e2O3+H2O
O2 + C = CO2
<span>2K + Cl2 = 2KCl</span>
<span><span>P4 + 3O2 = 2P2O</span></span>
<span><span>N2O5 + H2O = 2HNO33</span></span>
HgO=Hg+O2
2Fe(OH)3 =при нагревании Fe2O3 + 3H2O
n(Н3РО4)=m/M= 490/98=5 моль