Question

Determinati formula moleculara a substantei care are 40%C,6.6%H stiind ca 1 g din acea substanta ocupa in conditii normale un volum de 746.6mL.Vreau rezolvare completa si argumentata!

Answer 1

deduc masa molara, din egalitatile
n= m/M
n=V/Vm---> m/M= V/Vm----> M=mxVm/V=1x22,2/0,7466= 30g/mol

deduc formula moleculara
100g substanta.....40gC.....6,6gH......(100-40-6,6)g O
  30g.......................x................y................z
x=12gC
y=1.98gH=2gH
z=16gO

n=m/M
n,C= 12g/12g/mol= 1mol C
n,H= 2g/1g/mol= 2molH
n,O= 16g/16g/mol= 1molO--->
 CH2O