Question

Na2SO4 *XH2O cantareste 15g si contine 9.44 g apa.Determinati valoarea lui X?

Answer 1

M H2O = 2· 1 + 16 = 18
M Na2SO4 · x H2O = 2·23 + 32 + 4·16 + x·18 = 142 + 18·x

142 + 18·x  g......................................18·x g H2O
15 g...................................................9.44 g H2O

⇒270·x = 1340,48 + 169,92·x
100,08 · x = 1340,48
x = 1340,48 ÷ 100,08
x = 13,39
se va considera x = 13  ⇒  Na2SO4 · 13H2O