2NaCl + H2SO4 -> Na2SO4 + 2HCl
2HCl + ZnO -> ZnCl2 + H2O
ZnCl2 + 2AgNO3 -> 2AgCl + Zn(NO3)2
<span>а) Na2SO3+H2SO4= Na2SO4+SO2(газ)+H2O (вода)
</span><span>NaOH+HCl= NaCl+H2O (вода)
Fe(OH)3+HNO3= Fe(NO3)2+H2O </span>(вода)<span>
3CaO+2H3PO4= Ca3(PO4)2 (осадок)+3H2O</span>(вода)<span>
б) CO2+2KOH= K2CO3+H2O</span>(вода)<span>
K2S+CuCl2= 2KCl+CuS (осадок)
CuSO4+Ba(OH)2= BaSO4 (осадок)+Cu(OH)2 (осадок)
K2SiO3+2HNO3= 2KNO3+H2SiO3 (осадок)
CaCO3+H2SO4=CaSO4+CO2 (газ)+H2O (вода)
</span><span>Na2SO3+H2SO4= Na2SO4+SO2 (газ)+H2O (вода)
</span>
Если молекулярную формулу, то - О2(кислород)
1. H3PO4 Wелемента =n×Ar/Mречовини
Mреч=1×3+31+16×4=98
W(H)= 3×1/98=0.03
W(O)=4×16/98=0.65
W(P)= 31×1/98=0.31
2.Al2(SO4)3
Mреч=27×2+32×3+16×12=342
W(Al)=27×2/323=0.16
W(O)=16×12/343=0.56
W(S)=32×3/342=0.28
3.NaOH
Mреч= 23+1+16=40
W(Na)=23×1/40=0.575
W(H)=1×1/40=0.025
W(O)=16×1/40=0.4
<span>2Cu</span>2<span>S + 3O</span>2<span> = 2Cu</span>2<span>O + 2SO</span>2
CaCl2 + F2 = CaF2 + Cl2
<span>Na</span>2<span>S + 4HNO</span>3<span>(конц.) = 2NaNO</span>3<span> + 2NO</span>2<span>↑ + S↓ + 2H</span>2<span>O</span>
<span>8NH</span>3<span> + 3Br</span>2<span> = N</span>2<span> + 6NH</span>4<span>Br</span>
<span>Fe + 4HNO</span>3<span> (разб., гор.) = Fe(NO</span>3<span>)</span>3<span> + NO↑ + 2H</span>2<span>O</span>