Law of definite composition A compound contains the same elements in exactly the same mass proportions regardless of the size or source of sample. The Law of Definite Proportions 9.5 The Laws Governing Formulas and Names

Example… The Law of Definite Proportions 9.5 The Laws Governing Formulas and Names Formula for magnesium sulfide __________MgS Ratio of Mg 2+ to S 2- ions ________1:1 Ratio of Mg 2+ to S 2- mass _______________ : For every ______ g of Mg 2+ there are always ______ g of S 2- in MgS

Example… The Law of Definite Proportions 9.5 The Laws Governing Formulas and Names If you had 100 g of MgS the mass ratio Mg:S is __________ 0.75 : 1 If you had 200 g of MgS the mass ratio Mg:S is __________ 0.75 : 1 Does MgS obey the Law of Definite Proportions? _________ Y MASS RATIO ALWAYS 0.75 : 1

Law of multiple proportions Applies to different compounds made from the same elements (e.g. NO 2 and N 2 O 4 ) Mass ratio for the same elements in different compounds can be expressed in small whole numbers. The Law of Multiple Proportions 9.5 The Laws Governing Formulas and Names

Law of multiple proportions The Law of Multiple Proportions 9.5 The Laws Governing Formulas and Names Formula for carbon monoxide __________CO Mass ratio of O to C ____________________ 16 : → 1.33 : 1 Formula for carbon dioxide __________ CO 2 Mass ratio of O to C ____________________32 : → 2.66 : 1

Law of multiple proportions The Law of Multiple Proportions 9.5 The Laws Governing Formulas and Names COCO g : 1 g O : C 2.66 g : 1 g O : C Mass ratio of C in CO to C in CO 2 ______________________________________________________ 1 g : 1 g → 1 : 1 (small whole number!!) Mass ratio of O in CO 2 to O in CO ______________________________________________________ 2.66 g : 1.33 g → 2 : 1 (small whole number!!)

Examples 9.5 The Laws Governing Formulas and Names Carbon reacts with oxygen to form two compounds. Compound A contains 2.41 g of carbon for each 3.22 g of oxygen. Compound B contains 6.71 g of carbon for each 17.9 g of oxygen. For a given mass of oxygen, what is the lowest whole number ratio of carbon in Compound A to Compound B? COMPOUND ACOMPOUND B C2.41 g6.71 g O3.22 g 17.9 g 3.22 g O in A 2.41 g C in A 17.9 g O in B 6.71 g C in B 1 g O in A 0.75 g C in A 1 g O in B 0.37 g C in B “A GIVEN MASS OF OXYGEN” 0.37 g C in B 0.75 g C in A 1 g C in B 2 g C in A LOWEST RATIO IS 2:1

Examples 9.5 The Laws Governing Formulas and Names COMPOUND ACOMPOUND B Pb2.98 g9.89 g O0.461 g g g O in A 2.98 g Pb in A g O in B 9.89 g Pb in B 1 g O in A 6.46 g Pb in A 1 g O in B g Pb in B “A GIVEN MASS OF OXYGEN” g Pb in B 6.46 g Pb in A 2 g Pb in B 1 g Pb in A LOWEST RATIO IS 1:2 Lead forms two compounds with oxygen. Compound A contains 2.98 g of lead and g of oxygen. Compound B contains 9.89 g of lead and g of oxygen. For a given mass of oxygen, what is the lowest whole number ratio of lead in Compound A to Compound B?

Daily Challenge Explain how the ending of a name determines the type of compound you have.

Chapter 9 Review Vocab –Monatomic/polyatomic –Cation/anion –Acid/base –Binary compounds (ionic/molecular) Bohr Diagrams Lewis Dot Structures Identifying charge by Group # Identifying metal/nonmetal

Chapter 9 Review Naming –When to use roman numerals –When to use prefixes Ionic vs. Molecular Difference between name endings –ide –ate –ite

Chapter 9 Review How to identify –Acid/base/neither –Molecular/ionic Laws of multiple proportions Laws of definite proportions (composition) Table (like homework) ~10 compounds Formula from name & Name from formula ~40 Draw Bohr diagrams and Lewis Dots Mass ratio problem

VocabIonsFormulasNamesMisc

VOCABULARY – 100 CONSISTS OF A GROUP OF ATOMS WITH A POSITIVE OR NEGATIVE CHARGE POLYATOMIC ION

VOCABULARY – 200 ATOM OR GROUP OF ATOMS HAVING A NEGATIVE CHARGE ANION

VOCABULARY – 300 PRODUCES A HYDROXIDE ION WHEN DISSOLVED IN WATER BASE

VOCABULARY – 400 TYPE OF COMPOUND FORMED BETWEEN A METAL AND NON-METAL IONIC

VOCABULARY – 500 TO SUBDIVIDE (AS ENERGY) INTO SMALL BUT MEASURABLE INCREMENTS QUANTIZE

IONS – 100 ALUMINUM ION Al +3

IONS – 200 SULFITE SO 3 -2

IONS – 300 AMMONIUM NH 4 +1

IONS – 400 MnO 4 -1 PERMANGANATE

IONS – 500 PHOSPHITE PO 3 -3

FORMULAS – 100 ALUMINUM HYDROXIDE Al(OH) 3

FORMULAS – 200 Diboron tetrachloride B 2 Cl 4

FORMULAS – 300 Lithium phosphate Li 3 PO 4

FORMULAS – 400 Manganese (IV) carbonate Mn(CO 3 ) 2

FORMULAS – 500 SULFUROUS ACID H 2 SO 3

COMPOUND NAMES – 100 C2H4C2H4 Dicarbon tetrahydride

COMPOUND NAMES – 200 Cu 3 PO 4 Copper (I) phosphate

COMPOUND NAMES – 300 MgN Magnesium Nitride

COMPOUND NAMES – 400 H3SH3S Hydrosulfuric Acid

COMPOUND NAMES – 500 H 3 PO 3 Phosphorous acid

MISCELLANEOUS – 100 THE LEWIS DOT STRUCTURE FOR ALUMINUM Al

MISCELLANEOUS – 200 THE BOHR DIAGRAM FOR THE FLUORINE ATOM 9 p + 2 e - 7 e -

MISCELLANEOUS – 300 THIS ARTIST HOLDS THE RECORD FOR THE BIGGEST ALL- TIME SALES FOR A SOLO ARTIST MICHAEL JACKSON

MISCELLANEOUS – 400 GROUP OF ATOMS THAT ARE THE MOST ABUNDANT AND FORM BOTH IONIC AND COVALENT BONDS NON-METALS

MISCELLANEOUS – 500 “GUILTY UNTIL PROVEN INNOCENT” IS THE STANDARD FOR THIS FEDERAL AGENCY IRS