Electrochemistry

🔬 Chapter 7: Redox Reactions 🔬

• Learning Outcomes 🎯:

  • Calculate oxidation numbers of elements in compounds and ions.

  • Describe and explain redox processes in terms of electron transfer and changes in oxidation number.

  • Use changes in oxidation numbers to help balance chemical equations.

• What is a Redox Reaction? 🔄:

  • Oxidation is the gain of oxygen by an element or the loss of electrons.

  • Reduction is the loss of oxygen or the gain of electrons.

  • Redox reactions involve both oxidation and reduction processes.

  • Oxidation and reduction always take place together in redox reactions.

  • Redox reactions are crucial in various natural processes such as photosynthesis and respiration.

• Oxidation Numbers and Electron Transfer ⚖️:

  • Oxidation numbers can be used to determine whether a substance has been oxidized or reduced during a chemical reaction.

  • An increase in oxidation number indicates oxidation, while a decrease indicates reduction.

  • Redox reactions can also be explained in terms of electron loss (oxidation) or electron gain (reduction).

• Balancing Redox Reactions 🧮:

  • Half-equations can be used to represent the oxidation and reduction processes separately.

  • Balancing redox reactions involves ensuring that the number of electrons lost in the oxidation process is equal to the number of electrons gained in the reduction process.

• Examples of Redox Reactions 🧪:

  • The reaction between magnesium and oxygen to form magnesium oxide is an example of a redox reaction.

  • The reaction between sodium and chlorine to form sodium chloride involves the transfer of electrons and is also a redox reaction.

  • Rusting is an oxidation reaction that involves the reaction of iron with oxygen in the presence of water.