x---------20
CaCl2---CaCO4
111----100
x=111*20/100=22,2г кальцій хлориду.
2Fe + 3Cl2 = 2FeCl3 FeCl3 + 3NaOH = Fe(OH)3 + 3NaCl 2Fe(OH)3= Fe2O3 + 3H2O Fe2O3 + 3H2= 2Fe + 3H2O Fe + 2HCl= FeCl2 + H2
1.CuO + 2HCl = CuCl₂ + H₂O
2.CuCl₂ + 2NaOH = Cu(OH)₂ + 2NaCl
3.Cu(OH)₂ = CuO + H₂O
4.2CuO = 2Cu + O₂
<span>CH4=C+2 H2;</span>
<span>2 KCIO3=2 KCI+3O2</span>
<span>2 NH3=N2+3 H2</span>
+2 -2 0 +2 -2
CO2 + C = 2CO
0 +2
C -2e = C | ок-ся, вост-ль
+1 +4 -2 +1 +5 -2 +1 -2 +2 -2 +1 +5 -2
Na2CO3 + HNO3 = H2O + CO2 + NaNO3
+4 +2
С +2е = С | вост-ся, ок-ль