Advertisements
Advertisements
Questions
How much electricity in terms of Faraday is required to produce 40.0 g of Al from molten Al2O3?
(Given: Molar mass of Aluminium is 27 g mol−1.)
How much electricity in terms of Faraday is required to produce 40.0 g of Al from molten Al2O3?
Advertisements
Solution
\[\ce{Al2O3 -> 2Al^{3+} + 3O^{2-}}\]
\[\ce{\underset{1 mole}{Al^3+} + \underset{3 moles}{3e-} -> \underset{1 mole}{Al}}\]
27 g of aluminium needs = 3 mole of electrons
∴ 40.0 g of aluminium needs = `(3 xx 96500 xx 40.0)/27`
= 4.28888 × 105 coulombs
= 4.44 F
RELATED QUESTIONS
On calculating the strength of current in amperes if a charge of 840C (coulomb) passes through an electrolyte in 7 minutes, it will be
- 1
- 2
- 3
- 4
The charge of how many coulomb is required to deposit 1.0 g of sodium metal (molar mass 23.0 g mol-1) from sodium ions is -
- 2098
- 96500
- 193000
- 4196
Write any four applications of electrochemical series
Number of faradays of electricity required to liberate 12 g of hydrogen is:
Using the E° values of A and B, predict which is better for coating the surface of iron [E°(Fe+2/Fe) = -0.44V] to prevent corrosion and why?
Given: E° (A+2/A)=-2.37 V: E°(B+2/B)= -0.14V
Suggest a list of metals that are extracted electrolytically.
Consider the reaction:
\[\ce{Cr2O^{2-}_7 + 14H+ + 6e- -> 2Cr^{3+} + 7H2O}\]
What is the quantity of electricity in coulombs needed to reduce 1 mol of \[\ce{Cr2O^{2-}_7}\]?
How much charge is required for the following reduction?
1 mol of Al3+ to Al.
How much charge is required for the following reduction?
1 mol of Cu2+ to Cu.
How much charge is required for the following reduction?
1 mol of \[\ce{MnO^-_4}\] to Mn2+.
A solution of Ni(NO3)2 is electrolysed between platinum electrodes using a current of 5 amperes for 20 minutes. What mass of Ni is deposited at the cathode?
Three electrolytic cells A, B, C containing solutions of ZnSO4, AgNO3 and CuSO4, respectively, are connected in series. A steady current of 1.5 amperes was passed through them until 1.45 g of silver deposited at the cathode of cell B. How long did the current flow? What mass of copper and zinc were deposited?
On passing 1.5 F charge, the number of moles of aluminium deposited at cathode are _______ [Molar mass of Al = 27 gram mol–1]
(A) 1.0
(B) 13.5
(C) 0.50
(D) 0.75
Write any two uses of H2SO4
Draw neat labelled diagram of electrolytic refining of blister copper
What is the ratio of volumes of H2 and O2 liberated during electrolysis of acidified water?
(A) 1 : 2
(B) 2 : 1
(C) 1 : 8
(D) 8 : 1
State second law of electrolysis
Calculate the mass of Ag deposited at cathode when a current of 2 amperes was passed through a solution of AgNO3 for 15 minutes.
(Given : Molar mass of Ag = 108 g mol−1 lF = 96500 C mol−1)
Write the name of the cell which is generally used in transistors. Write the reactions taking place at the anode and the cathode of this cell.
Following reactions occur at cathode during the electrolysis of aqueous copper(II) chloride solution :
On the basis of their standard reduction electrode potential (E°) values, which reaction is feasible at the cathode and why ?
How much quantity of electricity in coulomb is required to deposit 1.346 × 10-3 kg of Ag in 3.5 minutes from AgNO3 solution?
( Given: Molar mass of Ag is 108 × 10-3 kg mol-1 )
Solve the following question.
A steady current of 2 amperes was passed through two electrolytic cells X and Y connected in series containing electrolytes FeSO4 and ZnSO4 until 2.8 g of Fe deposited at the cathode of cell X. How long did the current flow? Calculate the mass of Zn deposited at the cathode of cell Y.
(Molar mass : Fe = 56 g mol–1, Zn = 65.3 g mol–1, 1F = 96500 C mol–1)
Electrolytic cell uses electrical energy to bring about ____________.
In the electrolysis of aqueous sodium chloride solution which of the half cell reaction will occur at anode?
What will happen during the electrolysis of aqueous solution of \[\ce{CuSO4}\] by using platinum electrodes?
(i) Copper will deposit at cathode.
(ii) Copper will deposit at anode.
(iii) Oxygen will be released at anode.
(iv) Copper will dissolve at anode.
What will happen during the electrolysis of aqueous solution of CuSO4 in the presence of Cu electrodes?
(i) Copper will deposit at cathode.
(ii) Copper will dissolve at anode.
(iii) Oxygen will be released at anode.
(iv) Copper will deposit at anode.
Aqueous copper sulphate solution and aqueous silver nitrate solution are electrolysed by 1 ampere current for 10 minutes in separate electrolytic cells. Will the mass of copper and silver deposited on the cathode be same or different? Explain your answer.
Time Required to deposite one millimole of aluminium metal by the passage of 9.65 ampere through aqueous solution of aluminium is
When during electrolysis of a solution of AgNO3, 9650 coulombs of charge pass through the electroplating bath, the mass of silver deposited on the cathode will be ______.
On electrolysis of dilute sulphuric acid using platinum electrodes, the product obtained at the anode will be ______.
The quantity of electricity needed to separately electrolyse 1 M solution of ZnSO4, AlCl3, and AgNO3 completely is in the ratio of ______.
Through an aqueous solution of an unknown salt of metal M (M = 200 g/mol) a current of 1.93 A is passed for 50 min. If 4 g of metal is produced at cathode. The charge on metal ion in solution is ______.
A current of 4 amp was passed for 2 hours through a solution of copper sulphate when 5.0 g of copper was deposited. The current efficiency is ______% (Cu = 63.5).
Assertion (A): During electrolysis of aqueous copper sulphate solution using copper electrodes hydrogen gas is released at the cathode.
Reason (R): The electrode potential of Cu2+/Cu is greater than that of H+/H2.
Select the most appropriate answer from the options given below:
