Semiheavy water explained

Semiheavy water is the result of replacing one of the protium in normal water with deuterium.^[1] It exists whenever there is water with light hydrogen (protium, H) and deuterium (D or H) in the mix. This is because hydrogen atoms (H and H) are rapidly exchanged between water molecules. Water containing 50% H and 50% H, is about 50% HHO and 25% each of HO and HO, in dynamic equilibrium.^[2] In normal water, about 1 molecule in 3,200 is HDO (one hydrogen in 6,400 is H). By comparison, heavy water DO^[3] occurs at a proportion of about 1 molecule in 41 million (i.e., one in 6,400). This makes semiheavy water far more common than "normal" heavy water.

The freezing point of semiheavy water is close to the freezing point of heavy water at 3.8°C compared to the 3.82°C of heavy water.

See also

• Deuterium-depleted water

Further reading

• Schwarzer D, Lindner J, Vöhringer P . Energy relaxation versus spectral diffusion of the OH-stretching vibration of HOD in liquid-to-supercritical deuterated water . The Journal of Chemical Physics . 123 . 16 . 161105 . October 2005 . 16268674 . 10.1063/1.2110087 . 2005JChPh.123p1105S . 11858/00-001M-0000-0012-E7B7-2 . free .

Notes and References

1. Tashakor S . 2016-09-28. Neutronic Investigation of Semi-Heavy Water Application in Hplwr New Flow Pattern . CNL Nuclear Review. en. 1–5. 10.12943/CNR.2016.00019 . free.
2. Goncharuk VV, Kavitskaya AA, Romanyukina IY, Loboda OA . Revealing water's secrets: deuterium depleted water . Chemistry Central Journal . 7 . 1 . 103 . June 2013 . 23773696 . 3703265 . 10.1186/1752-153X-7-103 . free .
3. Web site: Heavy water chemical compound. Encyclopedia Britannica. en. 2019-04-24.