Physiology General 8e2cd6c4 The normal value of P50 on the oxyhaemoglobin dissociation curve in an adult is A 1.8 kPa B 2.7 kPa C 3.6 kPa D 4.5 kPa High-Yield Explanation Adult Hb- 50% saturation at PO2 of 26mmHg. 1mmHg= 0.133 KPa 26mmHg= 0.133 X 26 = 3.45