Deuterium oxide(D20, where D is deuterium, the hydrugen2 isotope) has an ion product constant, Kw, of 8.9 x 10^16 at 20 degrees celsius. Calculate [D+] and [OD] for pure(neutral) D2O at this temperature.
1 Answer

wow, i would not have guessed its K is so far from H2O’s K
[D+] [OD] = 8.9 e16
take the square root
[D+] = [OD] = 2.98 e8
your answer: [D+] = [OD] = 3.0 e8
p.s. it has a “pD” of 7.5