Question

Which of the following is the strongest base?
A.$Be{(OH)_2}$
B.$Mg{(OH)_2}$
C.$Al{(OH)_3}$
D.$Si{(OH)_4}$

Answer 1

Hint:Identify which base has the most tendency to remove a proton or that can dissociate well in water. If an atom is larger in size then it has a greater tendency to lose electrons thus will behave as a stronger base.

Complete answer:
First let us see what a base is. An ionic compound is a compound containing a positive metal ion and a non-metal anion. The ionic compounds which produce a hydroxide anion upon ionization in water that is by dissolving in water are known as bases such as sodium hydroxide and potassium hydroxide.
There are many types of bases based upon the nature of disassociation. They are strong base, weak base, superbase, neutral base and solid base.
Strong bases are the compounds that can remove a proton from weak acid or they can completely dissociate into its ions when dissolved in water.
Magnesium, silicon and aluminum belong to the same period. As we go along a period the size of the atom decreases and hence the tendency to lose electrons also decreases. Now magnesium and beryllium belong to the same group. As we move from beryllium to magnesium, the size of the atom increases so the tendency to lose electrons increases.
Based upon these factors we can say that $Mg{(OH)_2}$ is the strongest base among the given choices.

So, option B is the correct answer.

Note:
Ortho-diethynylbenzene dianion is considered to be the strongest base. It is stronger than lithium monoxide anion and has the strongest proton affinity. Drain cleaner has the most pH value equal to 14. It is mostly composed of sodium hydroxide.