4fe+3O2→2FE2O3
m (4fe)=28г
m (fe)=7г
n (fe)=7/56=1/8моль
m (0)=1/8*16=2г
28г+12г=ho2
1) m (fe2o3)=4O2
2) n=40=1,5моль.
С водой...................................................................................
C6H5CH3
w(C)=7*!2/92=0,913 или 91,3%
w(H)=8/92=0,087 или 8,7%
M(8O)=8*16=128g/mol
M(3O2)=3*16*2=96g/mol
M(Fe2O3)=56*2+16*3=160g/mol
M(H2SO3)=1*2+32+16*3=82 g/mol