Which of the following solutions represent a buffer system? Select all that apply.

Answer
A.
H2CO3 and HCO3-
B.
HNO2 and NaNO2
C.
NH4Br
D.
Na2SO4
E.
HClO4 and NaClO4
F.
CH3COOH

A buffer is made by using a mixture of a weak acid and its conjugate or a weak base and it's cnjugate OR a mixture that will produce such.

A yes
B ?
C no
D no
E ?
The ? are left for you.

To determine which of the given solutions represent a buffer system, we need to understand what a buffer system is. A buffer system is a solution that resists changes in pH when small amounts of acid or base are added to it. Buffer systems typically consist of a weak acid and its conjugate base or a weak base and its conjugate acid.

Let's analyze each given option:

A. H2CO3 and HCO3-: H2CO3 is a weak acid, and HCO3- is its conjugate base. This combination represents a buffer system. Select option A.

B. HNO2 and NaNO2: HNO2 is a weak acid, and NaNO2 is its conjugate base. This combination represents a buffer system. Select option B.

C. NH4Br: NH4Br is a salt and does not contain a weak acid or its conjugate base. This does not represent a buffer system.

D. Na2SO4: Na2SO4 is a salt and does not contain a weak acid or its conjugate base. This does not represent a buffer system.

E. HClO4 and NaClO4: HClO4 is a strong acid, and NaClO4 is a salt. This combination does not represent a buffer system.

F. CH3COOH: CH3COOH is a weak acid. Although it doesn't have its conjugate base, it can form a buffer system when mixed with a salt containing its conjugate base, such as NaCH3COO. However, since this option doesn't provide the salt, it does not represent a buffer system.

In conclusion, options A and B (H2CO3 and HCO3-, and HNO2 and NaNO2) represent buffer systems.