Topic 4 REDOX Reactions

Question 1

What is a REDOX reaction?

Answer 1

Reactions where one or more electrons are transferred

REDOX stands for oxidation-reduction reactions, which are crucial in various chemical processes.

Question 2

Define oxidation in terms of oxidation number.

Answer 2

Increase in oxidation number

Oxidation involves the loss of electrons, leading to an increase in oxidation state.

Question 3

Define reduction in terms of oxidation number.

Answer 3

Decrease in oxidation number

Reduction involves the gain of electrons, resulting in a decrease in oxidation state.

Question 4

What is an oxidizing agent?

Answer 4

Chemical species that allows reduction to occur, itself gets oxidized

Oxidizing agents gain electrons during a reaction.

Question 5

What is a reducing agent?

Answer 5

Chemical species that allows oxidation to occur, itself gets reduced

Reducing agents lose electrons during a reaction.

Question 6

What does the acronym OILRIG stand for?

Answer 6

Oxidation Is Loss, Reduction Is Gain

This acronym helps remember the definitions of oxidation and reduction.

Question 7

What are the two main types of REDOX reactions?

Answer 7

Oxidation and reduction

Each REDOX reaction involves an oxidation process and a corresponding reduction process.

Question 8

What is the purpose of oxidation states in REDOX reactions?

Answer 8

To keep track of electrons

Oxidation states help identify how many electrons are lost or gained by each atom in a reaction.

Question 9

What is a precipitate?

Answer 9

An insoluble substance that forms when two solutions are mixed

The solid product that separates from the solution is called a precipitate.

Question 10

What are strong electrolytes?

Answer 10

Electrolytes that are completely ionized when dissolved in water

Strong electrolytes conduct electricity well due to the presence of ions.

Question 11

What are weak electrolytes?

Answer 11

Electrolytes that show a small degree of ionization

Weak electrolytes produce relatively few ions in solution.

Question 12

What does the term ‘stoichiometry’ refer to in chemical reactions?

Answer 12

The calculation of reactants and products in chemical reactions

Stoichiometry is vital for predicting the outcomes of reactions.

Question 13

What is the first step in balancing a REDOX reaction using the half-reaction method?

Answer 13

Write the two half-reactions that identify oxidation and reduction processes

This method helps simplify the balancing of complex reactions.

Question 14

What is the role of water molecules when balancing half-reactions?

Answer 14

To balance oxygen atoms

Water is added to one side of the half-reaction to account for oxygen atoms.

Question 15

What is the function of hydrogen ions in balancing half-reactions?

Answer 15

To balance hydrogen atoms

Hydrogen ions are added when balancing reactions that involve hydrogen.

Question 16

Fill in the blank: Water has the ability to ____________ many different substances.

Answer 16

DISSOLVE

Water’s solvent properties allow it to dissolve a wide range of substances.

Question 17

Fill in the blank: In a chemical solution, the substance that is dissolved is called the ________.

Answer 17

SOLUTE

The solute is the component of a solution that is present in a lesser amount.

Question 18

Fill in the blank: In a chemical solution, the substance in which the solute is dissolved is called the ________.

Answer 18

SOLVENT

The solvent is usually the component present in a greater amount.

Question 19

What is the significance of balancing oxidation-reduction reactions?

Answer 19

To ensure that the number of electrons lost equals the number gained

Balancing ensures conservation of mass and charge in the reaction.

Question 20

True or False: All chemical reactions involve changes in oxidation states.

Answer 20

False

Only oxidation-reduction reactions involve changes in oxidation states.

Question 21

What is the importance of studying Arrhenius’s work on conductivity?

Answer 21

Understanding that conductivity is due to the presence of ions

Arrhenius’s studies laid the foundation for the modern understanding of electrolytes.

Question 22

What must be done if a reaction occurs in a basic solution when balancing?

Answer 22

Change H+ using H2O molecules and balance with OH-

This ensures that the reaction is balanced for both mass and charge.