Question

1. in the reaction below, label the acid, base, conjugate acid, and conjugate base. (p. 8/10) hcl + h₂o → cl⁻ + h₃o⁺ hcl is the ____ h₂o is the __ cl⁻ is the __ h₃o⁺ is the ____

Explanation:

Step1: Recall Acid-Base Definitions

Using the Brønsted - Lowry definition: an acid donates a proton ($\ce{H+}$), a base accepts a proton. A conjugate acid is formed when a base accepts a proton, and a conjugate base is formed when an acid donates a proton.

Step2: Analyze $\ce{HCl}$

$\ce{HCl}$ donates a proton ($\ce{H+}$) to form $\ce{Cl-}$. So $\ce{HCl}$ is the acid.

Step3: Analyze $\ce{H2O}$

$\ce{H2O}$ accepts a proton ($\ce{H+}$) to form $\ce{H3O+}$. So $\ce{H2O}$ is the base.

Step4: Analyze $\ce{Cl-}$

$\ce{Cl-}$ is what remains after $\ce{HCl}$ (the acid) donates a proton. So $\ce{Cl-}$ is the conjugate base.

Step5: Analyze $\ce{H3O+}$

$\ce{H3O+}$ is what is formed when $\ce{H2O}$ (the base) accepts a proton. So $\ce{H3O+}$ is the conjugate acid.

Answer:

• $\ce{HCl}$ is the acid
• $\ce{H2O}$ is the base
• $\ce{Cl-}$ is the conjugate base
• $\ce{H3O+}$ is the conjugate acid