Al2(SO4)3
w(Al) = 2Ar(Al)/Mr(Al2(SO4)3) = 54/342 = 0,16 = 16\%
w(S) = 3Ar(S)/Mr(Al2(SO4)3) = 96/342 = 0,28 = 28\%
w(O) = 12Ar(O)/Mr(Al2(SO4)3 = 192/342 = 0,56 = 56\%
K2SO4
w(K) = 2Ar(K)/Mr(K2SO4) = 78/174 = 0,45 = 45\%
w(S) = Ar(S)/Mr(K2SO4) = 32/174 = 0,18 = 18\%
w(O) =4Ar(O)/Mr(K2SO4) = 64/174 = 0,37 = 37\%
P2O5+3H2O=2H3PO4
1. m (H3PO4) 42.6/142=x/98*2 x=58.5
2. m H2O на реакцию 42,6/142=у/3*18 у=16,2
3. m H2O оставшейся = 200-16,2=183,8
4. м раствора= 58,5+183,8=242,3
5. W = 58.5*100/242.3=24.14%
Бром 2 8 18 7
Йод 2 8 18 18 7
1)Zn+2HCl=ZnCl2+H2;
2)ZnCl2+2NaOH=Zn(OH)2+2NaCl.
А второе я не панимаю