Boron trifluoride (BF3)
- It acts as a catalyst in organic reactions.
- It is used as an important reagent in organic chemistry as a Lewis acid.
- It undergoes rapid halide exchange reactions
BF3 + BCl3 → BF2Cl + BCl2F
- It is electron deficient hence, acts as Lewis acid that forms adducts with Lewis bases.
BF3 + (C2H5)2O → BF3.O (C2H5)2
- It reacts with water to give boric acid and fluoroboric acid.
4BF3 + 3H2O → 3HBF4 + B(OH)3
- As water softener and cleansing agent.
- In the laboratory for borax bead test.
- It is used in the manufacture of heat resistant borosilicate glass (pyrex). It is used as a stiffening agent for candle milks and used for glazing paper and playing cards.
- Its aqueous solution is basic in nature due to hydrolysis
Na2B4O7 + 2H2O → 2NaOH + H2B4O7]
- Action of heat
(Na2B4O7.10H2O) → Na2B4O7 → 2NaBO2 + B2O3
- Action of ethyl alcohol and sulphuric acid
Na2B4O7 + H2SO4 + 5H2O → Na2SO4 + 4H3BO3
H3BO3 + 3C2H5OH → B(OC2H5)3 + 3H2O
Boric acid (H3BO3)
- It is used in the manufacture of heat resistant borosilicate glass.
- The aqueous solution of boric acid is used as a mild antiseptic especially as eye wash under the name boric lotion.
- It is used as a food preservative in food industry.
- It is used in the manufacture of pigments and borax.
- It is a weak monobasic acid. It is not a protonic acid but acts as Lewis acid.
B(OH)3 + 2HOH → [B(OH)4]– + H3O+
- For preparing a number of borohydrides such as LiBH4, NaBH4, etc.
- As a reducing agent in organic reactions.