Physiology Haemoglobin is the major buffer in blood, bicarbonate ions diffuses out of erythrocyte into plasma in exchange of: A Potassium B Phosphate C Carbonic acid D Chloride ion 💡 Explanation Haemoglobin is the major buffer in blood, bicarbonate ions diffuses out of erythrocyte into plasma in exchange of: ✓ Correct Answer: D. Chloride ion