Q21 of 30 Page 1

Calculate the emf of the following cell at 298 K:

Fe(s) | Fe2+ (0.001M)|| H+(1M) | H2(g) (1bar), Pt(s)


(Given E°cell = +0.44V)


At anode: [Oxidation]


At cathode: [Reduction]


Total electrons transferred (n) = 2.


Also, E°cell = +0.44V


From Nernst equation, we know,


Ecell = E0cell – () [Coxid = concentration at the oxidation cell (0.001 M) and Cred = concentration at the reduction cell(1M)]


= 0.44 – ()


= 0.44 – (0.0295× -3)


= 0.44 + 0.08865 = 0.53V


More from this chapter

All 30 →
19

(a) What type of semiconductor is obtained when silicon is doped with boron?

(b) What type of magnetism is shown in the following alignment of magnetic moments?



(c) What type of point defect is produced when AgCl is doped with CdCl2?


 20

Determine the osmotic pressure of a solution prepared by dissolving 2.5 × 10–2 g of K2SO4 in 2L of water at 25°C, assuming that it is completely dissociated.

(R =0.0821 L atm K–1mol–1, Molar mass of K2SO4= 174gmol-1)


 22

How would you account for the following?

(i) Transition metals exhibit variable oxidation states.


(ii) Zr (Z = 40) and Hf (Z = 72) have almost identical radii.


(iii) Transition metals and their compounds act as catalyst.


OR


Complete the following chemical equations:


(i)


(ii)


(iii)


23

Write the IUPAC names of the following coordination compounds:

(i) [Cr(NH3)3Cl3]


(ii) K3[Fe(CN)6]


(iii)[CoBr2(en)2]+, (en=ethylenediamine)