Electrolytic Cell

Q. How many grams of cobalt metal will be deposited when a solution of cobalt(II) chloride is electrolyzed with a current of $10$ amperes for $109$ minutes? $(1\text{Faraday}=96,500C;\text{Atomic mass of Co = 59 u})$

1. $4.0$
2. $20.0$
3. $40.0$
4. $0.66$

Q.

Depict the galvanic cell in which the reaction, $Zn\left(s\right)+2A{g}^{+}\left(aq\right)\to Z{n}^{2+}\left(aq\right)+2Ag\left(s\right)$ takes place . Further show :

Which of the electrode is negatively charged

The carriers of the current in the cell

Individual reaction at each electrode

Q. Three faradays of electricity are passed through molten $A{l}_2{O}_3,$ aqueous solution of $CuS{O}_4$ and molten $NaCl$ taken in different electrolytic cells. The amount of $Al,Cu$ and $Na$ deposited at the cathodes will be in the ratio of:
[Assume: $Al,Cu\text{and}Na$ are depositing at cathode]

1. 1 mole : 2 mole : 3 mole
2. 3 mole : 2 mole : 1 mole
3. 1 mole : 1.5 mole : 3 mole
4. 1.5 mole : 2 mole : 3 mole

Q. The electrode potential of hydrogen electrode is when hydronium ion concentration is 10 raise to power -5 M (pH=1 ATM)

Q.

The chemical reaction that takes place during the recharging of lead storage battery is

1. 2PbSO₄(s) + 2H₂O(l) → Pb(s) + PbO₂(s) + 2H₂SO₄(aq)

2. Pb(s) + SO₄^2-(aq) → PbSO₄(s) + 2e^-

3. PbO₂(s) + SO₄^2-(aq) + 4H⁺(aq) + 2e^- → PbSO₄(s) + 2H₂O(l)

4. Pb(s) + PbO₂(s) + 2H₂SO₄(aq) → 2PbSO₄(s) + 2H₂O(l)

Q. For the galvanic cell,

$Zn\left(s\right)+C{u}^{2+}\left(0.02M\right)\to Z{n}^{2+}\left(0.04M\right)+Cu\left(s\right)$

$E_{cell}=$ _______ $\times {10}^{-2}V$ (Nearest integer)

$[Use:E_{Cu/C{u}^{2+}}^0=-0.34V,E_{Zn/Z{n}^{2+}}^0=+0.76V,\frac{2.303RT}{F}=0.059V]$

Q. ntConsider the reactionn ntCl2(g) + 2Br-(aq) -------2Cl-(aq) +Br2n ntThe emf of the cell whenn nt[Cl-]=[Br2]=[Br-]=0.01 M and Cl2 gas at 1 atm pressure will be (E0 for the above reaction is= 0.29 volt)n nt1. 0.54 voltn nt2. 0.35 voltn nt3. 0.24 voltn nt4. -0.29 voltn

Q. $\begin{array}{cccc}& \text{List - I}& & \text{List - II}\\ \text{(P)}& \text{Very dilute solution of HCl}& \text{(1)}& O_2\text{evolved at anode}\\ \text{(Q)}& \text{Very dilute solution of KCl}& \text{(2)}& H_2\text{evolved at cathode}\\ \text{(R)}& \text{Concentrated solution of NaCl}& \text{(3)}& C{l}_2\text{evolved at anode}\\ \text{(S)}& \text{Fairly concentrated solution of}AgN{O}_3& \text{(4)}& \text{Na deposition at cathode}\\ & & \text{(5)}& \text{Ag deposition at cathode}\\ & & \text{(6)}& \text{K deposition at cathode}\end{array}$
Match each product in LIST-I with one or more reaction in LIST-II and choose the correct option.

1. $P\to 1,2;Q\to 1,2;R\to 2,3;S\to 1,5$
2. $P\to 1,2;Q\to 2,3;R\to 2,3;S\to 1,5$
3. $P\to 2,3;Q\to 3,6;R\to 3,4;S\to 1,5$
4. $P\to 2,3;Q\to 3,6;R\to 2,3;S\to 2,5$

Q.

In an electrolytic cell, the electrode connected to the negative terminal of the battery is called

1. cathode

2. anode

3. electrolyte

4. Electrolytic tank

Q. Copper is purified by electrolytic refining of blister copper. The correct statement about this process is(are)

1. Impure copper strip is used as cathode.
2. Acidified aqueous $CuS{O}_4$ is used as electrolyte.
3. Pure Cu deposits at cathode.
4. Impurities settles as anode mud

Q.

Which of the following is possible at anode during electrolysis?

1. A(s) → A⁺ (aq) + e^-

2. A⁺(aq) + e^- → A(s)

3. A²⁺(aq) + e^- → A⁺(aq)

4. A²⁺(aq) + 2e^- → A(s)

Q.

What is the Principle of Electrochemistry?

Q.

Are LEDS Reverse Biased?

Q. A semiconductor becomes an insulator at

1. $0^{\circ }C$
2. $-{100}^{\circ }C$
3. $300K$
4. $0K$

Q. Passage of three faradays of charge through an aqueous solution of $AgN{O}_3,CuS{O}_4,Al(N{O}_3{)}_3\text{and}NaCl$ will deposit metals at the cathode in the molar ratio of :

1. 1 : 2 : 3 : 1
2. 6 : 3 : 2 : 6
3. 6 : 3 : 2 : 2
4. 3 : 2 : 1 : 2

Q. Other things being equal, the life of a Daniell cell may be increased by
(1) keeping temperature low
(2) using large copper electrode
(3) decreasing concentration of copper ions
(4) using zinc electrodes

Q.

Is electroplating spontaneous or non-spontaneous?

Q. Which of the following statements are true about an electrolytic cell?

1. The reaction is non-spontaneous
2. A potential equal to the cell potential needs to be applied.
3. The flow of electrons is from anode to cathode.
4. The flow of current is from anode to cathode.

Q. Depict the galvanic cell in which the reaction $Zn\left(s\right)+2A{g}^{+}\left(aq\right)\to Z{n}^{2+}\left(aq\right)+2Ag\left(s\right)$ takes place. Further show:
(i) Which of the electrode is negatively charged?
(ii) The carriers of the current in the cell.
(iii) Individual reaction at each electrode.

Q. $10$ gram of a fairly concentrated solution of cupric sulphate is electrolysed using $0.01$ faraday of electrocity.
Calculate the mass (in gram) of the resulting solution
(Molecular mass of $Cu=63.5g$)
(give your answer upto to decimal)

Q. Which of the following statement is incorrect about mercury cell?

1. Products of the electrode reactions are separated by thin membrane
2. Anode reaction is
   $Zn\left(Hg\right)+2O{H}^{-}\to ZnO\left(s\right)+H_{2}O+2e^{-}$
3. Cell reaction is
   $Zn\left(Hg\right)+HgO\left(s\right)+O{H}^{-}\to ZnO\left(s\right)+Hg\left(l\right)+H_{2}O$
4. Used in low current devices such as electronic watches

Q. When a galvanic cell is connected to an external volatge supply ($E_{ext}$), the electrons flow from cathode to anode because

1. $E_{ext}=\text{Electrical potential of cell}$
2. $E_{ext}>\text{Electrical potential of cell}$
3. $E_{ext}<\text{Electrical potential of cell}$
4. None of these

Q.

What is observed when an external potential greater than the cell potential of the given galvanic cell is applied opposing it

Q. Which of the following statement(s) is/are true about mercury cell?

1. Products of the electrode reactions are separated by thin membrane
2. Anode reaction is
   $Zn\left(Hg\right)+2O{H}^{-}\to ZnO\left(s\right)+H_{2}O+2e^{-}$
3. Cell reaction is
   $Zn\left(Hg\right)+HgO\left(s\right)+O{H}^{-}\to ZnO\left(s\right)+Hg\left(l\right)+H_{2}O$
4. Used in low current devices such as electronic watches

Q.

Depict the galvanic cell in which the reaction $Zn\left(s\right)+2A{g}^{+}\left(aq\right)⟶Z{n}^{2+}\left(aq\right)+2Ag\left(s\right)$ takes place, further show:
Which of the electrode is negatively charged,

The carriers of the current in the cell.

Individual reaction at each electrode.

Q. Which of the following statement(s) is/are correct for a galvanic cell ?

1. Oxidation occurs at anode
2. Reduction occurs at cathode
3. The electrode at which electrons are released is called cathode
4. The electrode at which electrons are consumed is called cathode.

Q. The standard EMF of a galvanic cell can be calculated from:

1. the size of the electrode
2. the pH of the solution
3. the amount of metal in the anode
4. the $E^o$ values of the half-cells

Q. State whether the following statements are True of False:
In galvanic (voltaic) cell, the positive electrode is called cathode and the negative electrode is called anode.

1. True
2. False

Q.

Predict the products of electrolysis in each of the following:

(i) An aqueous solution of AgNO₃ with silver electrodes

(ii) An aqueous solution AgNO₃ with platinum electrodes

(iii) A dilute solution of H₂SO₄ with platinum electrodes

(iv) An aqueous solution of CuCl₂ with platinum electrodes.

Q. In the electrolysis of aqueous solution of copper (2) chloride the mass of cathode electrode is increased by 3.2 by a current .if anode is cu then at anod?