Use Coupon: CART20 and get 20% off on all online Study Material

Total Price: R

There are no items in this cart.
Continue Shopping
Get instant 20% OFF on Online Material.
coupon code: MOB20 | View Course list

Get extra R 650 off


1.      Exactly 0.200 mole electrons is passed through two electrolytic cells in series. One contains silver ion, and the other, zinc  ion .assume that the only cathode reaction in each cell is the reduction  of the ion to the metal. How many grams of each metal will be deposited? (at. Mass of zn = 65, ag = 108)

a.       108g ag and 65 g zn.

b.      108 ag and 32.5g zn.

c.       21.6 ag and 6.5 g zn.

d.      21.6 g ag and 13 g zn.


2.       A steady current of 30.0A for 70.2 min corresponds to a passage of                                                  a.   1.2610^5  electrons.

 b.  1.26×10^5 f.

 c.  1.31 f.

 d.  1.31 c.


3.   Cu+ is not stable and undergoes disproportion. E for cu+ disproportionation.

(E°  cu2+/cu =0.153V , E°  cu+/cu=0.53V).



7 years ago


Answers : (4)



Ans 1:

For silver , the conversion is Ag+ + e- -> Ag

Therefore 1 mole of electrons are reqd to make 1 mole i.e 108 gm of silver. hence .2 moles of electron will make .2x108 = 21.6 gm of silver.


For zinc, the connversion is Zn2+ + 2e- -> Zn

Therefore 2 moles of elctrons are reqd to make 1 mole i.e 65 gm of zinc, hence .2 mole electrons shall make .2x65/2 = 6.5 gm of zinc.

7 years ago


Ans 2:

For a steady flow, the current I in amperes can be calculated with the following equation:

I = {Q \over t}


Q is the electric charge in coulombs transferred
t is the time in seconds

More generally, electric current can be represented as the time rate of change of charge, or

I = \frac{dQ}{dt}.

therefore, Q= 30 A x 70.2 x 60 sec = 126360 coulombs

1 faraday = 96 485.3415 coulombs


Therefore answer is 126360/96485.3415 = 1.31 faraday

7 years ago


Please repost the third question, the question is not clear.

7 years ago

1)       for silver deposition :       Ag+     +     e-             ------>   Ag

                                                                     1 mole                   1 mole

         so , 0.2 moles of Ag is deposited i.e., 0.2*108 = 21.6 grams


        for zinc deposition :   Zn2+     +   2e-                ------>    Zn

                                                              2 mole                       1 mole

        so , 0.1 moles of Zn is deposited i.e., 0.1*65 =  6.5 grams

        So option is C


2)   Electric current is the rate of charge flow past a given point in an electric circuit, measured in Coulombs/second which is named Amperes

     so Q = i*t


     Q = 126360 Coulombs

    but 1 faraday = 96485 Coulombs

    So its Q = 1.31 faraday

    So option is C



3) I want to make a small correction to question reg. elecric potential of  cu2+/cu+ ( taken frm standard books )

Its cu2+/cu+ =0.153V  i.e.,                     cu2+ + e-   ------>  cu           E0 = 0.153 V

Now going into problem:  Cu+ solutions, tend to give a disproportion reaction:

                                                       2Cu+ ----- >   Cu + Cu2+


                     cu+ + e-    ------>  cu                                E0 = 0.53 V        so,  nE0 = 0.53 V   

                     cu+            ------>  cu2+ + e-               E0 = - 0.153 V       so,   nE0 = - 0.153 V

on adding above rxns we get  

 2Cu+ ----- >   Cu + Cu2+                  with  E0 = +0.377 V  

7 years ago

Post Your Answer

Other Related Questions on Physical Chemistry

Please urgent. Thermochemistry question. I want to know the difference in energies and which one will be more stable and why?
Dear student The isomerised product will be more stable here due to conjugation which will lead to resonance.
Bhavya one month ago
The no. of orientation in a shell of orbit no. 5 is(a) 5 (b) 50 (c) 25 (d) 10
The number of orientation level is described my m values . So find it now by using it . But your question is no clear of what is 5 , so I have given you the concept , find it .
Drake 26 days ago
The mass ofa nonvolatile solute of malar mass 40g/mol that should be dissolved in114g of octane to lower its vapour 20% is.........
For immiscible mixtures, the relation in pre partial pressures and mole fractioon is: Pa’/Pb’ = na/nb 0.2P/P = na/(114/114) na = 0.2 moles of solute. Mass of the solute = 0.2 * 40 => 8...
2017 years ago
2) What is the relation between ionization potential and effective nuclear charge experienced by an electron in nth orbit?
effective nuclear charge experienced by an electron in nth orbit is the force of attracn. the electron experiences due to protons . And ionization potential is the potetial required to...
Vikas TU 2 months ago
The increase in effective nuclear charge results in an increase of ionisation potential or ionisation energy.
Mudit 2 months ago
how to find strenght of acids. guaranted question for boards 2017 maths phy chem
Dear student Strength of acid No of H+ ions released -I effect -R effect 1/H-bonding
Bhavya one month ago
what meant stationary and rotating polarcovalent molecule ?
@ mardana the covalent molecules which have dipole moment as 0 are called as stationary polar covalent molecules . there are also no degree of freedom of these molecules . rotating polar...
Umakant biswal 5 days ago
View all Questions »

  • Complete JEE Main/Advanced Course and Test Series
  • OFFERED PRICE: R 15,000
  • View Details
Get extra R 3,750 off

Get extra R 650 off

More Questions On Physical Chemistry

Ask Experts

Have any Question? Ask Experts

Post Question

Answer ‘n’ Earn
Attractive Gift
To Win!!!
Click Here for details