Mр-ра=500 г
wв-ва=20\%
mв-ва-?
w=mв-ва/mр-ра
mв-ва=w*mр-ра=0,2*500=100 г
As⁻³H₃⁺¹
F₂⁰
Mn⁺²(P⁺⁵O₄⁻²)₂
I₂⁺⁵O₅⁻²
Pb⁺²(C⁺⁴O₃⁻²)₂
Mn⁺⁴Br₄⁻¹
Mn⁺²Cl₂⁻¹
MnBr - такого соединения нет
1.M=24+14*2+16*3*2=148
2.N2+3H2=2NH3
4 Al+3O2=2Al2O3
3.Сера
W(H)=2/98*100%=2%
w(S)=32/98*100%=33%
w(O)=100-2-33=65%
K2O+H2O=2KOH
N2O5 + H2O = 2HNO3
Na2O+2HCl=2NaCl+H2O
Na2O+2HNO3=2NaNO3+H2O
3Na2O+2H3PO4=2Na3PO4+3H2O
SiO2 +4NaOH =Na4SiO4 +2H2O
2NaOH+N2O5=2NaNO3+H2O.
Ba(OH)2 + CO2 = BaCO3 ↓ + H2O
NaOH+HCl= NaCl+H2O.
2NAOH+H2SO4=NA2SO4+2H2O
3NaOH+ 2H3PO4 =2Na3PO4+3H2O