Chemistry - Chemical reactions (REDOX, PART 3)

Oxidation

a gain of oxgyen

Reducation

A loss of oxgyen

Redox reaction

Reaction involoving oxidation and reduction

Oxidation (in terms of electrons)

Loss of electrons

Reduction (in terms of electrons)

Gain of electrons

What is a anagram to remember oxidation and reduction?

OIL RIG

What does the oxidation number tell you?

How many electrons each atom of an element has lost/gained in forming a compound

Rules for oxidation number

• Each atom in a formula has an oxidation number

• Oxidation number is given as a Roman numeral

• Oxidation of an uncombined element is 0

Oxidation number of a simple ion is the same as its charge

• Oxidation numbers in the formula of a compound add up to zero

If oxidation numbers change during a reaction it is….

a redox reaction

A rise in oxidation numbers mean…

oxidation has occured

A fall in oxidation number means…

reduction has occured

Oxidising agent

a substance that oxidises another substance and is itself reduced

Reducing agent

a suubstance that reduces another substance and is itself oxdised

Why are some substances used as oxidising and reducing agent in the lab?

Some substances have a strong drive to gain or lose electrons. Some of these substances also show a colour change when they react which is helpful

What is an example of an oxidising agent in the lab?

Potassium manganate (VII)

Why is Potassium manganate (VII) used in the lab?

Has a strong drive to reduce its oxidiation number to (II), by taking electrons from another substance, acts as a power ful oxidising agent and is itself reduced with a colour change. Can test

How can is Potassium manganate (VII) used?

TO test for a reducing agent, will go from purple (magnesium (VII) ion) to colourless (Magnesium (II) ion)`

What is an example of a reducing agent in the lab?

Potassium iodine

Why is Potassium iodine used in the lab?

Used to test for the precense of an oxidising agent, potassium iodine goes from colourless to red brown when it is oxidised.