Which one among the following statements is correct about a solution of borax in water ?

Options

A. it is acidic because it contains `H_3 BO_3 and NaOH`
B. it dissociates into `NaBO_2 and B_2O_3`
C. it is neutral because it contains `NaOH and H_3 BO_3`
D. it is alkaline because it contains `NaOH and H_3 BO_3`

Answer

D

Explanation

Chemical formula of borax is `Na_2[B_4O_5(OH)_4].8H_2O`. It is a salt of strong base which is NaOH and a weak acid, that is `H_3BO_3`. Thus, borax is basic in nature because a strong base added in weak acid. Hence, resultant aqueous solution of borax will be basic in nature.
The solution of borax in water is
`Na_2B_4O_7+7H_2O rarr 2NaOH+4H_3BO_3`