Question
An aqueous solution of boric acid is found to be weakly acidic in nature because
A.
it is a protic acid which donates protons in aqueous solution.
B.
it is a Lewis acid which abstracts $$O{H^ - }$$ from water and leaves $${H^ + }$$ to make the solution acidic.
C.
it gives metaboric acid when dissolved in water.
D.
it is prepared by reaction of borax with sulphuric acid hence it behaves as an acid.
Answer :
it is a Lewis acid which abstracts $$O{H^ - }$$ from water and leaves $${H^ + }$$ to make the solution acidic.
Solution :
It reacts with water to abstract $$O{H^ - }$$ ions and releases $${H_3}{O^ + }$$ ions making it acidic.
$${H_3}B{O_3} + 2{H_2}O \to {H_3}{O^ + } + $$ $${\left[ {B{{\left( {OH} \right)}_4}} \right]^ - }$$