Buffer Definition

[Joshua Eidam 2A]

Could someone clarify for me what a buffer exactly? I am confused as to both what they are and what their intended purpose is? Also, how do you identify them?
Thanks

[Valerie Tran 2B]

A buffer is an aqueous solution containing a weak acid and its conjugate base or a weak base and its conjugate acid. A buffer's pH changes very little when a small amount of strong acid or base is added to it. It is used to prevent any change in the pH of a solution so you would use it in an experiment that requires specific and stable pH values.

[Courtney Situ 2B]

Hi there!
A buffer is a solution that can resist pH changes. They're super important for biological systems because these systems need to maintain homeostasis and avoid dramatic changes. Therefore, a lot of biological systems will have buffers. One example of these systems is the bicarbonate buffer system in blood. Blood contains H2CO3 and NaHCO3.

H₂CO₃ + H₂O ⇌ H₃O⁺+ HCO₃⁻

Since H3O+ determines pH, this buffer system serves to maintain the same H3O+ concentration. If there are too many H3O+, it will react with the bicarbonate and form water and carbonic acid (which removes the H3O from the system). If there are too little H3O+, the carbonic acid will revert into H3O+ and HCO3-.

Buffers are always solutions of a WEAK ACID (or base) AND ITS SALT/conjugate. In the above example, H2CO3 is the weak acid and NaHCO3 is its salt. The important thing to remember is that NaHCO3 contains the conjugate that we need.

Hope this helps :))

[rita_debbaneh2G]

A buffer is a solution that resists pH change when an acidic or basic compound is added. It's composed of a conjugate acid and conjugate base that are present in equilibrium, and they neutralize acids and bases in the form of hydronium and hydroxide ions.

[Esmeralda_Solis_2D]

It's the resistance to change in the pH on an addition of an acid or base.