H3BO3T1⟶×T2⟶YRedhot⟶B2O3
If T1<T2 then X and Y respectively are
X = Metaboric acid and Y = Tetraboric acid
X = Tetraboric acid and Y = Metaboric acid
X = Borax and Y = Metaboric acid
X = Tetraboric acid and Y = Borax
X=Metaboric acid=HBO2Y = Tetraboric acid=H2B4O7