Question

The pair of amphoteric hydroxides is:

• A. $Al{\left(OH\right)}_3,LiOH$
• B. $Be{\left(OH\right)}_3,Mg{\left(OH\right)}_2$
• C. $B{\left(OH\right)}_3,Be{\left(OH\right)}_2$
• D. $Be{\left(OH\right)}_2,Zn{\left(OH\right)}_2$

Answer 1

The correct option is D $Be{\left(OH\right)}_2,Zn{\left(OH\right)}_2$

• In chemistry, an amphoteric compound is a molecule or ion that can react both as an acid and as a base. Many metals (such as copper, zinc, tin, lead, aluminium, and beryllium) form amphoteric oxides or hydroxides. $A{l}_2{O}_3$ is an example of an amphoteric oxide.
  
• Aluminium hydroxide-$\left(Al\right(OH{)}_3)$ is amphoteric in nature, i.e., it has both basic and acidic properties.
  
• Like the hydroxides of other metals, such as lead, aluminium, beryllium, tin and chromium, zinc hydroxide (and zinc oxide), is amphoteric. Thus it will dissolve readily in a dilute solution of a strong acid, such as HCl, and also in a solution of an alkali such as sodium hydroxide.
  
• Beryllium hydroxide, $Be(OH{)}_2$, is an amphoteric hydroxide, dissolving in both acids and alkalis.
  
• Hence option D is a correct answer.