Boric acid reacts with sodium hydroxide to form sodium metaborate and sodium tetraborate.
H3BO3 + NaOH ———> NaBO2 + 2H2O
4H3BO3 + 2NaOH ———> Na2B4O7 + 7H20
Action Of Heat:
Boric acid heated above 170 degree Celsius to gives metaboric acid.
4H3BO3 ———> 4HBO2 + H20
Boric acid heated above 300 degree Celsius to gives tetraboric acid.
4HBO2 ———> H2B4O7 + H2O
Tetraboric acid heated above 330 degree celsius to gives boron trioxide.
H2B4O7 ———> 2B2O3 + H2O
Action Of Ethyl Alcohol:
Boric acid reacts with ethyl alcohol in the presence of concentrated sulphuric acid to form triethylborate. The ethyl borate burns with green edged flame.
4H3BO3 + 3C2H5OH ———> B(OC2H5)3 + 3H2O
Action Of Calcium Fluoride:
Boric acid reacts with calcium fluoride in the presence of concentrated sulphuric acid to gives boron trifluoride.
2H3BO3 + 3CaF2 + 3H2SO4 ———> 2BF3 + 3CaSO4 + 6H2O