Naked Science Forum

Non Life Sciences => Chemistry => Topic started by: DianaL on 20/05/2009 00:30:04

Title: What is an acid?
Post by: DianaL on 20/05/2009 00:30:04

DianaL asked the Naked Scientists:
   
Hullo,

I am an Nurse and I'm studying Iv therapy at the moment. However I
am quite confused at the moment about the subject of pH. My textbook
states that "electrolytes that release hydrogen atoms (H+) in water are
called acids" it then goes on to state "solutions with more hydrogen
ions (H+) than hydroxyl ions are (OH-) are said to be acidic" but later
when speaking of imbalances of these ions in the body it states "the
more hydrogen ions in a solution the more alkaline it is, the less
hydrogen the more acid the solution will be".

To complicate matters more I asked a fellow nurse working with me and she stated the latter was true the lower the pH the more acidic but to me it doesn't make sense if (H+) is called an acid your advice would be most helpful,

Thank You & All the Best,
Nicole Long

What do you think?

Title: What is an acid?
Post by: Chemistry4me on 20/05/2009 05:12:43

Quote from: DianaL

My textbook states that "electrolytes that release hydrogen atoms (H+) in water are
called acids" it then goes on to state "solutions with more hydrogen ions (H+) than hydroxyl ions are (OH-) are said to be acidic"

Unless the definition of an acid has changed recently, this part of the text is correct. The lower the pH the more acidic it will be.

Quote from: DianaL

but later when speaking of imbalances of these ions in the body it states "the
more hydrogen ions in a solution the more alkaline it is, the less hydrogen the more acid the solution will be".

Perhaps the text was talking about some kind of pH buffering system in the body where adding H⁺ would cause the equilibrium to move in the other direction, forming a more basic solution and decreasing the H⁺ would have the opposite effect?

Title: What is an acid?
Post by: Bored chemist on 20/05/2009 06:51:26

This
"the more hydrogen ions in a solution the more alkaline it is, the less hydrogen the more acid the solution will be".

is simply wrong.
It's the wrong way round.

Title: What is an acid?
Post by: lightarrow on 20/05/2009 08:06:36

<<but later
when speaking of imbalances of these ions in the body it states "the
more hydrogen ions in a solution the more alkaline it is, the less
hydrogen the more acid the solution will be".>>

"The more alkaline it is" what? The solution which it was talking? Then it's wrong, as Bored Chemist said.
But if it refers to something else...
Can you explain better?