01.07 Acids & Bases (acid base balance)

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Included In This Lesson



  1. Acids- solutions that contain more hydrogen ions or hydronium ions than hydroxide ions. (pH below 7 to 0)
  2. Bases-solutions that contain more hydroxide ions than hydrogen ions or hydronium ions (pH above 7-14)
  3. pH is German for “the potenz/potential to make a H ion”.
    1. Negative log number measures amounts of H+ to OH- as water dissociates
    2. When H+ (H3O+) = OH- pH is 7 and considered neutral
    3. When H+ (H3O+) > OH- pH is below 7 and considered Acidic
    4. When H+ (H3O+) < OH- pH is above 7 and considered Basic
    5. Vaules close but below 7 are weak acids whereas values close but above 7 are weak bases
    6. Buffers produced by the body to bring pH levels back in homeostatic range


Hello there! Today our lesson is on understanding acids and bases.

So acid is defined by the number of hydrogen ions or more specifically how many hydronium ions there are in a solution compared to the number of hydroxide ions. So a water or H2O  molecule looks like a Mickey Mouse and the ears of Mickey are the hydrogens. And liquid water molecules are constantly colliding into one another and at any given time a Mickey mouse can lose an ear or gain one as these polar molecules interact. Pure water will have an equal or balanced amount of hydrogens or hydronium ions to hydroxide ions. But when the solution has and unbalanced amount of these and in this case has more Hydrogen ions and hydronium ions than hydroxide ions the solution is said to be acidic. So some great examples of this in life is hydrochloric acid, carbonic acid, uric acid, ascorbic acid and acetic acid. 
A solution that contains more hydroxide ions than hydrogen ions or hydronium ions is called a base. Examples of a base include baking soda, soap, milk of magnesia, egg shells and bleach. Bases tend to be bitter in taste and slimy to the touch.

And a great way to measure how acidic or basic a solution is is by measuring its pH. pH which is thought to mean “the potential to make hydrogen ions” and it actually measures the H+ or H30+ ions in a solution. So when a solution is neutral there is a 10^-7 M concentration of hydronium ions and equally, there is a 10^-7 M concentration of hydroxide ions.  The pH scale is based on that negative logarithmic value of 10 to the negative 7th power. So when both are at that we say the pH is 7. Should the Hydronium concentration increase and an increase in a negative number would be to go from say -7 to -4 (-4 is bigger than -7) then the pH value drops as the concentration of hydronium ions increases. When the hydroxide values are greater than the hydronium values we say it has a pH greater than 7 and that it is basic.

So here are some common solutions found in life and their pH values. The location has a lot to do with the pH levels and the function of different solutions. So, for example, the stomach has a  pH that is very low to aid in digestion. Lysosomes and the pH of our skin are both working hard to break down foreign materials and acid solutions can definitely assist with that. Most solutions in the human body hover around 7. However, that doesn’t happen magically. Feedback mechanisms work really well if the pH of saying the blood shifts too far from normal (7.35-7.45. To maintain that critical range the body will release what are known as buffers to bring back pH levels to normal. If it leans towards being more acidic the body will secret a weak base and vice versa. Maintaining Homeostasis is crucial and constant for survival.

So to review acids are solutions that have a higher number of hydrogen or hydronium ions than hydroxides and have a pH under 7. Bases are just the opposite in that the -OH levels are higher than the H30+ and the pH level is above. pH is an important measure of these ion concentrations, especially in life and it measures the amount of H+/H30+ ions in a given solution. And since balanced pH levels are so important to live organisms buffers are constantly being made to maintain homeostasis.

Thank you for reviewing the Acids and bases in this lesson. Now go out and be your best self today and Happy Nursing.