1 / 21

Acid Base Theories

Acid Base Theories. Important Definitions and Ideas. Arrhenius Acids and Bases. States that ALL Acids release a Hydrogen ion (H+) in water Also states that acids react with metals States that ALL BASES MUST have and release OH- ions in water (THIS IS A PROBLEM)

wilsone
Download Presentation

Acid Base Theories

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Acid Base Theories Important Definitions and Ideas

  2. Arrhenius Acids and Bases • States that ALL Acids release a Hydrogen ion (H+) in water • Also states that acids react with metals • States that ALL BASES MUST have and release OH- ions in water (THIS IS A PROBLEM) • Limits his definition of what bases are • States that if a substance does NOT have OH- to give then its not a base

  3. What does AMPHOTERIC Mean? • Amphoteric Substances can be both an acid and a base • Depends on what the reactants are in the reaction • Water is an example of an amphoteric substance but many more exist

  4. Acid Types • 1. Monoprotic----Acids with only one Hydrogen ion to give • Ex: HCl • 2. Diprotic—Acids that have two Hydrogen ions to lose • Must go through 2 rounds of reactions to get rid of both since acids can only lose one Hydrogen per reaction • Ex: H2SO4 • 3. Triprotic—Acids that have 3 Hydrogen ions to lose. • Must go through 3 rounds of reactions to lose all 3 • Ex: H3PO4

  5. Acid Types Continued • The number of Hydrogen ions that can be lost has NOTHING TO DO with Strength • The strongest acids are the ones that the Hydrogen ions the fastest in water • We call this a Ka measurement • Strong Acids have high values and weak acids have low values

  6. Bronsted-Lowry Acids and Bases • Theory that states that acids are any substance that loses at least 1 Hydrogen ion when placed in a reaction • This is the “normal” definition • States that BASES are ANY SUBSTANCE THAT TAKES or GAINS at least ONE HYDROGEN ION. • This is different and is more inclusive and a better definition of what a base is • Substances like Ammonia, and Baking Soda are bases that fit this definition

  7. Bronsted-Lowry Vocabulary • 1. Conjugate Acid-----Substance that the base becomes on the product side of the reaction after it has gained one hydrogen ion • 2. Conjugate Base----Substance that the ACID becomes after it has lost one Hydrogen ion on the product side • If you reverse the reaction you can get back your starting acid/base combination • All Bronsted-Lowry reactions are equilibrium reactions • Shows that acid/base reactions will reach a point of constant concentration

  8. Acid and Base Strength • 1. Strong Acids--- • Ionize completely or nearly to completion • Ionize fast when placed in water or combined with a substance • Create a solution with a high concentration of H+ ions • pH range is typically 1-3 • For every 100 Acid Molecules 95-100 have lost a hydrogen

  9. Weak Acids • Acids that do not ionize completely • This means that some/most of the acid molecules hold onto the Hydrogen that they should be losing • 1 or 2 of every 100 molecules lose a hydrogen when placed into solution • These will be weak and will have a pH of 4---6 • Typically these are organic acids

  10. Strong Bases • Bases that release OH- ions quickly and completely when placed into solution • Or these are bases that aggressively take a hydrogen ion from an acid or from water • pH will be 10-14

  11. Weak Bases • Bases that do not ionize completely (hold onto the hydroxide ions) • OR these bases do not aggressively take hydrogen ions from water or other substances • Most of these bases are molecular substances like Ammonia • pH is from 7.1-10

More Related