Electrochemistry and Hydrogen Fuel Cells

electrochemistry, hydrogen fuel cells, redox reactions, and practical applications related to the lecture.

What is a redox reaction?

A redox reaction involves the transfer of electrons between substances, involving a reducing agent and an oxidizing agent.

What are the roles of the reducing agent and oxidizing agent in redox reactions?

The reducing agent is the electron donor, while the oxidizing agent is the electron acceptor.

What is the function of an electrochemical cell?

An electrochemical cell converts chemical energy into electrical energy (voltaic) or electrical to chemical energy (electrolytic).

What are the two main electrodes in an electrochemical cell?

Anode (where oxidation occurs) and Cathode (where reduction occurs).

What is an example of a real-life application of redox reactions?

E-waste recovery, where redox reactions are used to extract valuable metals from electronic waste.

What is the equation for the reaction in a hydrogen fuel cell?

H2 (g) + O2 (g) → H2O (l) with a voltage of 1.23 V.

How is green hydrogen generated?

Green hydrogen is generated through electrolysis, splitting water into hydrogen and oxygen using electricity from a green source.

What type of cell is used in the electrolysis process?

Electrolytic cell.

What is Faraday's first law of electrochemistry?

The mass of a substance produced or consumed at an electrode is proportional to the electric charge passed through the cell.

What is Faraday's constant?

Faraday's constant (F) is 96,485 C mol-1, which represents the charge on one mole of electrons.

What is the relationship between electric current, charge, and time?

Electric current (I) is the amount of charge (Q) flowing through a circuit per unit time (t), expressed as I = Q/t.

What is the reaction at the cathode during the electrowinning of copper?

Cu2+ + 2e- → Cu with E_cathode = 0.34 V.

Describe the process of electrowinning.

Electrowinning involves using an electrolytic cell where metal ions are deposited onto the cathode from an aqueous electrolyte.

What type of electrochemical reaction occurs when electricity is used to drive a nonspontaneous reaction?

An electrolytic reaction.

How do we calculate the amount of charge in coulombs from current?

Charge (Q) can be calculated by multiplying current (I) in amperes by time (t) in seconds: Q = I × t.

In electrochemistry, what happens at the anode?

Oxidation occurs at the anode.

What are common applications of fuel cells?

Fuel cells are used to generate electricity efficiently by employing redox reactions.

What is the significance of measuring electric current in electrochemistry?

Measuring electric current helps calculate the mass of metals produced or consumed based on Faraday’s laws.

What does the term 'clean hydrogen' refer to?

Clean hydrogen refers to hydrogen produced through environmentally friendly methods, such as green and blue hydrogen.

How is hydrogen fuel considered sustainable?

Hydrogen fuel is considered sustainable because it generates zero emissions when used and can be produced from renewable energy sources.

In the electrochemical cell Zn(s)|Zn2+(aq)||Ag+(aq)|Ag(s), if the current is 0.52 A for 75 minutes, how is the mass of Zn determined?

First calculate total charge (Q), then use Faraday's laws to find moles of electrons, and finally convert to mass of Zn.