Question

Determinati formula moleculara a substantei care contine 54.55%C, 36.36%O si 9.09%H, stiind ca 11 mg de substanta ocupa, in conditii normale, un volum de 5.6 ml. (R: C2H4O)

Answer 1

Răspuns:

Explicație:

deduc masa molara a substantei, stiind ca numarul de moli se poate calcula astfel:

niu=m/M=V/Vm

11mg/M,mg/mmol=5,6ml/22,4-ml/mmol--- > M= 44mg/mmol=44g/mol

100g substanta.........54,55gC.....36,36gO.....9,09gH

44g..............................x...............................y... ...........z

x=24gC----> niu=m/M=24g/12g/mol= 2molC

y=16gO----> niu= 16g/16g/mol= 1molO

z=4gH-----> niu= 4g/1g/mol=4molH

SUBSTANMTA ESTE     C2H4O