2
COMPOUNDS
MOST OF THE MATTER AROUND YOU IS IN THE FORM OF COMPOUNDS.
WATER, CARBON DIOXIDE, SALT IN YOUR FOOD ARE ALL COMPOUNDS. COMPOUNDS HAVE PROPERTIES
DIFFERENT FROM THE ELEMENTS WHICH MAKE THEM UP. A GOOD EXAMPLE IS
COMPOUNDS
ELEMENTAL SYMBOLS WHEN
WRITTEN TOGETHER MAKE UP A FORMULA OR A CHEMICAL
6
COMPOUNDS
COMMON NAME: SUGAR
CHEMICAL NAME: SUCROSE
FORMULA: C12H22O11
SAND: SILICON DIOXIDE: SiO2
8
COMPOUNDS
THE CHEMICAL FORMULA FOR A
COMPOUND TELLS WHAT
ELEMENTS IT CONTAINS AND THE RATIO OF THE ATOMS OF THOSE ELEMENTS.
WHAT CAUSES ELEMENTS TO FORM
COMPOUNDS?
THE ELECTRON ARRANGMENT OF
COMPOUNDS
CHEMICALLY STABLE MEANS THAT
THE OUTERMOST ENERGY LEVEL OF AN ATOM IS COMPLETELY FILLED WITH ELECTRONS.
THE NOBLE GASES ARE THIS WAY.
THEY DON’T FORM CHEMICAL
COMPOUNDS
THE OUTERMOST ELECTRONS OR
HIGH ENERGY ELECTRONS ARE CALLED VALENCE ELECTRONS.
EACH ATOM OF ALL ELEMENTS
COMPOUNDS
ATOMS TEND TO GAIN, LOSE, OR
SHARE ELECTRONS WITH ATOMS OF OTHER ELEMENTS IN AN
ATTEMPT TO FILL THEIR
14
COMPOUNDS
SODIUM Na IS A GROUP ONE
PERIOD THREE ALKALI METAL.
Na HAS AN ATOMIC NUMBER OF 11.
COMPOUNDS
Na IS PERIOD THREE, SO IT HAS
THREE ENERGY LEVELS. THE 1ST
LEVEL CONTAINS 2 ELECTRONS. THE 2ND LEVEL CONTAINS 8
ELECTRONS. THE 3RD CONTAINS 1
ELECTRON.
IT COULD HOLD A TOTAL OF 8
16
COMPOUNDS
CHLORINE IS A GROUP 17 PERIOD
3 HALOGEN. Cl HAS AN ATOMIC NUMBER OF 17. IT HAS 17
PROTONS AND 17 ELECTRONS.
Cl HAS 2 ELECTRONS IN ITS 1ST
ENERGY LEVEL. Cl HAS 8
ELECTRONS IN ITS 2ND ENERGY
COMPOUNDS
Na HAS ONE VALENCE ELECTRON
AND NEEDS 7 TO FILL ITS
OUTERMOST LEVEL. Cl HAS 7
18
COMPOUNDS
MAGNESIUM IS A GROUP TWO
PERIOD THREE ALKALINE METAL. IT HAS AN ATOMIC NUMBER OF 12. IT HAS 12 PROTONS AND 12
ELECTRONS. IT IS ELECTRICALLY NEUTRAL.
IT HAS 2 e IN 1ST LEVEL. 8 e IN 2ND
LEVEL. IT HAS 2 e IN ITS
COMPOUNDS
OXYGEN (O) IS A GROUP 16
PERIOD 2 NONMETAL. IT HAS AN ATOMIC NUMBER OF 8. IT HAS 8 PROTONS AND 8 ELECTRONS AND IS AN ELECTRICALLY NEUTRAL
ATOM.
IT HAS 2 e IN ITS 1ST LEVEL. IT HAS
20
COMPOUNDS
Mg HAS 2 VALENCE ELECTRONS. IT
COULD HOLD 8. (O) HAS 6
VALENCE ELECTRONS. IT COULD HOLD 8. IN OTHER WORDS, IF IT TOOK THE TWO ELECTRONS FROM MAGNESIUM, IT WOULD HAVE 8
COMPOUNDS
Mg + O YIELDS MgO
Mg 12 + AND 12 -. LOSES 2
VALENCE ELECTRONS TO OXYGEN. NOW IT HAS 12 + AND 10 -. IT IS NO LONGER ELECTRICALLY
22
COMPOUNDS
OXYGEN HAS 8 + AND 8 -. IT
GAINS TWO ELECTRONS FROM Mg. NOW IT HAS 8 + AND 10 -. IT IS NO LONGER ELECTRICALLY
NEUTRAL. IT HAS A -2 CHARGE.
AN ATOM WITH A CHARGE IS
24
COMPOUNDS
THE CHARGE IS SHOWN AS A
SUPERSCRIPT.
Mg 2+ AND O
2- THE COMPOUND FORMED,
MAGNESIUM OXIDE IS
COMPOUNDS
IONIC BONDING: WHEN ONE
ATOM GAINS e AND ONE ATOM LOSES e.
COVALENT BONDING: WHEN
TWO ATOMS SHARE ELECTRONS TO COMPLETE THEIR OUTERMOST
26
COMPOUNDS
POLAR MOLECULES: UNEQUAL
COMPOUNDS
WATER H2O IS ALSO A POLAR
MOLECULE. OXYGEN ATTRACTS MORE ELECTRONS. IT IS ALSO
28
COMPOUNDS
OXIDATION NUMBER: INDICATES
THE NUMBER OF ELECTRONS LOST, GAINED, OR SHARED WHEN
COMPOUNDS
GENERAL OXIDATION NUMBERS:
ALKALI METALS: +1
ALKALINE METALS: +2
BORON GROUP: +3
CARBON GROUP: +4
NITROGEN GROUP: -3
OXYGEN GROUP: -2
HALOGENS: -1
NOBLES: 0
THE TRANSITION METALS HAVE VARIABLE
30
COMPOUNDS
COPPER AND IRON ARE TWO
TRANSITIONAL ELEMENTS THAT HAVE VARIABLE OXIDATION
NUMBERS.
COPPER Cu CAN HAVE A +1 AND A
COMPOUNDS
IRON Fe COMMONLY HAS A +2 OR
A +3 OXIDATION NUMBER. WRITTEN Fe +2 OR Fe +3
WHEN IN A COMPOUND, FOR
32
COMPOUNDS
THE ROMAN NUMERALS INDICATE
COMPOUNDS
THERE ARE TWO TYPES OF BINARY
COMPOUNDS:
BINARY SALTS: A METAL AND A
NONMETAL.
BINARY MOLECULES: TWO
34
COMPOUNDS
WHEN WRITING FORMULAS:
1) WRITE THE SYMBOL OF THE
ELEMENT WITH THE POSITIVE OXIDATION NUMBER FIRST. HYDROGEN AND ALL OF THE METALS.
2) WRITE THE SYMBOL OF THE
COMPOUNDS
3) ADD THE SUBSCRIPTS SO THAT
THE SUM OF THE OXIDATION
36
COMPOUNDS
A COMPOUND THAT CONTAINS THE
ELEMENTS ALUMINUM AND SULFUR.
1) WHAT ARE THE OXIDATION
NUMBERS?
Al IS A GROUP 13 UNDER THE
BORON GROUP. USUALLY A +3
S IS A GROUP 16 UNDER THE
COMPOUNDS
2) HOW MANY ATOMS OF EACH
ELEMENT DO YOU NEED SO THAT THE SUM OF THE OXIDATION
NUMBERS EQUALS ZERO?
WHAT IS THE LEAST COMMON
MULTIPLE OF 3 AND 2? THE +3 Al AND THE -2 S.
38
COMPOUNDS
(+3)2 PLUS 3(-2) EQUALS A PLUS 6
AND A MINUS 6 WHICH EQUALS ZERO.
WRITE ALUMINUM FIRST (IT IS A
METAL AND HAS A POSITIVE OX #)
Al
2S3
WE CALL THIS COMPOUND
COMPOUNDS
CHROMIUM Cr IS ANOTHER
TRANSITIONAL METAL WITH
VARIABLE OXIDATION NUMBERS.
Cr 2+ AND Cr 3+
WHEN NAMING COMPOUNDS WITH
ELEMENTS WITH VARIABLE OX #’S, USE THE OX # OF THE NEGATIVE
40
COMPOUNDS
NAME THE FOLLOWING: CrO
CHROMIUM (II) OXIDE
REMEMBER THAT THE ROMAN
COMPOUNDS
NOT ALL COMPOUNDS ARE BINARY.
SOME COMPOUNDS CONTAIN MORE THAN TWO ELEMENTS.
A POLYATOMIC ION IS A GROUP
OF ATOMS THAT BEHAVE AS A SINGLE ION. USE PARENTHESES
42
COMPOUNDS
NaHCO
3 IS SODIUM HYDROGEN
CARBONATE OR BAKING SODA. IT IS NOT BINARY. IT HAS FOUR
ELEMENTS. SODIUM, HYDROGEN, CARBON, AND OXYGEN.
IT ALSO CONTAINS A POLYATOMIC:
COMPOUNDS
IN THE CASE OF BAKING SODA,
NaHCO3, THE POLYATOMIC IS (CO3)2-
CARBONATE.
OTHER COMMON POLYATOMIC IONS
ARE:
SULFATE: SO
4
2- NITRATE NO
3
- PHOSPHATE PO
4
-44
COMPOUNDS
NAME THE FOLLOWING:
K
2SO4
POTASSIUM SULFATE
WRITE THE FORMULA FOR CALCIUM
NITRATE:
1) WHAT ARE THE SYMBOLS?
Ca AND NO
COMPOUNDS
2) WHAT ARE THE OXIDATION
NUMBERS?
Ca IS A GROUP TWO ALKALINE
METAL…
+2
THE POLYATOMIC NO3
46
COMPOUNDS
CALICUM NITRATE
Ca(NO
3)2
WHY ARE THERE 2 NO
3?
THE PLUS 2 OXIDATION NUMBER OF
Ca AND TWO OF THE -1 OXIDATION
PERIODIC TABLE
METALS: MOST ARE HARD AND
SHINY. MOST ARE MALLEABLE,
WHICH MEANS THAT THEY CAN BE HAMMERED OR ROLLED INTO
SHEETS. MOST ARE DUCTILE, WHICH MEANS THEY CAN BE
DRAWN INTO WIRES. MOST ARE GOOD CONDUCTORS OF
PERIODIC TABLE
METALLIC BONDING: (REMEMBER
IONIC AND COVALENT).
50
PERIODIC TABLE
GROUP I ALKALI METALS:
+1 OX #, HIGHLY REACTIVE (NOT
FOUND FREE IN NATURE), LITHIUM USED FOR MANIC DEPRESSION,
SODIUM AND POTASSIUM IN OUR BODIES, FRANCIUM, THE LAST
PERIODIC TABLE
GROUP 2 ALKALINE METALS:
+2 OX #, HIGHLY REACTIVE (NOT FOUND FREE IN NATURE), RADIUM IS
RADIOACTIVE, MAGNESIUM AND
CALCIUM IMPORTANT FOR LIFE, Mg USED IN INDUSTRY. Mg FOUND IN
CHLOROPHYLL, STRONTIUM IN FIREWORKS, BERYLLIUM IN
52
PERIODIC TABLE
GROUP 3-12 TRANSITION
ELEMENTS:
MAINLY METALS, VARIABLE OX #’S,
USUALLY +1 OR +2, ALUMINUM IS MOST ABUNDANT METAL IN
PERIODIC TABLE
ORES: METALS IN THE EARTHS
PERIODIC TABLE
TRANSURANIUM ELEMENTS: ALL OF THE ELEMENTS FOLLOWING URANIUM,
ATOMIC NUMBER 92. THESE ARE THE
SYNTHETIC ELEMENTS MADE BY MAN IN A LAB.
MADE BY SMASHING ATOMS WITH
OTHER PARTICLES. BOMBARD URANIUM WITH NEUTRONS TO PRODUCE
56
PERIODIC TABLE
NONMETALS: MOST NONMETALS
ARE GASES AT ROOM TEMP. SOLID NONMETALS ARE DULL, BRITTLE, POWDERY, POOR CONDUCTORS OF HEAT AND ELECTRICITY.
NONMETALS GAIN ELECTRONS FROM METALS BECOMING
PERIODIC TABLE
GROUP 18 NOBLE GASES ARE THE
ONLY GROUP OF ELEMENTS THAT ARE ALL NONMETALS.
GROUP 1 HYDROGEN. MOST
HYDROGEN ON EARTH IS FOUND IN THE COMPOUND WATER.
IT IS ONE OF MANY DIATOMIC
MOLECULES, MEANING IT
58
PERIODIC TABLE
GROUP 17 HALOGENS HAVE 7
VALENCE ELECTRONS. ONLY ONE ELECTRON IS NEEDED TO
COMPLETE ITS OUTER ENERGY
LEVEL. IF IT GAINS AN ELECTRON FROM A METAL, IT FORMS AN
PERIODIC TABLE
GROUP 18 NOBLE GASES. VERY
STABLE BECAUSE THEIR
OUTERMOSY ENERGY LEVEL IS FULL. THEY DON’T NATURALLY
PERIODIC TABLE
GROUPS 13-16 ARE MIXED
GROUPS. THEY CONTAIN METALS, NONMETALS, AND METALLOIDS.
GROUP 14 HAS FOUR VALENCE
ELECTRONS. CARBON IS A NONMETAL, SILICON AND
PERIODIC TABLE
ALLOTROPE: DIFFERENT FORMS OF
THE SAME ELEMENT HAVING DIFFERENT MOLECULAR
STRUCTURES. THE ELEMENT
CARBON HAS THE ABILITY TO BIND WITH ITSELF. ALLOWS FOR
PERIODIC TABLE
SILICON IS THE SECOND MOST
ABUNDANT ELEMENT IN THE
PERIODIC TABLE
GROUP 15 HAS 5 VALENCE
ELECTRONS. THIS GROUP TENDS TO SHARE ELECTRONS FORMING COVALENT BONDS.
NITROGEN IS A DIATOMIC
MOLECULE N2. EARTHS
70
PERIODIC TABLE
GROUP 16 CONTAINS THE ELEMENT
OXYGEN. THE MOST ABUNDANT ELEMENT IN THE EARTHS CRUST. IT IS A DIATOMIC MOLECULE. IT MAKES UP 21% OF THE EARTHS ATMOSPHERE. O3 IS OZONE THAT PROTECTS US FROM UV
CHEMICAL REACTIONS
CHEMICAL REACTION: ONE OR
MORE SUBSTANCES ARE CHANGED TO NEW SUBSTANCES. THE
74
REACTIONS
LAW OF CONSERVATION OF MASS:
IN A CHEMICAL REACTION, MATTER IS NOT CREATED OR DESTROYED, IT JUST CHANGES FORM. ATOMS ARE REARRANGED, BUT NEVER LOST OR DESTROYED.
YOU HAVE TO SHOW THIS WHEN
REACTIONS
SOLID LEAD (II) NITRATE,
DISSOLVED IN WATER, PLUS SOLID POTASSIUM IODIDE, DISSOLVED
IN WATER, PRODUCES SOLID LEAD (II) IODIDE PLUS POTASSIUM
NITRATE DISSOLVED IN WATER.
THIS IS THE LONG WAY TO
76
REACTIONS
INSTEAD, WE USE A CHEMICAL
SHORTHAND.
Pb(NO3)2 (aq) + 2Kl (aq) YIELDS
PbI2 (cr) + 2KNO3 (aq)
(aq) MEANS AQUEOUS OR
DISSOLVED IN WATER.
(cr) MEANS CRYSTALLINE OR
REACTIONS
THE LARGE NUMBERS SUCH AS
2KNO3 ARE CALLED COEFFICIENTS.
THEY TELL US HOW MANY UNITS
TAKE PART IN THE REACTION. IN OTHER WORDS, THEY HELP US
BALANCE AN EQUATION.
78
REACTIONS
A BALANCED CHEMICAL EQUATION
BALANCING MOLECULAR
EQUATIONS
TIPS:
1) MENTALLY COUNT OR ACTUALLY
TALLY HOW MANY OF EACH TYPE OF ATOM IS PRESENT ON EACH SIDE OF THE EQUATION.
2) BEGIN BY BALANCING ELEMENTS
80
BALANCING MOLECULAR
EQUATIONS
3) BALANCE OXYGEN AND
HYDROGEN LAST.
4) IF THERE IS AN ODD NUMBER OF
AN ELEMENT ON ONE SIDE AND AN EVEN NUMBER ON THE OTHER SIDE, THE ODD NUMBER WILL NEED TO BE EVENED OUT. USE A COEFFICIENT
BALANCING MOLECULAR
EQUATIONS
5) IF THERE ARE POLYATOMIC IONS
THAT REMAIN TOGETHER AS A UNIT DURING THE REACTION, COUNT
THE POLYATOMIC ION AS A UNIT.
6) WHEN TALLYING, BE SURE TO
ADJUST THE COUNT FOR EACH AND EVERY ELEMENT THAT AN ADDED
82
Balancing equations
NaOH + H2SO4 YIELDS Na2SO4 + H2O
ELEMENT BEFORE AFTER
Na 1 2
O 5 5
H 3 2
BALANCING EQUATIONS
2NaOH + H2SO4 YIELDS Na2SO4 +
H20
ELEMENT BEFORE AFTER
N 2 2
O 6 5
H 4 2
84
BALANCING EQUATIONS
2NaOH + H2SO4 YIELDS Na2SO4 +
2H20
ELEMENT BEFORE AFTER
Na 2 2
O 6 6
H 4 4
BALANCING EQUATIONS
BALANCE THE FOLLOWING:
NaCl + BeF2 -- NaF + BeCl2
AgNO3 + LiOH AgOH +LiNO3
CH4 + O2 CO2 + H20
Mg + Mn2O3 MgO + Mn
86
BALANCING MOLECULAR
EQUATIONS
AMMONIUM NITRATE REACTS WITH CALCIUM PHOSPHATE TO FORM
AMMONIUM PHOSPHATE AND CALCIUM NITRATE.
NH4NO3 + Ca3(PO4)2 YIELDS (NH4)3PO4 + Ca(NO3)2
FIRST, NOTICE THAT EACH OF THE
BALANCING MOLECULAR
EQUATIONS
NH4NO3 + Ca3(PO4)2 YIELDS (NH4)3PO4 + Ca(NO3)2
NH4 1 NH4 3
NO3 1 NO3 2
Ca 3 Ca 1
88
BALANCING MOLECULAR
EQUATIONS
1) BEGIN WITH CALCIUM, ADD A
COEFFICIENT OF 3 ON THE RIGHT
TO BALANCE THE CALCIUM.
2) DOING THIS CHANGES THE
NITRATE COUNT TO 6 ON THE
BALANCING MOLECULAR
EQUATIONS
6NH4NO3 + Ca3(PO4)2 YIELDS (NH4)3PO4 +
3Ca(NO3)2
NH4 6 NH4 3
NO3 6 NO3 6
Ca 3 Ca 3
90
BALANCING MOLECULAR
EQUATIONS
FINALLY ADD A COEFFICIENT OF 2 IN FRONT OF
AMMONIUM PHOSPHATE TO COMPLETE THE BALANCING.
6NH
4NO3 + Ca3(PO4)2 YIELDS 2(NH4)3PO4
+ 3Ca(NO3)2
NH
4 6 NH4 6
NO
3 6 NO3 6
Ca 3 Ca 3 PO
REACTIONS
CLASSIFYING CHEMICAL
REACTIONS:
1) SYNTHESIS: TWO OR MORE
SUBSTANCES COMBINE TO FORM ANOTHER SUBSTANCE.
A + B YIELDS AB
92
REACTIONS
2) DECOMPOSITION: ONE
SUBSTANCE BREAKS DOWN INTO TWO OR MORE SIMPLER
SUBSTANCES.
AB YIELDS A + B
REACTIONS
3) SINGLE REPLACEMENT: ONE
ELEMENT REPLACES ANOTHER ELEMENT IN A COMPOUND.
A + BC YIELDS AC + B
94
REACTIONS
4) DOUBLE REPLACEMENT: THE
POSITIVE ION OF ONE COMPOUND REPLACES THE POSITIVE ION OF ANOTHER COMPOUND TO FORM TWO NEW COMPOUNDS.
AB + CD YIELDS AD + CB
AgNO3 + NaCl YIELDS AgCl +
REACTIONS
IN CHEMICAL REACTIONS, ENERGY
IS EITHER RELEASED OR ABSORBED.
ENERGY CAN TAKE MANY FORMS,
USUALLY HEAT OR LIGHT, IT CAN BE IN THE FORM OF SOUND OR
96
REACTIONS
WHEN A CHEMICAL REACTION TAKES
PLACE, CHEMICAL BONDS IN THE REACTANTS MUST BE BROKEN.
TO BREAK CHEMICAL BONDS, ENERGY
MUST BE PROVIDED.
IN ORDER FOR PRODUCTS TO BE
PRODUCED, NEW BONDS MUST BE FORMED.
BOND FORMATION RELEASES
98
REACTIONS
IN SOME REACTIONS, LESS ENERGY
IS REQUIRED TO BREAK ORIGINAL BONDS THAN IS RELEASED WHEN NEW BONDS FORM. THIS IS
REFERRED TO AS AN EXOTHERMIC
REACTION.
IN EXOTHERMIC REACTIONS,
REACTIONS
IN SOME REACTIONS, MORE ENERGY
IS REQUIRED TO BREAK BONDS THAN TO FORM NEW BONDS IN A CHEMICAL REACTION. THESE ARE CALLED
ENDOTHERMIC REACTIONS.
ENERGY MUST BE PROVIDED FOR
REACTIONS
BURNING WOOD AND EXPLODING
DYNAMITE ARE EXOTHERMIC REACTIONS. THEY GIVE OFF ENERGY AS THE REACTION PROCEEDS.
REFINING ORES IN METAL MAKING
AND BAKING BREAD ARE
104
REACTIONS
CATALYST: A SUBSTANCE THAT
SPEEDS UP A CHEMICAL REACTION WITHOUT BEING USED UP OR
CHANGED DURING THE REACTION.
CATALYSTS IN THE BODY ARE
