Which of the following are correct for boron compounds met in the borate test?

ATurmeric paper dipped in acidified borate solution and dried turns red-brown
B $B (OH) X_{3}$ is a strong tribasic Bronsted acid
CTrimethyl borate, formed with methanol and conc. $H X_{2} SO X_{4}$ , burns with a green-edged flame
D $B (OH) X_{3}$ acts as a Lewis acid by accepting $OH X^{-}$

Answer: A, C, D

Boron in

B (OH) X_{3}

has an empty

p

orbital and accepts

OH X^{-}

to form

[B (OH) X_{4}] X^{-}

. The ester

B (OCH X_{3}) X_{3}

is volatile and burns with a green-edged flame. Boric acid colours turmeric paper red-brown on drying. It is not a strong or tribasic acid; it is a weak monobasic Lewis acid.

Practice Qualitative Analysis: Anions More on Independent group: sulphate, phosphate, borate

Previous questionNext question

Which of the following are correct for boron compounds met in the borate test?

Answer: A, C, D

More questions on Independent group: sulphate, phosphate, borate