[maccha]

My textbook says that SiO2 is weakly acidic and forms silicate ions upon reacting with OH-. I think I must have learned a very narrow definition of an acid in highschool- basically, I learned it was a substance that donated H+. I understand that non-metal oxides will react with water to produce acidic substances, but does that makes them acidic themselves? How does SiO2 react with OH- to form silicate? I can't picture the reaction.

[nj_bartel]

http://facultyfp.salisbury.edu/dfrieck/htdocs/212/rev/acidbase/lewis.htm

[Borek]

No need for Lewis theory here:

http://www.chembuddy.com/?left=pH-calculation&right=bronsted-lowry-theory

[FeLiXe]

and the reaction is something like:

SiO2 + 2 OH- -> SiO4H2^2-