Răspuns:
MK2SO4=2×39+32+4×16=174f/mol
174gK2SO4.........................78gK............32gS...............64gO
87gK2SO4...........................xgK..................ygS..................zgO
x=87×78/100=calculeaza
y=32×97/100=calculeaza
z=64×87/100=calculeaza
Explicație: