Learn: Chemistry - Oxidation and Reduction

What is the difference between compounds ending in -ate and. -ite?

-ate = more oxygen

-ite = less oxygen

Lewis Acid

Electron pair acceptor

Lewis base

Electron pair donor

Oxidation

Loss of electrons

Oxidation exmples

Combustion and rusting

Reduction

Gain of electrons

Reduction example

Electroplating and reducing iron ore

Oxidation state of pure elements

0

Which element has a negative oxidation state in covalent compounds?

The more electronegative element

When is Hydrogen's oxidation state positive and when is it negative?

Negative with metals, positive with nonmetals

What is a redox reaction?

A reaction where the oxidation number of any element changes from reactants to products

Oxidation and reduction always come in _____

pairs

Most double-replacement reactions are...

NOT redox reactions

Most reactions involving uncombined elements...

ARE redox reactions

How can you tell if a reaction is spontaneous?

A metal will react with the ion compound of a metal below it on Table J

Which metal is oxidized in a spontaneous redox reaction?

The more active metal (higher on Table J)

Which metal is reduced in a spontaneous redox reaction?

The less active metal (lower on Table J)

What is an oxidizing agent?

The species in a reaction that is reduced

What is a reducing agent?

The species in a reaction that is oxidized

What is a half reaction?

A reaction that shows either the oxidation o reduction portion of a redox reaction and the electrons gained/lost

What is an electrolytic cell?

Requires energy to force a non-spontaneous redox reaction to occur

What is a voltaic/galvanic cell?

Utilizes spontaneous redox reactions to produce electrical energy

What is an anode? (voltaic cell)

The electrode where oxidation takes place. The negative terminal on a battery

What is a cathode? (voltaic cell)

The electrode where reduction takes place. The positive terminal on a battery

What is a salt bridge? (voltaic cell)

Provides a medium for the ions to travel back and forth

How do electrons flow in a voltaic cell?

Away from the anode and closer to the cathode

What is the shorthand redox reaction equation? (Use Zn and Cu as an example)

Zn | Zn+2 || Cu+2 | Cu

Which sides do the anode and cathode go on in a shorthand redox equation?

Anode on the left, cathode on the right

What is the cell potential equation?

E(cell) = E(red.) - E(ox.)

Do you change the voltage when you multiply a half reaction by an integer?

No!

What does it mean if E(cell) is positive?

Spontaneous redox, voltaic cell, energy produced

What does it mean if E(cell) is negative?

Non-spontaneous redox, electrolytic cell, energy required

What does it mean if E(cell) = 0?

Equilibrium

What is an anode? (electrolytic cell)

Positive terminal, oxidation

What is a cathode? (electrolytic cell)

Negative terminal, reduction

What are the 3 purposes for electrolytic cells?

Electrolysis of a fused salt, electrolysis of water, electroplating

In electroplating, which object is the cathode?

The object getting plated