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Ответ: Д
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<span>N2 + 3H2 = 2NH3 </span>
<span>NH3 + H2O = NH4OH</span>
<span>3NH4OH + H3PO4 = (NH4)3PO4 + 3H2O</span>
<span> C + 2H2 = CH4(гидрирование) </span>
<span>СН4+2О2=СО2+2Н2О</span>
<span> CO2+MgO = MgCO3</span>
<span> MgCO3 = CO2+MgO</span>
<span>ЦЕПОЧКА:</span>
<span>1) N2</span>
<span>2) H2O</span>
<span>3) H3PO4 </span>
<span>1) H2</span>
<span>2) 2O2</span>
<span>3) MgO</span>
<span>4) </span><span>MgCO3 + H2O + СO2 = Mg(HCO3)2
5) Mg(HCO3)2 = MgCO3(осадок) + H2O + CO2 </span>
Pb(NO3)2 + Na2SO4 = PbSO4 + 2NaNO3
Pb(2+) + 2NO3(-) + 2Na(+) + SO4(2-) = PbSO4 + 2Na(+) + 2NO3(-)
Pb(2+) + SO4(2-) = PbSO4
2,8 г
CaO+H2O -> Ca(OH)2
74 г/моль
Ню(Ca(OH)2)=m/М=2,8 г/74 г/моль=0,04 моль