Advertisements
Advertisements
Question
A current of 1.608A is passed through 250 mL of 0.5 M solution of copper sulphate for 50 minutes. Calculate the strength of Cu2+ after electrolysis assuming volume to be constant and the current efficiency is 100%.
Advertisements
Solution
Given I = 1.608A
t = 50 min = 50 × 60 = 3000 S
V = 250 mL
C = 0.5M
η = 100%
Calculate the number of Faradays of electricity passed through the CuSO4 solution
Q = It
Q = 1.608 × 3000
Q = 4824 C
∴ Number of Faradays of electicity = `(4824 "C")/(96500 "C")` = 0.05F
Electrolysis of CuSO4
\[\ce{Cu^{2+}_{( aq)} + 2e^- -> Cu_{(s)}}\]
The above equation shows that 2F electricity will deposit 1 mole of Cu2+ to Cu.
∴ 0.05F electricity will deposit
`(1 "mol")/(2"F") xx 0.05 "F"` = 0.025 mol
Initial number of molar of Cu2+ in 250 ml of solution
= `0.5/(1000 "mL") xx 250 "mL"`
= 0.125 mol
∴ Number of moles of Cu2+ after electrolysis
= 0.125 − 0.025
= 0.1 mol
∴ Concentration of Cu2+
= `(0.1 "mol")/(250 "mL") xx 1000 "mL"`
= 0.4 M
APPEARS IN
RELATED QUESTIONS
During electrolysis of molten sodium chloride, the time required to produce 0.1 mole of chlorine gas using a current of 3A is ___________.
The number of electrons delivered at the cathode during electrolysis by a current of 1A in 60 seconds is ____________.
(charge of electron = 1.6 × 10−19 C)
Among the following cells
I) Leclanche cell
II) Nickel – Cadmium cell
III) Lead storage battery
IV) Mercury cell
Primary cells are:
In \[\ce{H2 - O2}\] fuel cell the reaction occurs at cathode is:
For the cell reaction
\[\ce{2Fe^{3+}_{( aq)} + 2l^-_{( aq)} -> 2Fe^{2+}_{( aq)} + l2_{( aq)}}\]
\[\ce{E^0_{cell}}\] = at 298 K. The standard Gibbs energy (∆G°) of the cell reactions is:
State Faraday’s Laws of electrolysis.
Calculate the standard emf of the cell: \[\ce{Cd|Cd^{2+}||Cu^{2+}|Cu}\] and determine the cell reaction. The standard reduction potentials of Cu2+|Cu and Cd2+|Cd are 0.34 V and −0.40 volts respectively. Predict the feasibility of the cell reaction.
The same amount of electricity was passed through two separate electrolytic cells containing solutions of nickel nitrate and chromium nitrate respectively. If 2.935 g of Ni was deposited in the first cell. The amount of Cr deposited in the another cell?
Given: molar mass of Nickel and chromium are 58.74 and 52 gm−1 respectively.
8.2 × 1012 litres of water is available in a lake. A power reactor using the electrolysis of water in the lake produces electricity at the rate of 2 × 106 Cs−1 at an appropriate voltage. How many years would it like to completely electrolyse the water in the lake? Assume that there is no loss of water except due to electrolysis.
Derive an expression for the Nernst equation.
