a. the normal Aa gradient is <age/4
B. in respiratory alkalosis, for every drop of 10mmHg of pCO2, the HCO3- drops 1 mmol/L acutely
c. in chronic respiratory alkalosis, for every drop of 10mmHg of pCO2, the HCO3- drops 2mmol/L
d. in acute respiratory acidosis, for every 10mmHg rise in pCO2 ,the HCO3 rises 1mmol/L
e. in chronic respiratory acidosis, for every 10mmHg rise in pCO2 ,the HCO3 rises 2mmol/L