which of the following represent a buffer system?
A.) NaOH and NaBr
B.) HF and NaF
C.) HC2H3O2 and C12H22O11
D.) HCl and KOH
A buffer is
a. a weak acid mixed with a salt of the weak acid. (example: acetic acid and sodium acetate)
b. a weak base mixed with a salt of the weak base. (example: NH3 + NH4Cl)
c. a combination of salts/acids OR salts/bases that produce either a or b above. (examples: HCl + excess sodium acetate OR NaOH + excess NH4Cl)
To determine which of the following options represents a buffer system, we need to understand what a buffer system is. A buffer system is a solution that can resist changes in pH when small amounts of acid or base is added.
A buffer system typically consists of a weak acid and its conjugate base or a weak base and its conjugate acid. This allows the system to accept or donate protons (H+) to maintain a relatively constant pH.
Let's examine each option to see if it meets the criteria:
A) NaOH is a strong base, and NaBr is a salt. This combination does not contain a weak acid or a weak base, so it does not represent a buffer system.
B) HF is a weak acid, and NaF is its conjugate base. This combination does contain a weak acid (HF) and its conjugate base (NaF), which means it represents a buffer system.
C) HC2H3O2 is acetic acid, a weak acid, and C12H22O11 is a sugar and not a base or a salt. This combination contains a weak acid (HC2H3O2), so it represents a buffer system.
D) HCl is a strong acid, and KOH is a strong base. This combination does not contain a weak acid or a weak base, so it does not represent a buffer system.
Based on the analysis, options B (HF and NaF) and C (HC2H3O2 and C12H22O11) represent buffer systems.
The answer is B.) HF and NaF.
A buffer system consists of a weak acid and its conjugate base (or a weak base and its conjugate acid). In this case, HF is a weak acid and NaF is its conjugate base. Therefore, option B represents a buffer system.