1. Provide a definition of an Arrhenius acid and an Arrhenius base. What has science determined to be the limitations of these definitions (in other words, what makes this definition incomplete or lacking)?

See Explanation ( = same answer for earlier question)

Explanation:

The Arrhenius acid-base theory defines an acid as a compound which when added into water increases the hydronium ion (H₃O⁺) concentration and the base as a compound which when added into water increases the hydroxide (OH⁻) ion concentration. As such, an acid-base reaction is limited to proton transfer to only OH⁻ ions forming water. Such would imply that all acid-base reactions produce water only in addition to a salt. This is not always the case as conjugate base anions for many substances can receive proton transfer.

Example: The reaction HOAc + NaCN => HCN + OAc-  will occur in aqueous media because the proton (H⁺) on acetic acid (HOAc) will transfer to the cyanate ion forming hydrocyanic acid (HCN). Such occurs because the CN⁻ ion is a stronger conjugate base than the acetate ion (OAc⁻) and forms the more stable weak acid.  Such is the basis of the Bronsted-Lowry Acid-Base system and states that an acid (proton donor) will transfer its ionizable hydrogen to a conjugate base (proton acceptor) if the transfer forms a weaker acid.

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