# Math Help - Determining pH

1. ## Determining pH

After titrating sodium hydroxide with hydrofluoric acid, a chemist determined that the reaction had formed an aqueous solution of 0.020mol/L sodium fluoride. Determine the pH of the solution.

Thank you

2. First we have to assume that all of the hydrofluoric acid is reacting (which is a reasonable assumption). From the stiochemistry of the reaction you know that one moles of hydrofluoric acid acid reacts to give a mole sodium fluoride and a mole of H+ ions.

so the ph should just be $- \log (0.02)$

but then i havent accounted for the affect of the following eqaulbirum $H^{+} + OH^{-} \Leftrightarrow H_{2} O$
in which case you would need to know the water dissociation constant for the given conditions.