Views

Can you store copper sulphate solutions in a Zinc pot?

No. Because zinc is more reactive than copper and thus holes will be developed in zinc pot.

Cu2+(aq) + Zn(s) → Zn2+ (aq) + Cu(s)
1384 Views

Calculate the emf of the cell in which the following reaction takes place:
Ni(s) + 2Ag+ (0.002 M) $\to$ Ni2+ (0.160 M) + 2Ag(s)
Given that

$\mathrm{Ni}\left(\mathrm{s}\right)+2{\mathrm{Ag}}^{+}\left(\mathrm{aq}\right)\to {\mathrm{Ni}}^{2+}\left(\mathrm{aq}\right)+2\mathrm{As}\left(\mathrm{s}\right)$

or

The equation is also written as

or

= 1.05 V – 0.0295 x log 80

= 1.05 V – 0.0295 x 1.9031

= 1.05 V – 0.056 = 0.99 V.

1585 Views

Consult the table of standard electrode potentials and suggest three substance that can oxidize ferrous ions under suitable conditions.

oxidation of ferrous ion means :

Fe2+--> Fe3+ +e-
Any substance which standard electrode potential is more than that of Fe+3 /F+2 can oxidise ferrous ions.
(refer to the table given in book)

The EMF of the substance whose reduction potentials greater than 0.77V will oxidised ferrous ion.
for example Br2, Cl2,and F2 .

879 Views

Calculate the potential of hydrogen electrode in contact with a solution whose pH is 10.