How many cc of oxygen will be liberated by 2 A current flowing fo

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501.

How many cc of oxygen will be liberated by 2 A current flowing for 3 min 13 s through acidulated water?

  • 11.2 cc

  • 33.6 cc

  • 44.8 cc

  • 22.4 cc


D.

22.4 cc

When acidulated water is electrolysed, the following reactions will take place at anode and cathode.

At cathode,

2H+ (aq) + 2e- → H2 (g)

At anode,

2H2O (l) → O2(g) + 4H+ (aq) + 4e-

The net reaction is

2H2OAcidulated water Electrolysis 2H2 (g) + O2 (g)

From the reaction of the anode, it is clear that 4F liberates oxygen = 22400 cc

 (3 × 60 / 13) × 2C electricity will liberate O2.

22400 × 193 × 24 × 96500

= 22.4 cc


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502.

Consider the following statements.
(1) Fuel cells are voltaic cell which convert electrical energy of fuel into chemical energy.

(2) Fuel cells are galvanic cells which convert chemical energy of fuel into electrical energy.

(3) The efficiency of H2-O2 fuel cell is approximately 25%.

(4) Fuel cells do not cause pollution problem.

Among these, the correct statements are

  • (2) and (3) only

  • (1) and (4) only

  • (2) and (4) only

  • (2), (3) and (4) only


503.

The standard reduction potential E° for half-reactions are

Zn → Zn2+ + 2e- ; E° = +0.76 V

Fe → Fe2+ + 2e- ; E° = +0.41 V

The EMF of the cell reaction

Fe2+ + Zn → Zn2+ + Fe is

  • +1.28 V

  • -1.28 V

  • +0.35 V

  • -0.35 V


504.

Certain electric current for half an hour can collect 11.2 L of hydrogen at NTP. Same current when passed through an electrolytic solution for one hour, can deposite how much silver?

  • 216g

  • 108 g

  • 47 g

  • 60 g


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505.

How much Coulomb needed to convert 1 mole of MnO4
into Mn2+?

  • 482500 C

  • 193000 C

  • 96500 C

  • 36500 C


506.

Aluminium is extracted by the electrolysis of

  • alumina

  • bauxite

  • molten cryolite

  • alumina mixed with molten cryolite


507.

Saturated solution of KNO3 is used to make salt bridge because

  • KNO3 is highly soluble in water

  • velocity of K+ is greater than that of NO3-

  • Velocity of NO3- 1s greater than that of K+

  • velocity of K+ and NO3- are almost equal


508.

Which of the following is a highly corrosive salt?

  • FeCl2

  • PbCl2

  • Hg2Cl2

  • HgCl2


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509.

One Faraday of charge passes through solution of AgNO3 and CuSO4 connected in series and the concentration of two solutions being in the ratio 1 : 2. The ratio of amount of Ag and Cu deposited on Pt electrode is

  • 1079.6354

  • 54.3177

  • 1079.3177

  • 54.6354


510.

On passing 0.5 Faraday of electricity through NaCl, the amount of Cl deposited on cathode is

  • 35.5 g

  • 17.75 g

  • 71 g

  • 142 g


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