Chapter 8 Acids, bases, Salts, Lewis diagrams and Organic compounds

Almost all the compounds we have studied so far are inorganic compounds…such as H20, CO2, Fe2O3, NaCl, Al2(SO4)3, K3N…etc Inorganic compounds are either Ionic Covalent (molecular) Acids, bases, salts

Acids: they release H (hydrogen ions) in solutions Ex: Note: they all start with H

Bases: they release OH (hydroxide ions) in solutions Ex: Note: they all end with OH

Salts: release positive and negative ions other than H or OH Ex:

Really easy Follow the previous rules we learnt Ex: HCl HNO3 H2SO3

NaOH Ca(OH)2 Al(OH)3

 They don’t start with H or end with OH KCl NaNO3 Na2SO4

Indicators are used to test for acids and bases … Look at page 203 (table 2) Pay attention to the changes of colours that happen Methyl orange is _________ in acid is _________ in base Check the chart in data booklet

 Acids start with H, and produce H ions in solutions. Therefore, acids have more H than they do OH  Bases ends with OH, and produce Oh ions in solutions. Therefore, bases have more Oh ions than they do H ions  When H = OH  neutral solutions knowns as salts

 Look at Fig 6 page 205 VERY IMPORTANT!

 Look at Fig 6 page 205 VERY IMPORTANT! The pH scale allows chemists to quickly determine the acidity of solutions. Ex: apple have a pH=3 means they are _______ soap has a pH= 10 means it is _________

Gilbert Newton Lewis I’m so tired of writing all those useless inner electrons, in the Bohring models!

Gilbert Newton Lewis Invented “Electron-dot” or “Lewis” Structures

Valence Electrons – electrons in the outermost occupied energy level. Valence electrons can be represented by “dots” drawn around the atom.

Remember the rules…

E XAMPLES F B O Ar Octet Rule : All atoms attempt to achieve a complete valence shell similar to their nearest noble gas.

Lewis structure for ionic compounds

L EWIS STRUCTURE FOR MOLECULES ( MOLECULAR / COVALENT COMPOUNDS )

M ORE EXAMPLES

O RGANIC COMPOUNDS They have carbon,C atoms, as their basis and H … and sometimes they have O, N and other non- metals. Carbon, very special, group 14, so 4 valence electrons. It can form several bonds with other atoms as well as with itself. Carbon contains chains of various lengths and these chains can have all types of branches

O RGANIC COMPOUNDS

H OMEWORK Page 209 6,8,13,15,16 Page 214 2,4,6 Page 220 9