Unit One

Notes #1 Unit One Two Classes of Elements Periodic Table Info? What Are Stable Elements? Oxidation/Reduction Oxidation Numbers Key Elements and Examples Pgs

Draw a picture of an Atom For a chemical RXN to occur, two atoms MUST collide. Since the electrons are on the outside, then it is only the electrons that are involved !!! Electrons are either LOST OR GAINED

Two Classes of Elements What are the Two Main Classes of Elements? Metals and Nonmetals (Stair-Step)

What information doe the Periodic Table give us? Atomic Number # Protons = # of Electrons Mass Number = # P + # N Electron structure

So any Atom as no charge The atomic number tells us the number of protons (+ charges) AND the number of electrons (- charges). If you add all the charges up in an atom, they will equal ZERO. An ATOM has NO NET Charge !!!

If we start with an Atom….. And it gains electrons, what happens to its’ charge? It becomes negative And it loses electrons, what happens to its’ chare? It becomes positive. If an atom becomes + or – we call it an ION

We can only change the # of electrons If we were to try to change the number of protons, in the nucleus ….things have a tendency of going BOOM ! That is a nuclear reaction. So most chemical reactions involve the LOSS or GAIN of electrons OXIDATION = Loss of electrons REDUCTION = Gain of electrons

What Makes Elements Stable? Eight Electrons…… we will see this often Noble Gases (electronically stable) He, Ne, Ar, Kr, Xe, and Rn Lose or Gain to get 8e -1 (to become stable) Do metals Lose or Gain electrons? Do nonmetals Lose or Gain electrons? (Lose) (Gain)

Oxidation Numbers All elements Lose or Gain e -1. Some have multiple loss or gain possibilities. Fe +2 Fe +3 S -2 S +4 S +6

Key Elements (99%) H +1 H -1 (99%)O -2 O -1 (Always) Li +1, Na +1, K +1, Rb +1, Cs +1, Fr +1 (Always) Be +2, Mg +2, Ca +2, Ba +2, Sr +2, Ra +2 (Always) Al +3 (with only a metal) F -1, Cl -1, Br -1, I -1 (NO 3 -1 ) ion is always +5 (SO 4 -2 ) ion is always +6

Example One Find the oxidation numbers. Al 2 S 3 Algebra is useful! Al +3  key element 2(+3) + 3(S)=0 S= -2 2(Al) + 3(S)= 0

Example Two Find the oxidation numbers. Ca(NO 3 ) 2 Algebra is useful ! Ca +2 and O -2  key elements (+2)+2(N)+6(-2)=0 (+2)+2(N)+( - 12)=0 2(N)+( - 10)=0 2(N)=10 N= +5 (Ca)+ 2(N)+0 6(O)=

Finding Oxidation #’s for Compounds H 3 PO 4 H2OH2O HNO H 2 SO Hg 2 SO Na 2 Cr 2 O H 2 CO (NH 4 ) 2 CO Ca 3 (AsO 4 ) Fe 2 (SO 4 ) Ba(ClO 4 ) Al 2 (CO 3 )

Now it is time for class work !!! A101: paper practice (Work Together) It will be due at beginning of class next time Ready Set Break !!!

So Let’s Review When we are assigning oxidation numbers: If we are dealing with a molecule and there is no charge, the sum of all the oxidation numbers will add to zero. If we are dealing with a Polyatomic ion, then the sum of all of the oxidation numbers adds up to that charge Ca 3 (PO 4 ) 2 Cr 2 O 7 -2

CA101 Assigning oxidation #’s Turn on Mac: double click on the MAC folder on the desktop. Open the Redox folder and click on the yellow, red and blue icon. Choose the top button: finding oxidation Numbers in triatomic compounds.

You will do 15 problems and show all your algebra work on CA101 !!!!! I will show you how today. If you click on KEY ELEMENTS Your resource paper is online in The program.

Please get A101 and CA 101 Stamped Today !!! Once you are done we will intro Formula Writing

Notes Two Unit One Naming Inorganic Salts Example One Example One Thinking Example Two Computer Assignment One

Naming Inorganic Salts TWO parts to the name 1) Cation 2) Anion Cation Examples Ca +2 Al +3 Fe +2 Na +1 Anion Examples Cl -1 NO 3 -1 SO 4 -2 N -3 Positive Negative

Example One Name the formula Fe 2 (CrO 4 ) 3 Step #1 Find The + Ion(s). Iron(II) Fe +2 Iron(III) Fe +3

Example One Step #2 Find The - Ion(s) Chromate CrO 4 -2

Fe 2 (CrO 4 ) 3 Fe +2 Fe +3 CrO 4 -2 Iron(II) Chromate Iron(III) Fe +2 CrO 4 -2 Iron(II) Chromate (+2) (-2) Y+=0 X=1Y=1 Fe CrO 4 X (+2) (-2) 1+=01 Fe +3 CrO 4 -2 Iron(III) Chromate (+3) (-2) Y+=0 X=2Y=3 X (+3) (-2) 3+=02 Fe 2 (CrO 4 ) 3 Example One

Al 2 (CO 3 ) 3 Al +3 CO 3 -2 Carbonate Aluminum Al +3 CO 3 -2 Aluminum Carbonate (+3) (-2) Y+=0 X=2Y=3 X (+3) (-2) 3+=02 Al 2 (CO 3 ) 3 Example Two

In class work today: Work on A102 Use you Cation/Anion Sheet Remember to fnd the charges of the ions and make sure that they add up to zero to write the formula. When you are naming a formula you always write the + ion first then the -ion

CA 102:Writing Formula CA 103: Naming Compounds NAMING IONIC COMPOUNDS LEVELs ONE AND TWO Get A102, CA 102, CA103 all stamped today. Now let’s look at some examples at how to write Formulas from a name. You need to have your Cation/Anion sheet out. Homework for tonight, read L101 Electrolysis of water Lab, we will do that next class !!!!

Writing a Formula From a Name H 3 PO 4 LiNO 3 Lithium Nitrate ( )_( )_ Li +1 NO Hydrogen Phosphate ( )_( )_ H +1 PO Ca 3 (AsO 4 ) 2 (NH 4 ) 2 CO 3 Ammonium carbonate ( )_( )_ NH 4 +1 CO Calcium Arsenate ( )_( )_ Ca +2 AsO Hg 2 SO 4 Fe(IO 4 ) 3 Iron(III) periodate ( )_( )_ Fe +3 IO Mercury(I) Sulfate ( )_( )_ Hg 2 +2 SO Na 2 Cr 2 O 7 Ba(ClO 4 ) 2 Barium Perchlorate ( )_( )_ Ba +2 ClO Sodium Dichromate ( )_( )_ Na +1 Cr 2 O Pb(SO 4 ) 2 Lead(IV) Sulfate ( )_( )_ Pb +4 SO (Cation +? ) X (Anion -? ) Y (+?) (-?) Y+=0X Lowest Whole Number Ratio If X or Y is 2 or greater... and the ion is polyatomic. Ba +2 Cr 2 O 7 -2 Hg 2 +2 Pb +4

Notes Three Unit One Standard Amounts One Gopher One Mole Formula mass Percent Composition Empirical Formula

Standard Amounts How many dollars is… A) 120 pennies? 1.2 dollars B) 2 quarters? 0.5 dollars C) 15 nickels? 0.75 dollars How many dozens is… D) 48 eggs? 4 dozen E)18 apple fritters 1.5 dozen

One Dozen You KNOW it equals 12 items What if I asked you to Go into the lab and get 12 Carbon atoms?

One Mole One mole is 6.022x items. Each element on the period table has a mass per mole. N O C 14.0g 16.0g 12.0g 6.022x atoms N O C 7.0g 4.0g 18.0g =0.50m =0.25m =1.50m How many moles are in each? =3.01x atoms =1.51x atoms =9.03x atoms ÷14.0g/m ÷16.0g/m ÷12.0g/m How many atoms are in each? x6.022x atoms/m

Calculations Bases on Chemical Formulas Formula mass (Molecular Mass or Gram-Formula Mass) Empirical Formula Percent Composition

Rounding Atomic Mass C Fe O Bi K Au Os Mg Na

Formula Mass Example One Calculate the formula mass for 1 mole of C 6 H 12 O 6. C H O 6 x 12 x 6 x 12.0 = 1.0 = 16.0 = g/mol E # Mass How many molecules of C 6 H 12 O 6 is 180.0g/mol? 6.022x molecules

Empirical Formula By definition, it is the lowest WHOLE number ratio of elements in a compound. It may or may not be the actual MOLECULAR FORMULA. But is does so the whole number ratio of elements in a compound. HO = empirical formula of Hydrogen Peroxide but H 2 O 2 is the molecular Formula

Empirical Formula Example One 3) Write the formula What is the empirical (simplest) formula containing 36.8% N, 63.2% O? X by 2 to get whole numbers 1) Calculate moles of each element. N O 36.8 g ÷ 63.2 g ÷ 14.0 = 16.0 = 2.63 mol N 3.95 mol O E Q Mass 2) Calculate the lowest ratio. (divide by small moles) N O 2.63 mol N ÷ 3.95 mol O ÷ 2.63 mol = E Moles Lowest Ratio N 2 O Mass

Percent Composition Example One Calculate the percentage composition of H 2 O. H O 2 x 1 x 1.0 = 16.0 = g/mol E # Mass 2) Divide each contribution by the total mass. 3) Add the percentages to check work. 1)Calculate the formula mass for 1 mole of H 2 O H O 2.0 ÷ 16.0 ÷ 18.0 = % 88.9% 100.% ( x 100) = 11% ( x 100) = 88.9% Answer

Empirical Formula Example Two 3) Write the formula What is the empirical (simplest) formula containing 69.58% Ba, 6.090% C, 24.32% O? X by 1 to get whole numbers 1) Calculate moles of each element. Ba C g ÷ g ÷ = = mol Ba mol C E Q Mass 2) Calculate the lowest ratio. Ba C mol ÷ mol ÷ mol = E MolesLowest Ratio BaCO 3 O24.32 g ÷16.00 = mol O O mol ÷ mol = 3.00 Mass

Percent Composition Example Two Calculate the percentage composition of Fe(ClO 4 ) 3. Cl O 3 x 12 x 35.5 = 16.0 = g/mol E # Mass 2) Divide the each contribution by the total mass. 3) Add the percentages to check work. 1)Calculate the formula mass for 1 mole of Fe(ClO 4 ) 3. Cl O ÷ ÷ = % 54.2 % 100.1% Fe 1 x55.8 = 55.8 Fe 55.8 ÷354.3 = % ( x 100) = 15.8% ( x 100) = 30.06% ( x 100) = 54.19% Answer

Formula Mass Example Three Calculate the formula mass for 1 mole of Al 2 O 3 Al O 2 x 3 x 27.0 = 16.0 = g/mol E # Mass How many molecules of Al 2 O 3 is102.0g/mol? 6.022x molecules

Formula Mass Example Two Calculate the formula mass for 1 mole of CaCO 3. Ca C O 1 x 3 x 40.1 = 12.0 = 16.0 = g/mol E # Mass How many molecules of CaCO 3 is100.1g/mol? 6.022x molecules