Question 1

In an electrochemical cell, which electrode is the site of oxidation?

Accepted Answer

The anode is where oxidation occurs (loss of electrons), while the cathode is where reduction occurs.

Question 2

What is the standard cell potential (E°cell) if E°cathode = +0.80 V and E°anode = −0.44 V?

Accepted Answer

E°cell = E°cathode − E°anode = 0.80 − (−0.44) = 1.24 V.

Question 3

Which of the following statements is true for a galvanic cell?

Accepted Answer

In a galvanic cell, electrons generated at the anode travel through the external circuit to the cathode.

Question 4

In the electrolysis of molten NaCl, the product formed at the cathode is:

Accepted Answer

At the cathode (reduction site), Na⁺ ions gain electrons to form sodium metal: Na⁺ + e⁻ → Na.

Question 5

If 96,500 C of charge is passed through a CuSO₄ solution using copper electrodes, what mass of copper is deposited at the cathode? (Molar mass of Cu = 64 g/mol)

Accepted Answer

Using Faraday's law: mass = (charge × molar mass)/(n × Faraday constant) = (96,500 × 64)/(2 × 96,500) = 64 g.

Question 6

What is the standard electrode potential of a hydrogen electrode at 25°C and 1 atm pressure?

Accepted Answer

The standard hydrogen electrode (SHE) is defined as the reference electrode with a potential of exactly 0.00 V by convention.

Question 7

In an electrochemical cell, oxidation occurs at the _____ and reduction occurs at the _____.

Accepted Answer

Oxidation (loss of electrons) occurs at the anode, while reduction (gain of electrons) occurs at the cathode in any electrochemical cell.

Question 8

Calculate the number of Faradays required to deposit 6.4 g of copper (Cu = 64) from a copper(II) salt solution.

Accepted Answer

Cu²⁺ + 2e⁻ → Cu; moles of Cu = 6.4/64 = 0.1 mol; electrons required = 0.1 × 2 = 0.2 F.

Question 9

Which of the following is NOT a primary cell?

Accepted Answer

Lead-acid battery is a secondary (rechargeable) cell, while all others are primary (non-rechargeable) cells.

Question 10

If the standard cell potential (E°cell) of a galvanic cell is +1.10 V, which statement is true?

Accepted Answer

When E°cell > 0, ΔG° is negative, indicating a spontaneous reaction in a galvanic cell.

Question 11

In the Nernst equation, what does the 'n' represent?

Accepted Answer

In the Nernst equation E = E° - (RT/nF) ln Q, 'n' is the number of moles of electrons transferred per mole of reaction.

Question 12

What is the relationship between ΔG° and E°cell for an electrochemical cell?

Accepted Answer

The thermodynamic relationship for electrochemical cells is ΔG° = -nFE°cell, where n is electrons transferred and F is Faraday constant.

Question 13

During the electrolysis of aqueous NaCl solution with inert electrodes, chlorine gas is evolved at the anode. What is the electrode reaction?

Accepted Answer

Chloride ions are preferentially oxidized at the anode over water due to their lower oxidation potential, producing Cl₂ gas and releasing electrons.

Agniveer (All) Electrochemistry

Electrochemistry — Practice Questions