1 / 9

Arrhenius Acids

Arrhenius Acids. Arrhenius acids are substances that dissociate in water to give H 3 O + ions. Stronger acids dissociate to a greater degree than weaker acids. Arrhenius Bases. Arrhenius bases are substances that dissociate in water to give hydroxide ions.

duncan
Télécharger la présentation

Arrhenius Acids

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. Arrhenius Acids • Arrhenius acids are substances that dissociate in water to give H3O+ ions. • Stronger acids dissociate to a greater degree than weaker acids. Chapter 1

  2. Arrhenius Bases • Arrhenius bases are substances that dissociate in water to give hydroxide ions. • Stronger bases (NaOH) dissociate more than weaker bases (Mg(OH)2). Chapter 1

  3. Conjugate Acids and Bases • Conjugate acid: when a base accepts a proton, it becomes an acid capable of returning that proton. • Conjugate base: when an acid donates its proton, it becomes capable of accepting that proton back. Chapter 1

  4. Effect of Electronegativity on pKa • As the bond to H becomes more polarized, H becomes more positive and the bond is easier to break. Chapter 1

  5. Effect of Size on pKa • As size increases, the H is more loosely held and the bond is easier to break. • A larger size also stabilizes the anion. Chapter 1

  6. Effect of Resonance on pKa • If the negative charge on an atom can be delocalized over two or more atoms, the acidity of that compound will be greater than when the negative charge cannot be delocalized. • The ethoxide anion is less acidic than the acetate ion simply because the acetate ion can delocalize the negative charge. • Methanesulfonic acid can delocalize the charge in three different resonance forms, making it more acidic than the acetate ion. Chapter 1

  7. Lewis Acids and Lewis Bases • Lewis bases are species with available electrons than can be donated to form a new bond. • Lewis acids are species that can accept these electrons to form new bonds. • Since a Lewis acid accepts a pair of electrons, it is called an electrophile. Chapter 1

  8. Nucleophiles and Electrophiles • Nucleophile: Donates electrons to a nucleus with an empty orbital. • Electrophile: Accepts a pair of electrons. • When forming a bond, the nucleophile attacks the electrophile, so the arrow goes from negative to positive. • When breaking a bond, the more electronegative atom receives the electrons. Chapter 1

  9. Nucleophiles and Electrophiles Chapter 1

More Related