(H2B4O7): 4 HBO2 → H2B4O7 + H2O Further heating (to about 530 °C) leads to borontrioxide: H2B4O7 → 2 B2O3 + H2O When orthoboric acid is dissolved in water, it
synthesis, namely boric acid and borontrioxide, are well known (see boron), the corresponding numbers for the boron nitride are not listed in statistical