A patient with an acidotic blood pH of 7.3 may be treated with an alkali such as sodium bicarbonate. Why would this treatment raise the pH of the blood?
Because sodium bicarbonate is a base and a higher pH is more basic. Adding a base to an acid will increase the pH to a more basic level. pH scale is from 1 - 14, 14 being extremely basic and 1 being extremely acidic.
Like the question says, sodium bicarbonate is an alkali. On the pH scale <7 is acidic, right around 7 is neutral, and >7 is basic or alkali. So adding an alkali to an acidic system helps the system reach neutral, or in this case with in the range of the normal human blood pH.
Sodium bicarbonate works in opposition with H+/carbon dioxide. Too much bicarb will make the blood basic (called alkalosis), but too little will cause acidosis (like in your example). Bicarb also acts as a buffer in the blood. So if there are too many H+ ions in the blood, causing the pH to fall, the bicarb can bind to the hydrogen ions, buffering them.
Hope that helps! 🙂
More importanly, why are you too lazy to do your own homework? You are just going to fail once the test comes around.