Advertisements
Advertisements
प्रश्न
How many faradays of electricity are required to produce 6 g of Mg from MgCl2?
Advertisements
उत्तर
Mg2+ + 2e- → Mg(s)
1 mole Mg2+ equals 2 mole e- for electrosis
1 mole Mg required 2 Faraday electricity
rquired 2 faraday electricity
6g Mg will require = `(2 xx 6)/24`
= 0.5 F
APPEARS IN
संबंधित प्रश्न
Derive a relation between ΔH and ΔU for a chemical reaction. Draw neat labelled diagram of calomel electrode. Resistance and conductivity of a cell containing 0.001 M KCI solution at 298K are 1500Ω and 1.46x10-4 S.cm-1 respectively.
Can you store copper sulphate solutions in a zinc pot?
Arrange the following metals in the order in which they displace each other from the solution of their salts.
\[\ce{Al, Cu, Fe, Mg}\] and \[\ce{Zn}\]
Write cathode and anode reaction in a fuel cell.
Among Zn and Cu, which would occur more readily in nature as metal and which as an ion?
Define the following term:
Fuel cell
For the electrochemical cell:
\[\ce{M | M+ || X- | X}\];
\[\ce{E^{\circ}_{{M^{+}/{M}}}}\] = 0.44 V,
\[\ce{E^{\circ}_{X/X^-}}\] = 0.33 V
Which of the following is TRUE for this data?
A solution of Cu(NO3)2 is electrolyzed between platinum electrodes using 0.1 Faraday electricity. How many moles of Cu will be deposited at the cathode?
If one mole electrons is passed through the solutions of CrCl3, AgNO3 and NiSO4, in what ratio Cr, Ag and Ni will be deposited at the electrodes?
A current strength of 3.86 A was passed through molten Calcium oxide for 41minutes and 40 seconds. The mass of Calcium in grams deposited at the cathode is (atomic mass of Ca is 40g/mol and 1F = 96500 C).
Zinc can be coated on iron to produce galvanized iron but the reverse is not possible. It is because ____________.
Assertion: pure iron when heated in dry air is converted with a layer of rust.
Reason: Rust has the compositionFe3O4.
In the electrochemical cell: Zn|ZnSO4 (0.01 M)||CuSO4 (1.0 M)|Cu, the emf of this Daniel cell is E1. When the concentration of ZnSO4 is changed to 1.0 M and that CuSO4 changed to 0.01 M, the emf changes to E2. From the above, which one is the relationship between E1 and E2?
Consider the change in the oxidation state of Bromine corresponding to different emf values as shown in the expression below:
\[\ce{BrO^-_4 ->[1.82 V] BrO^-_3 ->[1.5 V] HBrO ->[1.595 V] Br2 ->[1.0652 V] Br^-}\]
Then the species undergoing disproportionation is:
Define anode
Define cathode
Why is anode in galvanic cell considered to be negative and cathode positive electrode?
Can Fe3+ oxidises bromide to bromine under standard conditions?
Given: \[\ce{E^0_{{Fe^{3+}|Fe^{2+}}}}\] = 0.771 V
\[\ce{E^0_{{Br_{2}|Br^-}}}\] = −1.09 V
Is it possible to store copper sulphate in an iron vessel for a long time?
Given: \[\ce{E^0_{{Cu^{2+}|{Cu}}}}\] = 0.34 V and \[\ce{E^0_{{Fe^{2+}|{Fe}}}}\] = −0.44 V
Two metals M1 and M2 have reduction potential values of −xV and +yV respectively. Which will liberate H2 and H2SO4.
Reduction potential of two metals M1 and M2 are \[\ce{E^0_{{M_1^{2+}|M_1}}}\] = −2.3 V and \[\ce{E^0_{{M_2^{2+}|M_2}}}\] = 0.2 V. Predict which one is better for coating the surface of iron.
Given: \[\ce{E^0_{{Fe^{2+}|Fe}}}\] = −0.44 V
For the cell \[\ce{Mg_{(s)}|Mg^{2+}_{( aq)}||Ag^+_{( aq)}|Ag_{(s)}}\], calculate the equilibrium constant at 25°C and maximum work that can be obtained during operation of cell.
Given: \[\ce{E^0_{{Mg^{2+}|Mg}}}\] = −2.37 V and \[\ce{E^0_{{Ag^{+}|Ag}}}\] = 0.80 V
Use the data given in below find out the most stable ion in its reduced form.
`"E"_("Cr"_2"O"_7^(2-)//"Cr"^(3+))^⊖`= 1.33 V `"E"_("Cl"_2//"Cl"^-)^⊖` = 1.36 V
`"E"_("MnO"_4^-//"Mn"^(2+))^⊖` = 1.51 V `"E"_("Cr"^(3+)//"Cr")^⊖` = - 0.74 V
The quantity of charge required to obtain one mole of aluminium from Al2O3 is ______.
For the given cell, \[\ce{Mg | Mg^{2+} || Cu^{2+} | Cu}\]
(i) \[\ce{Mg}\] is cathode
(ii) \[\ce{Cu}\] is cathode
(iii) The cell reaction is \[\ce{Mg^+ Cu^{2+} -> Mg^{2+} + Cu}\]
(iv) \[\ce{Cu}\] is the oxidising agent
Can absolute electrode potential of an electrode be measured?
What is electrode potential?
Match the terms given in Column I with the units given in Column II.
| Column I | Column II |
| (i) Λm | (a) S cm-¹ |
| (ii) ECell | (b) m-¹ |
| (iii) K | (c) S cm2 mol-¹ |
| (iv) G* | (d) V |
Match the items of Column I and Column II.
| Column I | Column II |
| (i) K | (a) I × t |
| (ii) Λm | (b) `Λ_m/Λ_m^0` |
| (iii) α | (c) `K/c` |
| (iv) Q | (d) `G^∗/R` |
Assertion: Mercury cell does not give steady potential.
Reason: In the cell reaction, ions are not involved in solution.
The electrochemical cell stops working after some time because
Calculate the standard EMF ofa cell which involves the following cell reactions
\[\ce{Zn + 2 Ag+ -> Zn^{2+} + 2 Ag}\]
Given that \[\ce{E^{o}_{Zn/Zn^{2+}}}\] = 0.76 volt and \[\ce{E^{o}_{Ag/Ag^{+}}}\] = – 0.80 volt.
Which of the following statements about galvanic cell is incorrect
A current of 2.0 ampere passed for 5 hour through a molten salt deposits 22 g of the metal (Atomic mass = 177). The oxidation state of the metal in the metal salt is
Standard reduction electrode potentials of three metals A, B and C are respectively + 0.5 V, – 3.0 V. and – 1.2 V. The reducing powers of there metal is.
Given the data at 25°C
\[\ce{Ag + I- -> AgI + e-}\]; E° = – 0.152 V
\[\ce{Ag -> Ag+ + e-}\]; E° = – 0.800 V
The value of log Ksp for AgI is ______.
Cell reaction is spontaneous when
If 0.5 amp current is passed through acidified silver nitrate then in 100 minutes the mass of silver, deposite on cathode is (eq. wt. of silver nitrate + 108).
If the value of Ksp for Hg2Cl2 (s) is X then the value of X will be ____ where pX = - log X.
Given:
\[\ce{Hg2Cl2 + 2e- -> 2Hg(l) + 2Cl-}\], E° = 0.27 V
\[\ce{Hg+2 + 2e- -> 2Hg(l)}\] E° = 0.81 V
Which of the following is incorrect?
In a solution of CuSO4, how much time will be required to precipitate 2 g copper by 0.5 ampere current?
The two half cell reaction of an electrochemical cell is given as
\[\ce{Ag+ + e- -> Ag}\], `"E"_("Ag"^+//"Ag")^circ` = - 0.3995 V
\[\ce{Fe^{2+} -> Fe^{3+} + e-}\], `"E"_("Fe"^{3+}//"Fe")^{2+}` = - 0.7120 V
The value of EMF will be ______.
Galvanic cell is a device in which ______.
Can we construct an electrochemical cell with two half-cells composed of ZnSO4 solution and zinc electrodes? Explain your answer.
The cell constant of a conductivity cell is 0.146 cm-1. What is the conductivity of 0.01 M solution of an electrolyte at 298 K, if the resistance of the cell is 1000 ohm?
Explain why the anode is of negative polarity in a galvanic cell.
What are electrochemical reactions?
Explain the types of electrochemical cells.
State the term for the following:
Two metal plates or wires through which the current enters and leaves the electrolytic cell.
