Advertisements
Advertisements
Question
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).
Advertisements
Solution
\[\ce{Mg^{2+} + 2e- -> Mg}\]
1 mole of magnesium ions gains two moles of electrons or 2F to form 1 mole of Mg 24 g Mg requires 2F electricity.
4.8 g Mg requires `2 × 4.8/24` = 0.4F = 0.4 × 96500 = 38600 C
\[\ce{Ca^{2+} + 2e^{-} -> Ca}\]
2F electricity is required to produce 1 mole = 40 g Ca
0.4F electricity will produce 8 g Ca.
APPEARS IN
RELATED QUESTIONS
96500 coulombs correspond to the charge on how many electrons?
If a current of 0.5 ampere flows through a metallic wire for 2 hours, then how many electrons would flow through the wire?
How much charge is required for the following reduction?
1 mol of Cu2+ to Cu.
Write any two uses of H2SO4
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
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.
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.
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:
