144. (V16-126-36) Metall sulfati kristallogidrati va NA2S-4H20 ning quruq aralashmasi (ca(H20) = 43,9%) 214 ml suvda eritilganda 18,6 g metall sulfidi chokib, hosil bolgan 278,4 g eritmadagi yagona elektrolit Na2S04 ning molyalligi 0,8 mol/kg ga teng boldi. Dastlabki aralashmadagi Na2S-4H20 ning massasini (g) aniqlang.
A) 36 B)30
C) 48
D) 54