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Showing posts with label ELECTROCHEMISTRY. Show all posts
Showing posts with label ELECTROCHEMISTRY. Show all posts

Friday, May 14, 2021

How many gram Cu will deposited by passing 2 Amp for 30 minutes in aq solution of CuSO4. What will be weight of O2 produced at anode?


Related Questions:

(1) A current of 2.68 ampere is passed for one hour through an aqueous solution of copper sulphate using copper electrodes. Calculate the change in the mass cathode and that of anode. ( atomic mass of copper is 63.5 u).

(3) On passing 3 faradays of electricity through three electrolytic cells connect in series containing Ag+ , Ca+2 and Al+3 ions respectively , the molar ratio in which three metals ions are liberated at the electrode is





Tuesday, May 11, 2021

Find the Volume of gas evolved by passing 0.965 Amp current for 1 hour through an aqueous solution CH3COONa at 250c and 1 atm?


Related Questions:

(1) A current of 2.68 ampere is passed for one hour through an aqueous solution of copper sulphate using copper electrodes. Calculate the change in the mass cathode and that of anode. ( atomic mass of copper is 63.5 u).

(3) On passing 3 faradays of electricity through three electrolytic cells connect in series containing Ag+ , Ca+2 and Al+3 ions respectively , the molar ratio in which three metals ions are liberated at the electrode is

During electro refining of Cu how much time is needed to produce 250g Cu on the cathode if the current is kept at 11 A?

Given that current (i) = 11 A = 11 cycle/second

Number of moles of copper deposited on cathode is 


Related Questions:

(1) A current of 2.68 ampere is passed for one hour through an aqueous solution of copper sulphate using copper electrodes. Calculate the change in the mass cathode and that of anode. ( atomic mass of copper is 63.5 u).

(3) On passing 3 faradays of electricity through three electrolytic cells connect in series containing Ag+ , Ca+2 and Al+3 ions respectively , the molar ratio in which three metals ions are liberated at the electrode is

Zn amalgam is prepared by electrolysis of aqueous ZnCl2 using 9 gram Hg cathode. How much current is to be passed through ZnCl2 solution for 1000 seconds to prepare of Zn amalgam with 20% weight? (Atomic wt, Zn = 65.4 g)

 Let “x “gram of Zn deposited on 9 gm of Hg:


Related Questions:

(1) A current of 2.68 ampere is passed for one hour through an aqueous solution of copper sulphate using copper electrodes. Calculate the change in the mass cathode and that of anode. ( atomic mass of copper is 63.5 u).

(3) On passing 3 faradays of electricity through three electrolytic cells connect in series containing Ag+ , Ca+2 and Al+3 ions respectively , the molar ratio in which three metals ions are liberated at the electrode is



Monday, May 10, 2021

1 M aqueous solution of NaCl undergo electrolysis if 50 mA current is passed for 12 hours assume current efficiency is 25%. The total volume of gas produced at standard state is. NaCl (aq) solution undergoes electrolysis as:

NaCl(aq) àNa+ + Cl-

        H2O à H+ + HO-

Reactions:

At cathode: 2H+ + 2e-à H2(g)

At anode:   2Cl-à Cl2(g) + 2e-


Related Questions:

(1) A current of 2.68 ampere is passed for one hour through an aqueous solution of copper sulphate using copper electrodes. Calculate the change in the mass cathode and that of anode. ( atomic mass of copper is 63.5 u).


How long has a current of 3 ampere to be applied through a solution of silver nitrate to coat a metal surface of 80 cm2 with 0.005 cm thick layer density of silver is 10.5g/cm3.

Given Area = 80 cm3

   Thickness = 0.0005 cm

        Density= 10.5 gl cm3

Thus Mass of silver deposited on cathode is = 80 cm3 x 0.0005 cm x10.5 gm/cm3= 0.42 gm

Related Questions:


0.5 faraday of electricity was passed to deposit all the copper present in 500 ml of CuSO4 solution. What was the Molarity of this solution?

 

Related Questions:

(1) A current of 2.68 ampere is passed for one hour through an aqueous solution of copper sulphate using copper electrodes. Calculate the change in the mass cathode and that of anode. ( atomic mass of copper is 63.5 u).

Ag is electrodeposited on a vessel of total surface area 800 cm2 by passing current of 0.2 A for 3 hrs. Calculate thickness of Ag deposited. (Density Ag = 9.67 g/ml).

 


(1) A current of 2.68 ampere is passed for one hour through an aqueous solution of copper sulphate using copper electrodes. Calculate the change in the mass cathode and that of anode. ( atomic mass of copper is 63.5 u).

Sunday, May 9, 2021

A current of 2.68 ampere is passed for one hour through an aqueous solution of copper sulphate using copper electrodes. Calculate the change in the mass cathode and that of anode. ( atomic mass of copper is 63.5 u).


Related Questions:

(1) The conductivity of 0.0011028 mol per liter acetic acid is 4.95 × 10–5 S per cm. Calculate its dissociation constant if ^°m for acetic acid is 390.5 S cm2 per mol–1 .


What current strength ampere will be require to liberate 10 gm chlorine from sodium chloride solution in one hour?

 

Related Questions:

(1) The conductivity of 0.0011028 mol per liter acetic acid is 4.95 × 10–5 S per cm. Calculate its dissociation constant if ^°m for acetic acid is 390.5 S cm2 per mol–1 .

Friday, May 7, 2021

The standard reduction potential for Cu2+/Cu is +0.3.4 volt calculate the reduction potential at PH =14 for above couple. ksp fo Cu(OH)2 is 1.0x10^-19.

Metal-Metal- Insoluble salts electrode:

These consist of a metal (M) which is covered by a layer of sparingly soluble salt (MX), immersed in solution containing common ions (X-). And it is represented as anode or anion electrode.

M I MX (sat’d) I X-  for example  Ag I AgCl (sat’d) I Cl-  II  Cathode

We Know that AgX (F, Cl, Br,I) Silver salt’s are insoluble in water.

Other examples:

(1) Hg(s) I Hg2SO4(sat’d) I SO4-2 II    (Cathode)  used in the standard Weston Cell.

(2) Hg(s) I Hg2Cl2(sat’d) I Cl- (KCl paste) II    (Cathode) used as Calomel electrode

(3) Pb(s) I PbSO4(sat’d) I SO4-2 II    (Cathode)  used in lead batteries

(4) Cu(s) I CuCl2(sat’d) I Cl- (KCl paste) II    (Cathode)

(1) Silver electrode as Anode or anionic electrode:

Ag I AgCl (sat’d) I Cl-  II  Cathode

The electrode reaction can be considered as taking place in two steps as.

This electrode reaction involve only the concentration of chloride ion, the electrode is said to be reversible with respect to chloride ions (Cl-).

The above reaction show how an electron can be released or taken up in such electrode.

Nernst equation for this electrode (Anode) is written as:

Silver electrode as cathode or cationic electrode:

   Anode   II Cl- aq I AgCl(sat’d)IAg(s)

Nernst equation for this electrode (Cathode) is written as:

(2) Calomel electrode:

A calomel cell consist of a platinum electrode dipping into mercury in contact with calomel (dimercury (I) chloride,Hg2Cl2 and potassium chloride solution.

As Anode:

Hg(s) I Hg2Cl2(sat’d) I Cl- (KCl paste) II    (Cathode) :

As Cathode:

  Anode          II Cl- (KCl paste)I Hg2Cl2(sat’d) I Hg(s)    

Related Questions:

(1) The conductivity of 0.0011028 mol per liter acetic acid is 4.95 × 10–5 S per cm. Calculate its dissociation constant if ^°m for acetic acid is 390.5 S cm2 per mol–1 .