Question

Why is it possible to have a concentrated weak acid?

Answer 1

Because `"concentration"` refers to the amount of solute present in a given volume of `"solution.........."`

Explanation:

`"Acetic acid"`, `"H"_3"CCO"_2"H"`, CERTAINLY behaves as a weak acid in water, i.e. the following equilibrium lies to the left as we face the page:

`"H"_3"CCO"_2"H" +"H"_2"O"rightleftharpoons"H"_3"CCO"_2^(-) +"H"_3"O"^+`

This equilibrium may be carefully measured, and......................

`K_a=(["H"_3"CCO"_2^(-)]["H"_3"O"^+])/(["H"_3"CCO"_2"H"])=10^(-4.76)`

Glacial acetic acid (i.e. very pure acetic acid), has a concentration of `15.5*mol*L^-1`; of course the description of acidity requires dissolution in water.............