Răspuns:
Explicație:
K2SO4
M=2.39 +32 +4.16=174---------->174g/moli
174g K2SO4-----------------78g K----------32gS --------------64gO
100g--------------------------------x----------------y-----------------------z
x=100.78 :174=44,82% K
y=100.32 : 174=18,40 % S
z=100.64 : 174=36,78 % O