Question

Ratio of ortho and para hydrogen in ordinary hydrogen is:

• A. $1:3$
• B. $2:3$
• C. $3:1$
• D. none of the above

Answer 1

The correct option is C $3:1$

Molecular hydrogen occurs in two isomeric forms, one with its two proton spins aligned parallel (orthohydrogen), the other with its two proton spins aligned antiparallel (parahydrogen). At room temperature and thermal equilibrium, hydrogen consists of approximately $75\%$ orthohydrogen and $25\%$ parahydrogen. So ratio of ortho and para hydrogen in ordinary hydrogen is $3:1$.