Chemistry · Physics

Electrochemistry and Current Electricity

224 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 main component of the positive electrode in a Zinc-Air battery?

  1. Zinc

  2. Air

  3. Manganese dioxide

  4. Lithium cobalt oxide
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The positive electrode in a Zinc-Air battery is an air electrode, which consists of a porous material that allows oxygen from the air to react with the electrolyte.

Multiple choice

What is the main component of the negative electrode in a Zinc-Air battery?

  1. Zinc

  2. Air

  3. Manganese dioxide

  4. Lithium cobalt oxide
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The negative electrode in a Zinc-Air battery is a zinc electrode, which consists of a zinc metal anode that undergoes oxidation during discharge.

Multiple choice

Which of the following is a disadvantage of electrolysis?

  1. It produces hydrogen at high purity

  2. It is a relatively inexpensive process

  3. It is a renewable source of hydrogen

  4. It requires a lot of electricity
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Electrolysis requires a lot of electricity, which can be expensive and may come from non-renewable sources.

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 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 potential energy of a battery?

  1. $U = mgh$
  2. $U = rac{1}{2}mv^2$
  3. $U = rac{1}{2}kx^2$
  4. $U = - rac{k}{r}$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The potential energy of a battery is $U = -rac{k}{r}$, where $k$ is a constant and $r$ is the distance between the particles.

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.

Multiple choice

What is the Nernst equation?

  1. An equation that relates the electrode potential to the concentration of the analyte.

  2. An equation that relates the current to the voltage in a potentiometric cell.

  3. An equation that relates the conductivity of a solution to the concentration of the analyte.

  4. An equation that relates the mass of an analyte to the current in a coulometric cell.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The Nernst equation is an equation that relates the electrode potential to the concentration of the analyte.

Multiple choice

What is the difference between a potentiometric and a conductometric titration?

  1. In a potentiometric titration, the equivalence point is determined by measuring the change in electrode potential, while in a conductometric titration, the equivalence point is determined by measuring the change in conductivity.

  2. Potentiometric titrations are more sensitive than conductometric titrations.

  3. Conductometric titrations are more versatile than potentiometric titrations.

  4. All of the above.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In a potentiometric titration, the equivalence point is determined by measuring the change in electrode potential, while in a conductometric titration, the equivalence point is determined by measuring the change in conductivity. Potentiometric titrations are more sensitive than conductometric titrations. Conductometric titrations are more versatile than potentiometric titrations.