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I am a physician and administer 0.9% NaCl in water ("normal saline") to patients frequently. The bag says it has a pH of 5.5 (compared to the human body of 7.4).

I am asking why the pH is so low. It is because NaCl is the salt of HCl? I read on wikipedia that the pH of NaCl aqueous solutions is 7. I teach medical students and want to give an understandable explanation why the pH on a bag of "normal saline" reads pH 5.5 and when we give lots of saline to patients, they develop acidosis in the blood.

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    $\begingroup$ There is an entire article dedicated to this topic, actually:) $\endgroup$ – andselisk♦ Jan 3 '18 at 22:39
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    $\begingroup$ Wow. Thank you for the super fast replies!!! That is awesome. I will go through the article you linked and see what it has to say. Much appreciated. $\endgroup$ – Jason Jan 3 '18 at 22:45
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    $\begingroup$ It would seem that a normal saline solution isn't buffered at pH 5.5. Thus there is really very little acid in an absolute sense. A typical carbonated beverage would have thousands of times more acid. $\endgroup$ – MaxW Jan 3 '18 at 23:33

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