Why do all acid solutions have a small amount of OH present in the acid solution?

An acid solution is the acid in some water basically. Since the acid and the water will dissociate you will have H+ and OH- instead of H20.

For example a solution of HCl would contain

H+ and Cl- from the acid and H+ and OH- from the water

As mentioned, acid SOLUTION.

Solution means it contains water, H2O. If molten state, means there is no water ( ok, we are not going to talk about molten)

we know that acid will dissociate in the water to form H+ or H3O+. Strong acid(dissociate completely), weak acid(dissociate partially)

BUT,dont forget that in the solution, we still have water, H2O.

H2O also will undergo dissociation to form H+ and OH-.

Since the Kw is very small which is 1x10^7. small amount of OH- will be produced.

Its in the name acid solution.

solution refers to water being present.

water is H2O which is H+ and OH-.

So as long as its a solution, OH- will be present.