Contextualising the topic
Why buffer solutions are important, eg in keeping us alive. Blood pH 7.4. Cells use oxygen, give off CO2, dissolves in blood (CO2 dissolves in aqueous solutions forming carbonic acid). Note equation here? Blood pH could drop as a result which would be dangerous. Carbonic acid and hydrogen carbonate ions keep blood plasma at pH 7.4.
Food preservatives.
http://pubs.rsc.org/en/content/articlelanding/rp/2000/a9rp90016k#!divAbstract