Original ring analysis of saturated mineral oil fractions

If it is assumed that the number of carbon atoms in the average molecule of the oil fraction is c and the number of hydrogen atoms h then the molecular formula is CcH. If the number of rings in the average molecule is R, this formula can also be represented by 

For the molecular weight M it follows from the given molecular formula that 

By means of equation (1) the number of rings in saturated mineral oil fractions can be calculated if %H and M are known. 

The number of rings in saturated mixtures of hydrocarbons can also be read from the graph in Fig. 3, which represents equation (1) in the form 

Both the refractive index and the density are measured at the same temperature, e.g. 20°C. The refractive index is generally measured for the sodium D-line. In the fol- 

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