[johnsy123]

An unknown organic compound was analysed to determine its identity. The compound contained only carbon, hydrogen and oxygen and did no contain any carbon-carbon double bonds. When completely oxidised in air, 8.20g of the compound produced 8.19g of water and 20.2g of carbon dioxide.

a) i) based on the mass of water produced by the oxidation, calculate the mass of hydrogen in the 8.20g sample of compound.
   
   ii) Based on the mass of carbon dioxide produced by oxidation, calculate the mass of carbon in the 8.20g sample of compound

   iii) Determine the mass of oxygen in 8.20g sample of compound.

then determine empirical formula.

[Nobby]

Start in this way. Calculate the amount of hydrogen, what you have in the 8.19 g water and the carbon what is in 20.2 g carbon dioxide.

Ratio calculation. m₁xM₁= m₂/yM₂

m_1,2 mass
M_1,2 molecular mass
x,y coefficients = how many atoms in the calculated molecule. For example water has 2 H and x for  H is 2.

If you have this two masses, then you can subtract it from the given mass of the compound to get the amount of oxygen.

The next step is to conwert all masses into mol

You will get a mol ratio C:H:O

The carbon you set to 1 and calculate the other two elements. If still abroken number multiply so often until all numbers not broken anymor.