In: Chemistry
Hyrdrofluoric acid (Ka = 7.2 x 10-4), is used in a
wide range of commercial processes. HF is used for glass etching
and the synthesis of pharmaceutical drugs and compounds such as
teflon. One issue with HF is its corrosive nature, "Aqueous
hydrofluoric acid is a contact-poison with the potential for deep,
initially painless burns and ensuing tissue death." (from Wikepedia
page on hydrofluoric acid).
The flouride ion is often used in dental procedures, as the F- can
react with tooth enamel to form highly stable mineral
fluorohydroxyapatite (which is less likely to break down in the
mouth than "normal" enamel). One common form of F-
delivery is fluoride varnish, which has a F-
concentration of around 1.778 M.
Given what you know of the acid base chemistry of HF, what is the
concentration of HF in an aqueous solution with a pH of 5.85?