EQHILIBRIA AND REDOX REACTION PART 2

Increasing the temperature adds heat

the equilibrium shifts in the endothermic direction to absorb heat

decreasing the temperature removes heat

the equilibrium shifts in the exothermic direction to replace heat

if you change the temperature and cause more product to form

K_c value increases

if you change the temperature and cause less product to form

K_c value decreases

changing the concentration…

does not affect the K_c value

adding a catalyst

has no effect of the equilibrium position or K_c value because it increases the rate of both forwards and backwards reactions by the same amount so equilibrium will only be reached faster

how do catalysts increase the rate of reaction?

catalyst provide the surface for a reaction therefore increasing the surface area which increases the number of available active sites which increases the frequency of successful collisions

oxidation

loss of electrons

reduction

gain of electrons

redox

reduction and oxidation occurring at the same time

oxidising agent

accepts electrons and gets reduced

reducing agents

donates electrons and gets oxidised

oxidation state/ number

total number of electrons an element has donated or accepted

elements with an oxidation state of 0

• uncombine elements

• elements bonded to identical atoms

atoms in compounds/ compound ions

have their own oxidation states which sum up to make the compounds overall oxidation state

within compound ions

the most electronegative elements has a negative oxidation state while others have positive ones

oxygen normally has an oxidation state of 2-

HOWEVER when in a PEROXIDE, oxygen has an oxidation number of -1

hydrogen usually has +1 oxidation state

when hydrogen is bonded to a metal like Li/Na etc its oxidation state is -1

ionic half equations show oxidation or reduction

electrons are shown in a half equation so the charges balance