Ch 15 (Electrochemistry)

What is reduction?

• It is the gain of electrons.

• It is the loss of electrons.

• It is the creation of electrons.

• It is the destruction of electrons.

Answer explanation

Reduction refers to the gain of electrons in a chemical reaction. This process decreases the oxidation state of an atom, making 'It is the gain of electrons' the correct choice.

Tags

NGSS.HS-PS1-2

What is oxidation?

• It is the gain of electrons.

• It is the loss of electrons.

• It is the creation of electrons.

• It is the destruction of electrons.

Answer explanation

Oxidation is defined as the loss of electrons from an atom or molecule. This process often occurs in chemical reactions, leading to an increase in oxidation state, making 'It is the loss of electrons' the correct choice.

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-1

What is a reducing agent?

• It is the species that gets reduced -- gains electrons.

• It is the species that gets oxidized -- loses electrons.

• It is the species that creates electrons.

• It is the species that destroys electrons.

Answer explanation

A reducing agent is the species that gets oxidized, meaning it loses electrons. This process allows another species to gain those electrons and be reduced, which is the essence of redox reactions.

Tags

NGSS.HS-PS1-2

What is an oxidizing agent?

• It is the species that gets reduced -- gains electrons.

• It is the species that gets oxidized -- loses electrons.

• It is the species that creates electrons.

• It is the species that loses electrons.

Answer explanation

An oxidizing agent is the species that gets reduced, meaning it gains electrons during a chemical reaction. This is why the correct answer is that it is the species that gets reduced -- gains electrons.

Tags

NGSS.HS-PS1-2

What is a galvanic (voltaic) cell?

• It is a cell that destroys electrons on one side and creates electrons on the other side.

• It is a cell that contains only one metal bar and one aqueous ion solution.

• It is a type of battery that drives a redox reaction when electricity is applied.

• It is a type of battery that generates an electrical current from redox reactions.

Answer explanation

A galvanic (voltaic) cell generates electrical current through redox reactions, converting chemical energy into electrical energy, making the correct choice the one that describes this process accurately.

What is a standard half-cell?

• It is one cell that comprises half of a whole battery.

• It is a cell containing only a metal bar with no aqueous ion solution.

• It is a cell containing only an aqueous ion solution and no metal bar.

• It is a cell that generates half of a volt of electricity.

Answer explanation

A standard half-cell refers to one part of a galvanic cell, which is half of a complete electrochemical cell. It typically includes an electrode and an electrolyte, making the first answer choice correct.

What is a half-reaction?

• It is a reaction at equilibrium where half of the substances are reactants and half of the substances are products.

• It is the reaction that occurs when the switch of a galvanic cell is open.

• It shows EITHER the reduction component or the oxidation component of a redox reaction.

• It shows BOTH the reduction and oxidation components of a redox reaction.

Answer explanation

A half-reaction represents either the reduction or oxidation part of a redox reaction, allowing us to analyze the electron transfer process separately. This is why the correct choice is that it shows EITHER the reduction or oxidation component.

What is an anode?

• It is the electrode where oxidation takes place.

• It is the electrode where reduction takes place.

• It is an aqueous solution containing an electrode.

• It is the salt bridge that connects half-cells.

Answer explanation

An anode is defined as the electrode where oxidation occurs. During oxidation, electrons are released, making the anode crucial in electrochemical reactions, distinguishing it from the cathode where reduction takes place.

What is a cathode?

• It is the electrode where oxidation takes place.

• It is the electrode where reduction takes place.

• It is an aqueous solution containing an electrode.

• It is the salt bridge that connects half-cells.

Answer explanation

A cathode is defined as the electrode where reduction occurs, meaning it gains electrons during a chemical reaction. This distinguishes it from the anode, where oxidation takes place.

Given their standard reduction potentials, which of the species is going to be oxidized?

Cu²⁺/Cu = 0.34V

Zn²⁺/Zn = -0.76V

• Cu

• Zn

• CuSO4

• ZnSO4

Answer explanation

Zn has a lower standard reduction potential (-0.76V) compared to Cu (0.34V), indicating that Zn is more likely to be oxidized. Therefore, Zn will lose electrons and be oxidized in the reaction.

Tags

NGSS.HS-PS1-2