B+H2SO4→A+SO2
B+HNO3→A+NO2A is
H3BO3
H3BO2
H3BO
B+HNO3→A+NO2 A is
Na2B4O7+2HCl⟶2NaCl+A Na2B4O7+H2SO4→Na2SO4+A. A is?
HNO2+2H2SO3+H2O→NH2OH+2DThen ‘D′ is