Advertisements
Advertisements
प्रश्न
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?
Advertisements
उत्तर १
\[\ce{Ag^+ + e^- -> Ag}\]
108 g Ag is deposited = 1 F = 96500 C
∴ 1.45 g Ag will be deposited = \[\ce{\frac{96500}{108} \times 1.45}\]
= 1295.6 C
Q = I × t
⇒ t = \[\ce{\frac{Q}{I}}\]
= \[\ce{\frac{1295.6}{1.5}}\]
= 863.7 s
= 14 min 24 s
\[\ce{Cu^{2+} + 2e^- -> Cu}\]
i.e., 2 × 96500 C deposits Cu = 63.5 g
So 1295.6 C will deposit Cu = \[\ce{\frac{63.5 \times 1295.6}{2 \times 96500}}\]
= 0.4263 g
Similarly, \[\ce{Zn^{2+} + 2e^- -> Zn}\]
Mass of zinc deposited = \[\ce{\frac{65.4 \times 1295.6}{2 \times 96500}}\]
= 0.44 g
उत्तर २
Given: W = 1.45 g,
I = 1.5 amp,
t = ?
Atomic mass of Ag = 107.9
Valency of Ag = 1
Equivalent mass of Ag = `107.9/1` = 107.9
Z = `107.9/96500`
According to Faraday’s first law of electrolysis,
W = ZIt
∴ t = `W/(Z xx I)`
= `1.45/(107.9/96500 xx 1.5)`
= `(1.45 xx 96500)/(107.9 xx 1.5)`
= 864.5 seconds
= 14.41 min
According to Faraday’s second law of electrolysis,
`(W_(Zn))/W_(Ag) = E_(Zn)/E_(Ag)`
⇒ WZn = `(W_(Ag) * E_(Zn))/E_(Ag)`
= `(1.45 xx 65.38/2)/107.9` ...(At mass: Zn = 65.38)
= 0.439
Similarly,
WCu = `(W_(Ag) * E_(Cu))/E_(Ag)`
= `(1.45 xx 63.55/2)/107.9` ...(At mass: Cu = 63.55)
= 0.427 g
APPEARS IN
संबंधित प्रश्न
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
96500 coulombs correspond to the charge on how many electrons?
Write any four applications of electrochemical series
How much electricity in terms of Faraday is required to produce 20 g of Ca from molten CaCl2?
(Given: Molar mass of Calcium is 40 g mol−1.)
Number of faradays of electricity required to liberate 12 g of hydrogen is:
If a current of 0.5 ampere flows through a metallic wire for 2 hours, then how many electrons would flow through the wire?
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.
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
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 ?
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.
Consider the figure and answer the following question.
Cell ‘A’ has ECell = 2V and Cell ‘B’ has ECell = 1.1V which of the two cells ‘A’ or ‘B’ will act as an electrolytic cell. Which electrode reactions will occur in this cell?
What is the quantity of electricity in Coulombs required to produce 4.8 g of Mg from molten MgCl2? How much Ca will be produced if the same amount of electricity was passed through molten CaCl2? (Atomic mass of Mg = 24 u, atomic mass of Ca = 40 u).
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).
