Question

When \[BC{l_3}\] reacts with excess of \[{H_2}O\] in the presence of NaOH. Then the formed product(s) is/are:
(this question has multiple correct options)
A.\[Na[B{(OH)_4}]\]
B.NaCl
C.HOCl
D.HCl

Answer 1

Hint: \[BC{l_3}\] or boron trichloride is a colourless gas which generally exudes a pungent odour. The structure of boron trichloride can be understood as follows: born is the central atom in this compound. It is bonded by 3 chlorine atoms by 3 sigma bonds. Also, there are no lone pairs of electrons present on the central atom. From this we can determine that there are 6 electrons present in the valence shell of the boron atom. Thus, boron trichloride acts like a Lewis base.

Complete step by step answer:
Before we move forward with the solution of the given question, let us first understand some important basic concepts.
The reactivity of the \[ - OH\] group is higher than -Cl group. Hence, when water and NaOH react with boron trichloride, the -OH substituents from these compounds substitute the \[ - Cl\] group and form the ion \[{[B{(OH)_4}]^ - }\] . This ion has a unit negative charge; hence it attaches itself to the unit positive sodium ion. This results in the formation of \[Na[B{(OH)_4}]\] . Also, the chlorine atoms which were released from \[BC{l_3}\] attach to the remaining sodium ion to form NaCl. Hence, the chemical equation for this reaction can be given as:
 \[2BC{l_3} + 3{H_2}O + 2NaOH \to Na[B{(OH)_4}] + NaCl\]
Hence, when \[BC{l_3}\] reacts with excess of \[{H_2}O\] in the presence of NaOH, then the formed products are \[Na[B{(OH)_4}]\] and NaCl

Hence, Options A and B are the correct options.

 Note:
\[BC{l_3}\] gas is very reactive and can be corrosive when brought in contact with metals. It is also toxic for tissue cells. When a human comes in contact with this gas, it usually causes irritation in the eyes as well as the mucous membranes.