Question

Oblicz zawartosc procentowa -masowa wody w hydrantach:
a)CaSO4*2H2O
b)CoCl2*2H2O

Answer 1

M(masa cząsteczkowa całego hydratu):
a)M CaSO₄ × 2H₂O= 40g/mol + 32g/mol + 4×16g/mol + 4 × 1g/mol + 2×16g/mol=172g/mol

M 2H₂O= 2× ( 2×1g/mol + 16g/mol)= 36g/mol

172g/mol CaSO₄ × 2H₂O----to jest-----100%
36g/mol 2H₂O-----------stanowi--------X %
X= 36g/mol × 100% : 172g/mol≈ 21 %
W dwuwodnym siarczanie wapnia woda stanowi ok 21 %.

b)M CoCl₂ × 2H₂O= 59g/mol + 2 × 35,5g/mol + 4 × 1g/mol + 2×16g/mol=166g/mol

M 2H₂O= 2× ( 2×1g/mol + 16g/mol)= 36g/mol

166g/mol CoCl₂×2H₂O----to jest-----100%
36g/mol 2H₂O-----------stanowi--------X %
X= 36g/mol × 100% : 166g/mol≈ 22 %
W dwuwodnym chlorku kobaltu woda stanowi ok 22 %.