To keep blood PH at 7.4 the HCO3 : H2CO3 ratio should be_____________? / Biochemistry, General Biochemistry, Medical Mcqs / By admin To keep blood PH at 7.4 the HCO3 : H2CO3 ratio should be_____________? A. 20 : 1 B. 30 : 1 C. 15 : 1 D. 1 : 1