Chemistry · Physics

Electrochemistry and Current Electricity

272 Questions

Review fundamental concepts of electrochemistry and current electricity through these practice questions. The set includes numerical problems on electrolysis, drift velocity, and electrode potentials. These topics frequently appear in engineering, CSIR NET, and state PSC prelims examinations for thorough preparation.

Electrolysis calculationsElectrode potentialNernst equationDrift velocityFuel cellsMolar conductivity

Electrochemistry and Current Electricity Questions

Multiple choice

What is the equation for the Nernst equation?

  1. E = E° - (RT/nF)lnQ

  2. E = E° + (RT/nF)lnQ

  3. E = E° - (nF/RT)lnQ

  4. E = E° + (nF/RT)lnQ
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The Nernst equation relates the electromotive force of a cell to the concentrations of the reactants and products of the cell reaction.

Multiple choice

What are the two main components of a redox flow battery?

  1. Anode and cathode

  2. Positive and negative electrodes

  3. Electrolyte and separator

  4. Current collector and terminals
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Redox flow batteries consist of two tanks containing electrolyte solutions, separated by a membrane or separator.

Multiple choice

What is the typical efficiency range of redox flow batteries?

  1. 60-70%

  2. 70-80%

  3. 80-90%

  4. 90-100%
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Redox flow batteries typically have an efficiency range of 70-80%, meaning that 70-80% of the electrical energy input during charging is recovered during discharging.

Multiple choice

What is the typical depth of discharge (DOD) for redox flow batteries?

  1. 20-30%

  2. 50-60%

  3. 70-80%

  4. 90-100%
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Redox flow batteries typically have a DOD of 70-80%, meaning that they can discharge up to 70-80% of their stored energy before needing to be recharged.

Multiple choice

What is the Nernst equation, and what does it describe?

  1. Relates the cell potential to the concentrations of reactants and products

  2. Relates the cell potential to the temperature and pressure

  3. Relates the cell potential to the electrode materials

  4. Relates the cell potential to the current flowing through the cell
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The Nernst equation is a mathematical expression that relates the cell potential of an electrochemical cell to the concentrations of reactants and products involved in the cell reaction.

Multiple choice

What is the role of a salt bridge in an electrochemical cell?

  1. Completes the electrical circuit between the electrodes

  2. Prevents the mixing of solutions in the half-cells

  3. Maintains a constant pH in the solutions

  4. Provides a source of ions for the cell reaction
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The salt bridge in an electrochemical cell completes the electrical circuit between the electrodes, allowing the flow of ions and maintaining electrical neutrality in the cell.

Multiple choice

What is the primary function of a battery?

  1. To generate electricity from chemical energy

  2. To store electrical energy as chemical energy

  3. To convert mechanical energy into electrical energy

  4. To convert thermal energy into electrical energy
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The primary function of a battery is to store electrical energy in the form of chemical energy, which can be released later to generate electricity.

Multiple choice

What is the basic principle behind fuel cells?

  1. Conversion of chemical energy into electrical energy through electrochemical reactions

  2. Conversion of electrical energy into chemical energy through electrochemical reactions

  3. Conversion of mechanical energy into electrical energy through electrochemical reactions

  4. Conversion of thermal energy into electrical energy through electrochemical reactions
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Fuel cells operate on the principle of converting chemical energy stored in fuels, such as hydrogen or methanol, into electrical energy through electrochemical reactions.

Multiple choice

Which of the following is a type of battery that uses lithium ions as the charge carrier?

  1. Lead-acid battery

  2. Nickel-cadmium battery

  3. Lithium-ion battery

  4. Sodium-sulfur battery
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Lithium-ion batteries are a type of rechargeable battery that uses lithium ions as the charge carrier. They are commonly used in portable electronic devices such as laptops, smartphones, and electric vehicles.

Multiple choice

What is the primary function of a fuel cell?

  1. To generate electricity from chemical fuels

  2. To store electrical energy

  3. To convert heat into electricity

  4. To produce hydrogen gas
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Fuel cells are electrochemical devices that generate electricity from chemical fuels, such as hydrogen and oxygen. They are often used in portable power applications and as backup power sources.

Multiple choice

Which of the following is a type of battery that uses sodium ions as the charge carrier?

  1. Lead-acid battery

  2. Nickel-cadmium battery

  3. Lithium-ion battery

  4. Sodium-ion battery
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Sodium-ion batteries are a type of rechargeable battery that uses sodium ions as the charge carrier. They are similar to lithium-ion batteries, but they use sodium instead of lithium. Sodium is a more abundant and less expensive element than lithium, making sodium-ion batteries a potential low-cost alternative to lithium-ion batteries.

Multiple choice

What is the theoretical efficiency limit of a solid state fuel cell?

  1. 80-90%

  2. 50-60%

  3. 20-30%

  4. 10-20%
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Solid state fuel cells have a theoretical efficiency limit of 80-90%, which is higher than conventional combustion engines.

Multiple choice

What is the term used to describe the process of converting electrical energy into chemical energy in a battery?

  1. Charging

  2. Discharging

  3. Cycling

  4. Aging
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Charging refers to the process of converting electrical energy into chemical energy in a battery, which results in the storage of energy in the battery.

Multiple choice

What is the term used to describe the process of converting chemical energy into electrical energy in a battery?

  1. Charging

  2. Discharging

  3. Cycling

  4. Aging
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Discharging refers to the process of converting chemical energy stored in a battery into electrical energy, which results in the release of energy from the battery.

Multiple choice

In voltammetry, the current is plotted against which of the following?

  1. Voltage

  2. Time

  3. Concentration

  4. Temperature
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In voltammetry, the current is plotted against the voltage applied to the working electrode.