Задача лёгкая, применяем формулы, NA- число Авогадро
Mn+4->Mn 0
Si 0->Si+4
O-2
Mn+4e->Mn 0|4
Si-4e->Si +4|4
2Mn2O3+3Si->3SiO2+2Mn
<span>2NaOH+N2O5 = 2NaNO3 + H2O</span>
<span>2Na(+) + 2OH(-) + N2O5 = 2Na(+) + 2NO3(-) + H2O</span>
<span>2OH(-) + N2O5 = 2NO3(-) + H2O</span>
<span>2NaOH+H2SO4 = Na2SO4 + 2H2O</span>
<span>2NaOH+FeCl2 = Fe(OH)2<span>↓ + 2NaCl</span></span>
<span>AgOH + HNO3 = AgNO3 + H2O</span>