Q13 / 155 · WBJEE 2016 · Chemistry
Which statement is not correct for ortho and para hydrogen?
- AThey have different boiling points
- Correct answerBOrtho-form is more stable than para-form
- CThey differ in their nuclear spin
- DThe ratio of ortho to para hydrogen changes with change in temperature
Solution
(i) Ortho and para hydrogens have difterent nuclear spin. In $\mathrm{H}_{2}$ molecule, two protons in two H atoms with pare spin are called ortho-hydrogen
(ii) Ortho-hydrogen is more stable than para form at and above room temperature only, therefore para form always tends to revert in ortho-form. Thus, not correct.
(iii) The per cent composition of ortho and para changes with the lemperature. Thus, their ratio also change.
(iv) They have slightly different boling point.
Hence, (b) is the answer.
(ii) Ortho-hydrogen is more stable than para form at and above room temperature only, therefore para form always tends to revert in ortho-form. Thus, not correct.
(iii) The per cent composition of ortho and para changes with the lemperature. Thus, their ratio also change.
(iv) They have slightly different boling point.
Hence, (b) is the answer.Hence, the correct answer is option: 'B'.