Ca3(PO4)2 + 4H3PO4 = 3Ca(H2PO4)2
2NH3 +H2SO4 = (NH4)2SO4
2NH3↑ +2H(+) +SO4(2-) = 2NH4(+) +SO4(2-)
2NH3↑ +2H(+) = 2NH4(+)
При контакте с водой коррозия олово замедлиться.
Ответ: 4.
<span>1)CO2+2NaOh=Na2CO3+H2O
</span><span>Na2CO3+2HCL=2NaCL+H2O+CO2
</span><span>CO2+Ca(OH)2=CaCO3+H2O
</span>
2)<span>2Ca+O2=2CaO </span>
<span>CaO+H2O=Ca(OH)2 </span>
<span>Ca(OH)2+2HNO3=Ca(NO3)2+2H2O </span>
<span>Ca(NO3)2+H2SO4(разб.) =CaSO4(осадок) +2HNO3
3)</span><span>ZnO + SO3→ ZnSO4 </span>
<span>ZnSO4 + 2NaOH →Zn(OH)2↓ + Na2SO4 </span>
<span>Zn(OH)2/t →ZnO + H2O
4)</span><span>4Al+3O2---> 2AL2O3 </span>
<span>Al2O3 +3H2SO4= AL2(SO4)3 +3H2O </span>
<span>AL2(SO4)3 +6NaOH= 2AL(OH)3 +3Na2SO4
</span><span>2Al(OH)3 - 3Н2О -> Al2O3
</span>
5)<span>Fe2(SO4)3 + 6KOH = 2Fe(OH)3 + 3K2SO4 </span>
<span>2Fe(OH)3 (t)--> Fe2O3 + 3H2O </span>
<span>Fe2O3 + 3H2SO4 = Fe2(SO4)3 + 3H2O
Спасибо+лучший.</span>