Equilibrium between para and ortho hydrogen

To calculate at what temperature the equilibrium ratio of ortho to para is 1 1 for Hg and 3 1 for Dg respectively. 

The equilibrium ratios are given by the formulae due to Dennison Proc. Roy. Soc. A 1927, 115, 483) 

Eadi of these ratios has. to be equated to the prescribed value and the equation in solved numerically by successive approximations. We obtain the first approximation by neglecting aU but the leading terms in numerator and denominator. 

Ignoring all but the leading terms we obtain as a first approximation 

Substituting this approximate value in the higher terms we obtain 1.0070 = 9e- f/2 X 1.0000 1.0035 

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