INORGANIC CHEMISTRY

EVERYTHING IS MADE OF ELEMENTS

ELEMENTS

• 92 NATURALLY OCCURRING

• HYDROGEN LIGHTEST

• URANIUM HEAVIEST

BIG SIX ELEMENTS

• OXYGEN

• CARBON

• HYDROGEN

• NITROGEN

• CALCIUM

• PHOSPHORUS

ATOMS

• SMALLEST PARTICLES OF ELEMENTS

• PROTONS– UNCHARGED PARTICLES

• ELECTRONS– NEGATIVELY CHARGED PARTICLES

• NEUTRONS– POSITIVELY CHARGED PARTICLES

• Protons and neutrons are in the nucleus.

• Electrons move around the nucleus.

The Study of Atoms

Figure 2.1

ATOMIC NUMBER

• NUMBER OF PROTONS IN NUCLEUS

ATOMIC MASS

• PROTONS + NEUTRONS EQUAL MASS

• ISOTOPES OF AN ELEMENT ARE ATOMS WITH DIFFERENT NUMBERS OF NEUTRONS. ISOTOPES OF OXYGEN ARE:EACH CHEMICAL ELEMENT HAS A DIFFERENT NUMBER OF PROTONS.

ISOTOPES

ELECTRONS ARE ARRANGED IN ELECTRON SHELLS

• CORRESPONDING TO DIFFERENT ENERGY LEVELS

OCTET RULE

• ATOMS ARE MOST STABLE WHEN THEIR OUTERMOST SHELLS ARE FILLED WITH 2 ELECTRONS THE FIRST FEW ELEMENTS & 8 ELECTRONS FOR THE LARGER ATOMS

CHEMICAL COMPOUNDS

CHEMICAL FORMULAS

• DESCRIBE COMPOSITION AND STRUCTURE OF ELEMENTS AND COMPOUNDS

STRUCTURAL ISOMERS

• SAME CHEMICAL FORMULA

• DIFFERENT ARRANGEMENTS

CHEMICAL EQUATIONS

• REACTANTS ON THE LEFT

• PRODUCTS ON THE RIGHT

NOBLE GASES

• INERT

• ATOMS TEND TO LOSE OR GAIN ELECTRONS TO FILL THEIR OUTER SHELLS

ATOMS FORM MOLECULES

• ATOMS COMBINE TO COMPLETE THE OUTERMOST SHELL

• THE NUMBER OF MISSING OR EXTRA ELECTRONS IN THIS SHELL IS THE VALENCE

• COMBINE IN FIXED RATIOS

• A compound contains different kinds of atoms.

• The forces holding atoms in a compound are chemical bonds.

How Atoms Form Molecules: Chemical Bonds

CHEMICAL BONDS

• IONIC

• COVALENT

• The number of protons and electrons is equal in an atom.

• Ions are atoms that have gained or lost electrons and are charged.

How Atoms Form Molecules: Chemical Bonds

Figure 2.2a

• Covalent bonds form when two atoms share one or more pairs of electrons.

Covalent Bonds

Figure 2.3a

POLAR COVALENT BONDS

• Hydrogen bonds form when a hydrogen atom covalently bonded to an O or N atom in another molecule.

Hydrogen Bonds

Figure 2.4

• Ionic bonds are attractions between ions of opposite charge. One atom loses electrons and another gains electrons.

Ionic Bonds

Figure 2.2b

• CHEMICAL REACTIONS INVOLVE THE MAKING OR BREAKING OF BONDS BETWEEN ATOMS.

• A CHANGE IN CHEMICAL ENERGY OCCURS DURING A CHEMICAL REACTION.

• ENDERGONIC REACTIONS ABSORB ENERGY.

• EXERGONIC REACTIONS RELEASE ENERGY.

CHEMICAL REACTIONS

METABOLIC CHEMICAL REACTIONS ARE REVERSIBLE

• USUALLY LITTLE FREE DIFFERENCE BETWEEN REACTANTS AND PRODUCTS

• THIS MEANS AS LONG AS EXTERNAL ENERGY IS AVAILABLE MOST REACTINS IN LIVING CELLS ARE THEORETICALLY REVERSIBLE– ALLOWS CELLS TO CONTROL RELEASE OF

FREE ENERGY– ALLOWS CELLS TO RESYNTHESIZE

BIOLOGICAL MOLECULES

• THE DIRECTION OF A REVERSIBLE REACTION WILL DEPEND ON:– THE CONCENTRATIONS OF THE

CHEMICALS– THEIR ENERGY RELATIONSHIPS – THEIR SOLUBILITY

TYPES OF CHEMICAL REACTIONS

• SYNTHESIS REACTIONS

• DECOMPOSITION REACTIONS

• EXCHANGE REACTIONS

• REVERSIBLE REACTIONS

• Occur when atoms, ions, or molecules combine to form new, larger molecules

• Anabolism is the synthesis of molecules in a cell.

Synthesis Reactions

• Occur when a molecule is split into smaller molecules, ions, or atoms.

• Catabolism is the decomposition reactions in a cell.

Decomposition Reactions

• Are part synthesis and part decomposition.

Exchange Reactions

• Can readily go in either direction.

• Each direction may need special conditions.

Reversible Reactions

REDOX REACTIONS

REDOX REACTIONS: PAIRED OXIDATION AND REDUCTION REACTIONS

• OXIDATION: LOSS OF ELECTRONS• REDUCTION: GAIN IN ELECTRONS• ORGANIC MOLECULES LOSE

HYDROGEN ATOMS RATHER THAN JUST ELECTRONS

METABOLISM

• ALL THE REACTIONS THAT OCCUR IN THE CELL

WATER

THE REASON WHY LIFE CAN SURVIVE HERE ON EARTH

PROPERTIES OF WATER

• POLAR MOLECULE

• EXCELLENT SOLVENT

• COHESIVE

• ADHESIVE

• TENDS TO MAINTAIN A STABLE TEMPERATURE

• HIGH SPECIFIC HEAT

WATER IS A POLAR MOLECULE

EACH WATER MOLECULE FORM FOR A MAXIMUM OF FOUR

HYDROGEN BONDS

• Solvent– Polar

substances dissociate, forming solutes

WATER AS A SOLVENT

WATER AND CAPILLARY ACTION

• ADHESIVE AND COHESIVE QUALITIES

• Hydrogen bonding between water molecules makes water a temperature buffer.

WATER AS A TEMPERATURE BUFFER

Figure 2.4b

HEAT OF VAPORIZATION

• IT TAKE 540 CALORIES TO CHANGE ONE GRAM OF LIQUID WATER INTO ONE GRAM OF WATER VAPOR

HEAT OF FUSION

• WATER LOSES 80 CALORIES PER GRAM AS IT TURNS TO ICE

WATER BECOMES LESS DENSE AS IT FREEZES

• REACHES MAXIMUM DENSITY AT 4 DEGREES C

• EXPANDS AGAIN AS TEMPERATURE EXPANDS

• THIS IS WHY LAKES AND POOLS FREEZE FROM SURFACE DOWN & ICE FLOATS

• ALL CHEMICAL REACTIONS IN THE CELLS AND EXTRACELLULAR FLUIDS TAKE PLACE IN SOLUTION

• H+ AND OH PARTICIPATE IN CHEMICAL REACTIONS

Water

• An acid is a substance that dissociates into one or more H+.

HCl H+ + Cl

ACIDS

Figure 2.6a

• A base is a substance that dissociates into one or more OH.

NaOH Na+ + OH

BASES

Figure 2.6b

• A salt is a substance that dissociates into cations and anions, neither of which is H+

or OH.

NaCl Na+ + Cl

SALTS

Figure 2.6c

DISSOLUTION OF SALTS

IMPORTANCE OF SALTS

• SOURCE OF MINERAL IONS• ESSENTIAL FOR:

– FLUID BALANCE– ACID-BASE BALANCE– NERVE AND MUSCLE FUNCTION– BLOOD CLOTTING– BONE FORMATION– ETC

• The amount of H+ in a solution is expressed as pH.

• pH = log[H+]

• Increasing [H+], increases acidity.

• Increasing [OH] increases alkalinity.

• Most organisms grow best between pH 6.5 and 8.5.

Acid-Base Balance

BUFFERS

• OPERATE TO MAINTAIN APPROPRIATE pH levels

• WEAK ACID, WEAK BASE AND THE SALT OF THE ACID AND BASE

SODIUM BICARBONATE-CARBONIC ACID BUFFER

SYSTEM

• COMMON BUFFERING SYSTEM

                    

Figure 2.7