Question
Metals form basic hydroxides. Which of the following metal hydroxide is the least basic?
A.
$$Mg{\left( {OH} \right)_2}$$
B.
$$Ca{\left( {OH} \right)_2}$$
C.
$$Sr{\left( {OH} \right)_2}$$
D.
$$Ba{\left( {OH} \right)_2}$$
Answer :
$$Mg{\left( {OH} \right)_2}$$
Solution :
The basic character of metal hydroxides increases down the group from $$Mg{\left( {OH} \right)_2}$$ to $$Ba{\left( {OH} \right)_2}$$ due to increase in size, ionization enthalpy decreases and the $$M - O$$ bond becomes weaker.