Electrochemistry Flashcards

Flashcards about Redox Reactions and Electrochemistry

What type of reaction involves the transfer of electrons?

Oxidation-reduction (redox) reaction

In a redox reaction, what happens to the oxidation numbers of the atoms involved?

One oxidation number goes up (oxidation) and one oxidation number goes down (reduction).

Which particle is gained or lost during a redox reaction?

Electrons

What happens to the number of neutrons in the nucleus of a Ca atom as it undergoes oxidation to Ca2+?

Remains the same

What is the oxidation number of an element that is not in a compound?

Zero (0)

What are the oxidation numbers of Group 1 and Group 2 metals, respectively?

1+ and 2+

What is the oxidation number of Fluorine?

Fluorine is always 1-

What is the oxidation number of Oxygen?

Oxygen is always 2- except when combined with F (OF2) or the peroxide ion (O2 2-)

What process is defined as the gain of electrons?

Reduction

In reduction, what happens to the oxidation number?

Goes down (reduces)

In a reduction half-reaction, on which side are electrons written?

Left Side

What process is defined as the loss of electrons?

Oxidation

In oxidation, what happens to the oxidation number?

Goes up (increases)

In an oxidation half-reaction, on which side are electrons written?

Right Side

What does LEO stand for in LEO growls GER?

Losing Electrons Oxidation

What does GER stand for in LEO growls GER?

Gaining Electrons Reduction

In the reaction Mg(s) + 2H+(aq) + 2Cl–(aq) -> Mg2+(aq) + 2Cl–(aq) + H2(g), which species undergoes oxidation?

Mg(s)

In the equation C(s) + H2O(g) -> CO(g) + H2 (g), which species undergoes reduction?

H+

In any redox reaction, what occurs to the substance that undergoes reduction?

Gain electrons and have a decrease in oxidation number

In the equation 2 Al + 3 Cu2+ -> 2 Al3+ + 3Cu, what is the reduction half-reaction?

Cu 2+ + 2e – -> Cu

What do changes in oxidation numbers indicate?

Oxidation and reduction have occurred

What is the sum of the oxidation numbers of all the atoms in a compound?

Zero

What is the sum of the oxidation numbers of all the atoms in a polyatomic ion equal to?

The charge of the ion

What is the oxidation number of chromium in K2Cr2O7?

+6

In which substance does chlorine have an oxidation number of +1?

HClO

During redox, what two processes always happen together?

Oxidation and Reduction

In a redox reaction, what is the relationship between the number of electrons lost and gained?

The number of electrons lost is equal to the number of electrons gained.

According to Reference Table J, what will a more active metal do?

Replace an ion below it on Table J.

According to Reference Table J, which of these metals will react most readily with 1.0 M HCl to produce H2(g)?

K

What type of energy conversion occurs in a voltaic cell?

Chemical energy to electrical energy

In an electrochemical cell, where do oxidation and reduction occur?

Oxidation occurs at the anode and reduction occurs at the cathode.

What type of energy is required for an electrolytic cell to produce a chemical change?

Electrical energy

What is fluorine always

1-

What is oxygen always?

always 2- except when combined with F (OF₂) or the peroxide ion (O₂^2-)

What do nonmetals do in reduction?

 gain electrons to form ions