Răspuns:
Na2SO4
a). r.a. Na:S:O=2:1:4
b) r.m. Na:S:O=46:32:64=23:16:32
c) Compozitia procentuala
MNa2SO4=2x23+32+4x16=142g/mol
42g Na2SO4.............46g Na.............32g S............64g O
100g.............................x%Na....................y%S..................z%O
x=46x100/142=32.39%Na
y=32x100/142=22.53%S
z=64x100/142=45.07%O
d) n=m/M
m=nxM=3x142=426g Na2SO4
142Na2SO4..............46gNa
426gNa2SO4..............zgNa
z=426x46/142=138gNa
e)142g Na2SO4..............32gS
xg Na2SO4..................64gS
x=142x64/32=284gNa2SO4
f) n=m/M=14,2/142=0,1 moli Na2SO4
Explicație: