Question

What happens when a borax solution is acidified? Write a balanced chemical equation for the reaction.

Answer 1

We know that borax is a compound made up of an element called boron combined with oxygen and soda. The borax formula is also known as sodium borate formula, sodium tetraborate formula, or disodium tetraborate formula. Borax is a Boron compound that is soft and colourless and may be dissolved in water and acids are ionic compounds that, when dissolved in water, produce positive hydrogen ions.

Complete answer:
We know that borax has the chemical formula ${\text{N}}{{\text{a}}_{\text{2}}}{{\text{B}}_{\text{4}}}{{\text{O}}_{\text{7}}}$. Acidification of Borax literally means the reaction of borax solution with an acid. As said before, acids are ionic compounds that, when dissolved in water, produce positive hydrogen ions and the borax will be reacting with these hydrogen ions.
So, what happens when a borax solution is acidified is that a weak monobasic Lewis acid of boron, called Boric acid, which has the chemical formula ${{\text{H}}_{\text{3}}}{\text{B}}{{\text{O}}_{\text{3}}}$ is formed and a corresponding sodium salt of the acid used is produced.
A balanced chemical equation for the reaction can be written as follows,
${\text{N}}{{\text{a}}_{\text{2}}}{{\text{B}}_{\text{4}}}{{\text{O}}_{\text{7}}}{\text{ + 2HCl + 5}}{{\text{H}}_{\text{2}}}{\text{O}} \to {\text{2NaCl + 4}}{{\text{H}}_{\text{3}}}{\text{B}}{{\text{O}}_{\text{3}}}$
Here, Borax in the presence of water (borax solution) reacts with an acid ( Hydrochloric acid) to give Boric acid and sodium chloride.

Note:
We should know that although boric acid is weak monobasic Lewis acid of boron, in some chemical reactions, it can also act as a tribasic acid. It can also be known by the names hydrogen borate, boracic acid and orthoboric acid. Its IUPAC name is tetrahydroxydiboron. If boric acid occurs in nature, it is usually known by the name sassolite. At room temperature, it is found in crystalline solid form. It is also a constituent of many naturally occurring minerals.