unit one. notes one unit one two classes of elements periodic table info? what are stable elements?...
TRANSCRIPT
Notes One Unit One
• Two Classes of Elements
• Periodic Table Info?
• What Are Stable Elements?
• Stabilizing Sodium
• Stabilizing Oxygen
• Sodium Loses electrons to Oxygen
• Oxidation Numbers
• Key Elements and Examples
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
What Makes Elements Stable? • Eight Electrons……
• Highest S and P……
• 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)
Which orbitals?
Which Family?
Stabilizing Sodium• How many electrons does sodium have?
• 11Na
• What is Sodium’s Short-Hand Element?
• 10Ne
• How many Valence Electrons for Sodium?• 1e-1
• What is the shorthand electron configuration?
• 11Na
• Sodium loses/gain how many electrons?• 1e-1
• Na Na+1 + e-1 Oxidation or reduction?• (protons) + (electrons)=charge
[10Ne] 3s1
(+11) (-10) +1
Stabilizing Oxygen• How many electrons does oxygen have?•
8O• What is oxygen’s Short-Hand Element?•
2He• How many Valence Electrons for oxygen?• 6e-1
• What is the shorthand electron configuration?•
8O• Oxygen loses/gains how many electrons?• 2e-1
• O + 2e-1 O-2 Oxidation or reduction?• (protons) + (electrons)=charge
[2He]2s2 2p 4
(+8) (-10) -2
Sodium Loses electrons to Oxygen• Na Na+1 + e-1 (Stable Like Neon) Ox or Red?• O + 2e-1 O-2 (Stable Like Neon) Ox or Red?• How many sodium atoms are needed to satisfy
oxygen’s electron hunger?• 2e-1 means • How many oxygen atoms are needed to satisfy
sodium’s electron loss?• 2e-1 means
• Na2O
two Na
One O
High Electronegativity
Low Electronegativity
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
• (NO3-1) ion is always +5
• (SO4-2) ion is always +6
Example One• Find the oxidation numbers.• Al2S3
• 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(NO3)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)+ 06(O)=
Finding Oxidation #’s for Compounds
+1 -2
+1+5 -2HH33POPO44
H2O
HNO3
+1+5 -2
H2SO4
+1 -2+6
Hg2SO4
+6+1 -2
Na2Cr2O7
+1 +6 -2
H2CO3
+1 -2+4
(NH4)2CO3
-3 +1+4 -2
Ca3(AsO4)2
+2 +5 -2
Fe2(SO4)3
+6+3 -2
Ba(ClO4)2
+2 +7 -2
Al2(CO3)3
+3 +4 -2
Now it is time for class work !!!
• A101: paper practice (Work Together)
• CA101 : computer assignment
• Both will be due at beginning of class next time
• Ready Set Break !!!
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
• NO3-1
• SO4-2
• N-3
PositiveNegative
Fe2(CrO4)3 Fe+2 Fe+3 CrO4-2Iron(II) ChromateIron(III)
Fe+2 CrO4-2
Iron(II) Chromate
(+2) (-2)Y+ = 0
X=1 Y=1
FeCrO4
X
(+2) (-2)1+ = 01
Fe+3 CrO4-2
Iron(III) Chromate
(+3) (-2)Y+ = 0
X=2 Y=3
X
(+3) (-2)3+ = 02
Fe2(CrO4)3
Example One
Al2(CO3)3 Al+3 CO3-2 CarbonateAluminum
Al+3 CO3-2
Aluminum Carbonate
(+3) (-2)Y+ = 0
X=2 Y=3
X
(+3) (-2)3+ = 02
Al2(CO3)3
Example Two
Writing a Formula From a Name
HH33POPO44
LiNOLiNO33Lithium NitrateLithium Nitrate ( )_( )_LiLi+1+1 NONO33
-1-11111
Hydrogen PhosphateHydrogen Phosphate ( )_( )_HH+1+1 POPO44-3-3
1133
CaCa33(AsO(AsO44))22
(NH(NH44))22COCO33Ammonium carbonateAmmonium carbonate ( )_( )_NHNH44
+1+1 COCO33-2-2
1122
Calcium ArsenateCalcium Arsenate ( )_( )_CaCa+2+2 AsOAsO44-3-3
2233
HgHg22SOSO44
Fe(IOFe(IO44))33Iron(III) periodateIron(III) periodate ( )_( )_FeFe+3+3 IOIO44
-1-13311
Mercury(I) SulfateMercury(I) Sulfate ( )_( )_HgHg22+2+2 SOSO44
-2-22222
NaNa22CrCr22OO77
Ba(ClOBa(ClO44))22Barium PerchlorateBarium Perchlorate ( )_( )_BaBa+2+2 ClOClO44
-1-12211
Sodium DichromateSodium Dichromate ( )_( )_NaNa+1+1 CrCr22OO77-2-2
1122
Pb(SOPb(SO44))22Lead(IV) SulfateLead(IV) Sulfate ( )_( )_PbPb+4+4 SOSO44
-2-24422
(Cation+?)X(Anion-?)Y(+?) (-?)Y+ = 0X
Lowest Whole Number Ratio
If X or Y is 2 or greater...
and the ion is polyatomic.
BaBa+2 +2 CrCr22OO77-2 -2 HgHg22
+2 +2 PbPb+4+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 Gopher• One Gopher equals 12
items
• What is the mass of one gopher of…
• A) white beads?
• 2.81g/G
• B) blue beads?
• 0.50g/G
• C) orange Beads?
• 1.67g/G
One Gopher(12 items)• In Six groups
• (1) How many gophers of beads are in…(2) How many beads are in…A) ___gB) ___gC) ___gD) ___gE) ___gF) ___g
2.00
3.49
2.51
3.75
1.75
5.82
4.00G
1.24G
1.50G
2.25G
3.50G
2.07G
48 beads
15 beads
18 beads
27 beads
42 beads
25 beads
One Mole• One mole is 6.022x10+23 items.• Each element on the period table has
a mass per mole.
NOC
14.0g16.0g12.0g
6.022x10+23atoms6.022x10+23atoms6.022x10+23atoms
N
O
C
7.0g
4.0g
18.0g
=0.50m
=0.25m
=1.50m
• How many moles are in each?
=3.01x10+23atoms
=1.51x10+23atoms
=9.03x10+23atoms
÷14.0g/m
÷16.0g/m
÷12.0g/m
• How many atoms are in each?
x6.022x10+23atoms/m
x6.022x10+23atoms/m
x6.022x10+23atoms/m
Calculations Bases on Chemical Formulas
•Formula mass (Molecular Mass or Gram-Formula Mass)•Empirical Formula•Percent Composition
Rounding Atomic Mass
CFeO
12.01155.84715.9994
BiKAu
208.98083739.0983196.96654
OsMgNa
190.2324.305022.98968
12.055.816.0209.039.1197.0190.224.323.0
Formula Mass Example OneCalculate the formula mass for 1 mole of C6H12O6.
CHO
6 x12 x6 x
12.0 = 1.0 =16.0 =
72.012.096.0
180.0g/mol
E # Mass
How many molecules of C6H12O6 is 180.0g/mol?
6.022x10+23 molecules
12.0111.007915.9994
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.
NO
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.
NO
2.63 mol N ÷3.95 mol O ÷
2.63 mol =2.63 mol =
1.00 1.50
E Moles Lowest Ratio
N2O3
14.006715.9994
Mass
Percent Composition Example OneCalculate the percentage composition of H2O.
HO
2 x1 x
1.0 =16.0 =
2.0 16.018.0g/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 H2O
HO
2.0 ÷16.0 ÷
18.0 =18.0 =
0.11 0.889
11% 88.9%100.%
1.007915.9994
( 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.
BaC
69.58 g ÷6.090 g ÷
137.33 =12.01 =
0.50666 mol Ba 0.50708 mol C
E Q Mass
2) Calculate the lowest ratio.
BaC
0.50666 mol ÷0.50708 mol ÷
0.50666 mol =0.50666 mol =
1.000 1.001
E Moles Lowest Ratio
BaCO3
O 24.32 g ÷ 16.00 = 1.520 mol O
O 1.520 mol ÷ 0.50666 mol = 3.00
Mass
Percent Composition Example TwoCalculate the percentage composition of Fe(ClO4)3.
ClO
3 x12 x
35.5 =16.0 =
106.5 192.0
354.3g/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(ClO4)3.
ClO
106.5 ÷192.0 ÷
354.3 =354.3 =
0.30060.5419
30.1 % 54.2 %100.1%
Fe 1 x 55.8 = 55.8
Fe 55.8 ÷ 354.3 = 0.1575
15.8 %
55.84735.45315.9994
( x 100) = 15.8%( x 100) = 30.06%( x 100) = 54.19%
Answer
Formula Mass Example ThreeCalculate the formula mass for 1 mole of Al2O3
AlO
2 x3 x
27.0 =16.0 =
54.0 48.0102.0g/mol
E # Mass
How many molecules of Al2O3 is102.0g/mol?
6.022x10+23 molecules
26.9815415.9994