buffers Flashcards
what is a buffer solution?
maintains pH when a small amount of acid/ alkali is added
what pH do acidic buffers maintain?
below 7
what pH do basic buffers maintain?
above 7
how do u make an acidic buffer?
weak acid and it’s salt (conjugate base)
how do u make a basic buffer?
weak base and it’s salt (conjugate acid)
what’s the 2nd way to make an acidic buffer?
by partially neutralising the weak acid
describe how a buffer works when acid is added?
H+ reacts with the acid ion shifting the equilibrium to the left
what’s the effect when a base is added?
lowers H+ concerntration so base dissociates to replace them. Equilibrium shifts to the right
what are examples of everyday buffers ?
skin and hair products- have to match pH of skin and hair so it doesn’t cause any damage
describe the buffer system in blood?
blood has to have a pH between 7.35-7.45
buffer system is made from carbonic acid in equilibrium with hydrogen carbonate
what happens when blood pH becomes more acidic?
-there will be a higher H+ concerntration
- the resivour of HCO3- (conj base) will react with extra H+ ions shifting the equilibrium to the left
what happens when the blood pH becomes more alkali?
-H+ concerntration drops
- large resivour of H2CO3 (weak acid) dissociates more and will move the equilibrium to the right replacing the H+ ions which have been taken out
what happens if acidic materials are released into the blood?
H2CO3 dissociates to form H+ and CO2
which is taken to the lungs and breathed out