H2SO4 + 2KOH -> K2SO4 + 2H2O
xг/100г = 0.4 моль/1 моль
x= 100*0.4/1 = 40 г.
m розч. = 40*100/15 = 266.6
1. 2KOH + 2H2S = K2S + 2H2O
2. 3LiOH + H3PO4 = Li3PO4 + H2O
3. 2NaOH + H2SO3 = Na2SO3 + H2O
4. Ba(OH)2 + 2HCl = BaCl2 + H2O
5. 2Al(OH)3 + H2SO3 = Al2(SO3)3 + H2O