ECAT Chemistry Chapter 10 Electrochemistry

Purification of an impure copper is made by electrolytic cell, in which impure copper is anode and pure copper is cathode, and the electrolyte used is

• H₂SO₄ A
• CuSO₄ B
• ZnSO₄ C
• Na₂SO₄ D

The function of salt bridge in the galvanic or voltaic cell is to

• Carry out oxidation at anode A
• To carry out reduction at cathode B
• Carry out electrolysis C
• To prevent the net charge accumulation in either of the half cells D

The process of electrical coating of one metal on another to protect, decorate or to have greater resistance to corrosion is called

• Electroplating A
• Electrolysis B
• Conduction C
• Induction D

A certain current liberate 0.5 g of hydrogen in 2 h. How many grams of copper can be liberated by the same time in a copper sulphate solution?

• 12.7 gm A
• 15.9 gm B
• 31.8 gm C
• 63.5 gm D

The oxidation number of H is -1 in the compound

• H₂O A
• H₃BO₃ B
• NaOH C
• NaH D

In passage of electricity through aqueous solution of AgNO₃silver dissolves at anode to form Ag⁺, the electrodes are

• Silver metal A
• Pt metal B
• Graphite C
• Copper metal D

An electrochemical cell is based upon

• Acid-base reaction A
• Redox reaction B
• Nuclear reaction C
• None of the above D

The reference calomel electrode is made from which of the following?

• ZnCl₂ A
• CuSO₄ B
• Hg₂Cl₂ C
• HgCl₂ D

Ionization is the process in which ionic compounds when fused or dissolved in water split up into charged particles called :

• Atoms. A
• Electrons. B
• Protons . C
• Ions D

• Adding H₂O and H⁺ions A
• Adding OH^-ions B
• Adding O²molecules C
• Adding O atoms D

When electrically is passed through molten Al₂O₃+ Na₃AlF₆and 13.5 gms of Al are deposited, the number of farady must be

• 0.5 A
• 1.0 B
• 1.5 C
• 2.0 D

When quantity of electricity passed is one faraday then the mass deposited at the electrode is equal to

• One gm, atomic weight A
• One gm, Equivalent B
• Eletrochemical equivalent C
• None of the above D

• Cu A
• H B
• N C
• O D

A half reaction can be defines as :

• It always occurs at cathode. A
• Involves only half of a mole of electrolyte. B
• Occurs at one of the electrode. C
• Goes only half way to completion. D

Silver oxide battery has a voltage of

• 2.0 V A
• 1.5 V B
• 2.5 V C
• 1.0 V D

When electricity is passed through molten electrolyte consisting of alumina and cryolite, 13.5 g of Al are deposited. The number of faradays of electricity passed must be

• 2.0 A
• 1.5 B
• 1.0 C
• 0.5 D

Time required to deposit one millimole of aluminium metal by the passage of 9.65 amperes through molten electrolyte containing aluminium ion is

• 30 s A
• 10 s B
• 30,000 s C
• 10,000 s D

A standard hydrogen electrode (S.H.E) consists of a platinized platinum electrode dipped in 1 molar solution of H⁺ions and hydrogen gas is passed at a pressure of

• One pascal A
• One kilo pascal B
• One atmoshpere C
• Then atmoshpere D

In lead accumulator the electrolyte is H₂SO₄solution is

• 30% H₂SO₄ A
• 60% H₂SO₄ B
• 80% H₂SO₄ C
• 90% H₂SO₄ D

The oxidation number of Mn is KMnO₄is

• +2 A
• +4 B
• +6 C
• +7 D

Which of the following is a strong electrolyte?

• Ca(NO₃)₂ A
• HCN B
• CH₃COOH C
• NH₄OH D

The cell which generates electricity as a result of spontaneous oxidation-reduction reaction is called

• Electrolytic cell A
• Nelson's cell B
• Galvanic cell C
• Down's cell D

The number of coulombs required for the deposition of 107.870 g of silver is

• 96500 A
• 48250 B
• 193000 C
• 10000 D

A dry alkaline cell has porous Zn anode and MnO₂as cathode the electrolyte used is

• Ca(OH)₂ A
• NaOH B
• KOH C
• NH₄OH D

An electric current is passed through silver nitrate solution using silver electrodes.10.79 g of silver was found to be deposited on the cathode if the same amount of electricity is passed through copper sulphate solution using copper electrodes, the weight of copper deposited on the cathode is

• 6.4 g A
• 2.3 g B
• 128.8 g C
• 3.2 g D

The specific conductance of a 0.1 N KCl solution at 23°C is 0.012 ohm^-1cm^-1. The resistance of cell containing the solution at the same temperature was found to be 55 ohm. The cell constant will be

• 0.142 cm^-1 A
• 0.66 cm^-1 B
• 0.916 cm^-1 C
• 1.12 cm^-1 D

Same amount of electric current is passed through solutions of AgNO₃and HCl. If 1.08 g of silver is obtained in the first case, the amount of hydrogen liberated as S.T.P in the second case is

• 112 cm³ A
• 22400 cm³ B
• 224 cm³ C
• 1.008 g D

Oxidation number of oxygen in OF₂is

• +1 A
• -1 B
• +2 C
• -2 D

The best electrode used in salt bridge is KCl. Which other electrolyte an also be used for the purpose :

• NaCl A

• NH₄NO₃

  B

• KNO₃

  C

• NaNO₃

  D

Metallic conduction is also called as :

• Ionic conduction. A
• Protonic conduction. B
• Electronic conduction C
• Super conduction D