IDENTIFY THE CONJUGATE ACID-BASE PAIR IN THE FOLLOWING REACTIONS.

A) HSO4^- + SO3^2- <---> HSO3^- + SO4^2-
B) S^2- + H20 <----> HS^- + OH^-
C) CN^- + H3O^+ <----> HCN + H2O
D) H2SE + H2O <----> HSE^- + H3O^+

The one with more H is the acid and the one with one fewer H is the base.

HSO4^- is the acid. SO4^2- is the base.
SO3^2- is the base; HSO3^- is the acid.

so which one is the acid and which one is the base

To identify the conjugate acid-base pairs in the given reactions, we need to understand the concept of conjugate acid-base pairs.

In a chemical reaction, an acid donates a proton (H+) to a base, and the base accepts that proton. The acid is then converted into its conjugate base, and the base is converted into its conjugate acid. The conjugate acid-base pairs always differ by the presence or absence of one proton.

Let's go through each reaction and identify the conjugate acid-base pairs:

A) HSO4^- + SO3^2- <--> HSO3^- + SO4^2-
In this reaction, HSO4^- donates a proton (H+) to SO3^2-, forming its conjugate base HSO3^-. Similarly, SO4^2- accepts the proton, forming its conjugate acid SO3^2-. Therefore, the conjugate acid-base pairs in this reaction are HSO4^-/HSO3^- and SO3^2-/SO4^2-.

B) S^2- + H2O <--> HS^- + OH^-
In this reaction, S^2- donates a proton (H+) to water (H2O), forming its conjugate acid HS^-. Simultaneously, water accepts the proton, forming its conjugate base OH^-. Therefore, the conjugate acid-base pairs in this reaction are S^2-/HS^- and H2O/OH^-.

C) CN^- + H3O^+ <--> HCN + H2O
In this reaction, CN^- donates a proton (H+) to H3O^+, forming its conjugate acid HCN. At the same time, H3O^+ accepts the proton, forming its conjugate base H2O. Therefore, the conjugate acid-base pairs in this reaction are CN^-/HCN and H3O^+/H2O.

D) H2SE + H2O <--> HSE^- + H3O^+
In this reaction, H2SE donates a proton (H+) to water (H2O), forming its conjugate acid HSE^-. Meanwhile, water accepts the proton, forming its conjugate base H3O^+. Thus, the conjugate acid-base pairs in this reaction are H2SE/HSE^- and H2O/H3O^+.

In summary, the conjugate acid-base pairs for the given reactions are:
A) HSO4^-/HSO3^- and SO3^2-/SO4^2-
B) S^2-/HS^- and H2O/OH^-
C) CN^-/HCN and H3O^+/H2O
D) H2SE/HSE^- and H2O/H3O^+

What do you not understand about this? Look for the ion that has an H on one side and one fewer H on the other side. That's all there is to it.