What is a buffer and what do you need to make one?

A buffer is a solution which resists changes in pH when alkaline or acidic solution is added to it.

Buffers are created based on the equilibrium of a proton donor/ acceptor and the conjugate base/ acid. For example, a weak acid and it's salt can act as a buffer. The weak acid hardly dissociates whilst the salt fully dissociates to give a large concentration of ions. The weak acid and its dissociated ion then exist in equilibrium to resist changes in pH made by adding or withdrawing protons. 

FB

Related Chemistry A Level answers

All answers ▸

How does the reactivity change down Group 1 elements, and why?


Explain the effect of increasing concentraion of O2 on the equilibrium position of this gas phase reaction and what you might see given that Nitrogen Oxide and Nitrogen Dioxide appear colourless and brown respectively. NO + 0.5O2 ----> NO2


How would you determine the pH of a solution?


Explain the decrease in reactivity of Group 2 elements as you go down the periodic table