disodium hydrogen phosphate指的是( )
A. NaHPO4
B. Na2HPO4
C. NaH2PO4
D. Na2H2PO4
KNH4HPO4依照系统命名规则应称为( )
A. potassium ammonium hydrogen phosphate
B. ammonium hydrogen potassium phosphate
C. ammonium potassium hydrogen phosphate
D. ammonium potassium diphosphate
英文名中含有pentahydrate的可能是( )
A. CaCl2·2H2O
BeSO4·4H2O
CuSO4·5H2O
D. FeCl3·6H2O
dinitrogen pentoxide的化学式是____。