Question
Which of the following hydroxide is acidic ?
A.
$$Al{\left( {OH} \right)_3}$$
B.
$$Ca{\left( {OH} \right)_3}$$
C.
$$Tl{\left( {OH} \right)_3}$$
D.
$$B{\left( {OH} \right)_3}$$
Answer :
$$B{\left( {OH} \right)_3}$$
Solution :
$$B{\left( {OH} \right)_3}$$ is acid because it can take $$O{H^ - }{\kern 1pt} ions.$$
$${H_3}B{O_3}\,{\text{or}}\,B{\left( {OH} \right)_3} + O{H^ - } \to B\left( {OH} \right)_4^ - $$