Решение
<span>А) Al2O3 + Н2SO4→ реакция обмена
</span>
<span><span>Al2O3
+ 3H2SO4 </span>→t 250 C →<span>Al2(SO4)3
+ 3H2O</span></span>
<span>Б) Al2O3 + H2O → не идет</span>
<span>В) Al2O3 + KOH</span><span>Al2O3 + 2 KOH → 2 KAlO2 + H2O</span>
<span>Или<span> Al</span>2O3 + 6 KOH → 2 K3AlO3 + 3H2O</span>
Mr(NaOH) = 40
W(Na) = 23/40= 58%
W(O) = 16/40= 40%
W(H) 1/40= 2,5%
Mr(Mg(OH)2) = 24 + 32 + 2 = 58
W(Mg) = 41,3%
W(O) = 55%
W(H)= 3%
Mr(C3H8) = 44
W(C) = 81,8%
W( H) = 18%
M(p-pa HNO3)=600*1.45=870 г
m(HNO3)=870*0.5=435 г