2Zn + O₂ = 2ZnO
ZnO + HNO₃ = Zn(NO₃)₂ + H₂O
Zn(NO₃)₂ + CaCO₃ = ZnCO₃↓ + Ca(NO₃)₂
ZnCO₃ + MgCl = ZnCl₂ + MgCO₃↓
FeSO4 = Fe (+2) + SO4(-2)
K3PO4 = 3K (+1) + PO4(-3)
Cu(NO3)2 = Cu(+2) + 2NO3(-1)
NaOH = Na (+1) + OH(-1)
а)Fe2O3
= Мr(Fe2O3)= Аr(Fe)·56×2+Ar(O)·16×3=160
W(fe)= 2*56/160 = 0.7 = 70%
W(O)= 3*16/160 = 0,3 = 30%
б)Fe3O4
=Mr(Fe3O4)= 56×3+16×4= 232
W(Fe)=3*56/232 ·100%= 168:232·100%=72.4%
W(O)= 4*16/232·100%=64:232·100%=27.5%
в)FeO
=Mr(FeO)= 56+16=72
W(Fe)=56/72·100%=77.7%
W(O)=16/72·100%= 22.2%
г)FeS=Mr(FeS)=56+32=88
W(Fe)=56/88·100%=63.3%
W(S)= 32/88·100%=36.3%
S + O2 = SO2
2SO2 + O2 = 2SO3
K2O + SO3 = K2SO4
K2SO4 + Ba(OH)2 = 2KOH + BaSO4
KHCO3+H-OH=KOH+H2CO3;
степень, вроде, 30%