Redox Processes - Topic 9

What is oxidation?

The gain of oxygen, loss of electrons, or increase in oxidation state

What is reduction?

The loss of hydrogen, gain of electrons, or decrease in oxidation state

What is an oxidation agent?

A species that is reduced, and causes another species to be oxidized

What is a reduction agent?

A species that is oxidized, and causes another species to be reduced

Which elements have the most variable oxidation states?

The transition metals and most main-group non-metal (excepting fluorine)

What is the activity series?

A scale that ranks metals according to the ease with which they undergo oxidation

What is the Winkler method?

A method that measures the dissolved oxygen content in a sample of water. It can be used to measure biochemical oxygen demand (BOD) which is a measure of pollution in water

What is a voltaic cell?

A cell that converts energy from spontaneous exothermic chemical processes to electrical energy

What is another name for voltaic cells?

Galvanic cells

Where does oxidation and reduction occur in a voltaic cell?

Oxidation occurs that the anode and reduction occurs at the cathode

What is the anode in a voltaic cell?

The negative electrode

What is the cathode in a voltaic cell?

The positive electrode

What is an electrolytic cell?

A cell that converts electrical energy into chemical energy by means of non-spontaneous processes

Where do oxidation and reduction occur in an electrolytic cell?

Oxidation occurs at the anode and reduction occurs at the cathode

What is a cathode in an electrolytic cell?

The negative electrode

What is an anode in an electrolytic cell?

The positive electrode

What is the molecular formula for graphite?

C

What is the chemical formula of alumina?

Al2O3

What is the function of a salt bridge in a voltaic cell?

The salt bridge provides the cations for the cathode and the anions for the anode, as well as it conducts the electron flow to complete the circuit