Topic 3 - Redox

What is oxidation

Loss of electrons

What is reduction

Gain of electrons

What happens to an oxidising agent

It is reduced

What happens to reducing agents

They are oxidised

How do electron numbers change when electrons are lost

they increase

what are redox reactions between

metals and acid

what is the general equation for a metal reacting with an acid

metal + acid → salt + hydrogen

what is the oxidation state of uncombined elements

0

What is the sum of the oxidation numbers equal to in a molecular ion

the charge

what is the oxidation state of oxygen

-2

what two other oxidation states can oxygen have and when

in peroxides it’s -1 and in OF2 it’s +2

what is the usual oxidation state of hydrogen

+1

when is hydrogen not in usual oxidation state

when it forms a metal hydride (-1)

what is ALWAYS the oxidation state of fluorine

-1

What are ions ending in “ate” made from

oxygen and another element

how do we show that an element has variable oxidation numbers

roman numerals

what do half equations show

electron transfer

what needs to be equal before you can combine half equations

the number of electrons

what is disproportionation

when an element is simultaneously oxidised and reduced