A current is passed through two voltameters connected in series. The first voltmeter connected in series. The first voltmeter contains XSO4(aq) while the second voltmeter contains Y2SO4(aq). The relative atomic masses of X and Y are in the ratio of 2:1. The ration of the mass of X liberated to the mass of Y liberated is:
1. 1:1
2. 1:2
3. 2:1
4. none of these
The change in reduction potential of a hydrogen electrode when its solution initialy at pH = 0 is neutralised to pH = 7, is a/an-
1. | Increase by 0.059 V | 2. | Decrease by 0.059 V |
3. | Increase by 0.41 V | 4. | Decrease by 0.41 V |
The cell reaction for the given cell is spontaneous if:
Ptcl2|cl-(1M)||Cl-(1M)|PtCl2
1. P1 > P2
2. P1 < P2
3. P1 = P2
4. P1 = 1 atm
When a lead storage battery is discharged, then:
1. SO2 is evolved.
2. Lead is formed.
3. Lead sulphate is consumed.
4. Sulphuric acid is consumed.
A depolariser used in dry cell batteries is:
1. Ammonium chloride
2. Manganese dioxide
3. Potassium hydroxide
4. Sodium phosphate
By how much will the potential of half cell Cu2+| Cu change if the solution is diluted to 100 times at 298 K. It will -
1. | Increase by 59 mV | 2. | Decrease by 59 mV |
3. | Increase by 29.5 mV | 4. | Decrease by 29.5 mV |
The potential of the following concentration cell at room temperature is-
(1) -0.118V
(2) -0.0591V
(3) 0.118V
(4) 0.0591V
A button cell used in watches functions as following
Zn(s) + Ag2O(s) + H2O (l) 2Ag(s) + Zn2+(aq) + 2OH-(aq)
If half cell potentials are
The cell potential will be
1. 0.84 V
2. 1.34 V
3. 1.10 V
4. 0.42 V
A hypothetical electrochemical cell is shown below A l A+ (xM)l l B+ (yM) l B
The Emf measured is +0.20 V.The cell reaction is:-
(1) A+ + B → A + B+
(2) A+ + e- → A ; B+ + e- → B
(3) the cell reaction cannot be predicted
(4) A + B+ → A+ + B
The E° in the given diagram is,
(1) 0.5
(2) 0.6
(3) 0.7
(4) 0.8
Which of the following cell can produce more electric work.
(1) pt,H2|NH4Cl||0.1MCH3COOH|H2,pt
(2) pt,H2|0.1MHCl||0.1MNaOH|H2,pt
(3) pt,H2|0.1MHCl||0.1MCH3COOK|H2,pt
(4) pt,H2|0.1MCH3COOK||0.1MHCl|H2,pt
A current of 0.1A was passed for 2hr through a solution cuprocyanide and 0.3745g f copper was deposited on the cathode. Calculate the current efficiency for the copper deposition.
(1) 79%
(2) 39.5%
(3) 63.25%
(4) 63.5%
Calculate the useful work of the reaction Ag(s) + 1/2Cl2(g) AgCl(s)
Given
If = 1 atmand T = 298 K
(1) 110 kJ/mol
(2) 220 kJ/mol
(3) 55kJ/mol
(4) 1000 kJ/mol
A cell Ag | Ag+ || Cu++ | Cu initially contains 2M Ag+ and 2M Cu++ ions. The charger in cell potential after the passage of 10 amp current for 4825 sec is:
(1) –0.000738 V
(2) –1.00738
(3) –0.0038 V
(4) none
For the cell (at 298 K)
Ag(s) | AgCl(s) | Cl–(aq) || AgNO3(aq) | Ag(s)
Which of the following is correct –
(1) The cell emf will be zero when [Ag+]a = [Ag+]c ([Ag+] in anodic compartment = [Ag+] in cathodic compartment)
(2) The amount of AgCl(s) precipitate in anodic compartment will decrease with the working of the cell.
(3) The concentration of [Ag+] = constant, in anodic compartment during working of cell.
(4) Ecell = E°Ag+ | Ag –E°Cl–|AgCl|Ag
How much current is necessary to produce gas at the rate of 1 per second under STP ?
(A) 4.305 amp
(B) 17.22 amp
(C) 8.61 amp
(D) 2.1525 amp.
The cell reaction for the given cell is spontaneous if-
A galvanic cell is composed of two hydrogen electrodes, one of which is a standard one. In which of the following solutions should the other electrode be immersed to get maximum emf.
A hydrogen electrode is immersed in a solution with pH = 0 (HCl). By how much will the potential (reduction) change if an equivalent amount of NaOH is added to the solution.
(1) increase by 0.41 V
(2) increase by 59 mV
(3) decrease by 0.41 V
(4) decrease by 59 mV
The solubility product of silver iodide is and the standard potential (reduction) of Ag, electrode is + 0.800 volts at The standard potential of Ag, AgI/ electrode (reduction) from these data is-
(1) – 0.30 V
(2) + 0.15 V
(3) + 0.10 V
(4) – 0.15 V
Acidified water is electrolyzed using an inert electrode. The volume of gases liberated at
STP is 0.168L. The quantity of charge passed through the acidified water would be:
(1) 96,500 C
(2) 9,650 C
(3) 965 C
(4) 168 C
Calculate the energy obtainable from a lead storage battery in which 0.1 mol lead is consumed. Assume a constant concentration of 10.0 M
(1) 42.8 kJ
(2) 12.8 kJ
(3) 32.3 kJ
(4) 20.2 kJ
Pure water is saturated with pure solid AgCl, a silver electrode is placed in the solution and the potential is measured against normal calomel electrode at . This experiment is then repeated with a saturated solution of AgI. If the difference in potential in the two cases is 0.177 V. What is the ratio of solubilities of AgCl and AgI at the temperature of the experiment ?
A hydrogen electrode X was placed in a buffer solution of sodium acetate and acetic acid in the ratio a : b and another hydrogen electrode Y was placed in a buffer solution of sodium acetate and acetic acid in the ratio b : a. If reduction potential values for two cells are found to be respectively with respect to standard hydrogen electrode, the value of the acid can be given as
(1)
(2)
(3)
(4)
A flashlight cell has the cathodic reaction
If the flashlight cell is to give out 4.825 mA, how long could it run if initially 8.7 g of the
limiting reagent is present? [Mn = 55, O = 16]
(1)
(2)
(3)
(4)