Electrochemistry

In a redox reaction, the species that loses electrons

• is called the cathode

• is oxidized

• gains mass at the electrode

• decreases in oxidation number

Tags

NGSS.HS-PS1-2

As an element is oxidized, its oxidation number

• decreases as electrons are lost

• increases as electrons are lost

• decreases as electrons are gained

• increases as electrons are gained

Tags

NGSS.HS-PS1-2

Mg + PbCl₂ → MgCl₂ + Pb

Which statement correctly describes the oxidation and reduction that occur?

• Mg is oxidized and Pb⁺² is reduced

• Mg is oxidized and Cl^- is reduced

• Mg is reduced and Cl^- is oxidized

• Mg is reduced and Pb⁺² is oxidized

Tags

NGSS.HS-PS1-2

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.

Tags

NGSS.HS-PS1-2

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.

Table shows information about three chemical cells.

What is the possible potential difference of the chemical cell when metal Z is paired with W ?

• 0.3 V

• 1.2 V

• 1.5 V

• 2.1 V

Tags

NGSS.HS-PS1-1

NGSS.HS-PS3-5

Diagram shows the electrolysis of concentrated copper(II) chloride solution using carbon as electrodes.

Which of the followings is the correct half equations represents the reactions at the anode?

• 4OH^- → 2H₂O + O₂ + 4e

• 2Cl^- → Cl₂ + 2e

• Cu → Cu²⁺ + 2e

• Cu²⁺ + 2e → Cu

Tags

NGSS.HS-PS1-2

What occurs to the mass of copper electrode in the following reaction?

Zn/Zn²⁺ // Cu²⁺/Cu

• increases

• decreases

• remains the same

Tags

NGSS.HS-PS1-7

What reaction occurs at the anode?

Ag⁺/Ag = 0.80V

Ni²⁺/Ni = -0.25V

• Ag⁺ + e^- →Ag

• Ag → Ag⁺ + e^-

• Ni²⁺ + 2e^- → Ni

• Ni → Ni²⁺ + 2e^-

Tags

NGSS.HS-PS1-2

What would be the theoretical cell potential of the previous electrochemical cell?

Ag⁺/Ag = 0.80V

Ni²⁺/Ni = -0.25V

• 1.05V

• -1.05V

• 0.55V

• -0.55V