lecture 4 - redox Flashcards
What are the aims of studying REDOX reactions?
To understand different types of chemical reactions and balance oxidation-reduction reactions.
What defines an aqueous solution?
A solution where water is the solvent.
Why is water significant in chemical reactions?
It dissolves various substances, acting as a solvent to form solutions.
What are the components of a solution?
• Solvent: Dissolves other substances.
• Solute: Substance dissolved.
How can you characterize solutions in terms of conductivity?
By their ability to conduct electricity, depending on the presence and degree of ionization of electrolytes.
What is the difference between strong and weak electrolytes?
• Strong Electrolytes: Fully ionized in water, high conductivity.
• Weak Electrolytes: Partially ionized, low conductivity.
What are the three main types of chemical reactions covered in this topic?
Precipitation, acid-base, and oxidation-reduction (REDOX) reactions.
What happens during a precipitation reaction?
Two solutions mix, forming an insoluble solid (precipitate).
What is required to describe a precipitation reaction?
Balanced chemical equations with the identities of reactants and products.
What precipitate forms when lead nitrate reacts with sodium iodide?
A yellow precipitate (Lead iodide).
How can the product of a precipitation reaction be predicted?
Using solubility rules and the net charge of the products.
What characterizes REDOX reactions?
Transfer of electrons between chemical species.
Define oxidation and reduction.
• Oxidation: Loss of electrons (increase in oxidation number).
• Reduction: Gain of electrons (decrease in oxidation number).
What is the mnemonic for remembering REDOX processes?
OILRIG: Oxidation Is Loss, Reduction Is Gain.
What are oxidation numbers, and how are they used?
Positive or negative numbers used to track electron transfers in REDOX reactions.
What is the role of oxidizing and reducing agents?
• Oxidizing Agent: Gains electrons (reduced).
• Reducing Agent: Loses electrons (oxidized).
What are the steps to balance REDOX reactions?
- Identify half-reactions.
- Balance atoms, oxygen, and hydrogen.
- Add electrons to balance charges.
- Combine half-reactions.
How do you balance REDOX reactions in basic solutions?
Convert H⁺ ions to H₂O and balance with OH⁻ ions.
Why is the half-reaction method useful?
It separates oxidation and reduction processes, making it easier to balance REDOX equations.
How are oxidation numbers assigned in covalent compounds?
By arbitrarily assigning shared electrons to specific atoms.
What happens to the oxidation number during oxidation and reduction?
• Oxidation: Oxidation number increases.
• Reduction: Oxidation number decreases.
What steps are used to solve stoichiometry problems for reactions in solution?
- Identify species and reactions.
- Write balanced equations.
- Calculate moles of reactants and products.
- Determine limiting reagent.
- Convert moles to grams or other units.
