Download Unit 1 - Measurement Atomic Theory

CHEMISTRY II AP : Unit I – Chemical Fundamentals
I) CHEMICAL FUNDAMENTALS
A) Measurement
1) Metric System
(a) Standard Units
(i) Length – meters (m)
(ii) Temperature – Kelvin (K)
(iii) Luminescence – candela (cd)
(iv) Quantity – mole (mol)
(v) Time – second (s)
(vi) Current – Amperes (A)
(vii) Mass – kilograms (kg)
(b) Coversions
(i) Use dimensional analysis and conversion factors

i.e. covert 56.0cm to inches; 2.54 cm = 1 inch

56.0 cm
=
22.1 in
2) Uncertainty in measurements – significant figures
(a) For any measurement there is a degree of uncertainty
(i) Depends upon the instrument of measure
(ii) All graduated digits are used – PLUS 1 more digit of uncertainty

The last digit is dependent on the experimenter
(iii) For any measurement the proper sig figs can always be expressed as scientific
notation
(b) Operations using Significant Figures
(i) Addition and Subtraction

The number of DECIMAL PLACES in the result is the same as the fewest
DECIMAL PLACED of any of the values used.

i.e.
12.56 + 1.9587 – 3 = 12 (no decimal places in “3” is fewest)
(ii) Multiplication and Division

The number of SIG FIGS in the result is the same as the fewest SIG FIGS
of any values used

i.e.
(3.1415926) (1.035) 2 = 3.365
(iii) Constants in equations & word numbers are exact and don’t determine SIG FIGS
B) Types of Matter
1)
DEF: Matter – anything which occupies space
2)
Elements
(a) Cannot be broken down into two or more pure substances
3)
Compounds
CHEMISTRY II AP : Unit I – Chemical Fundamentals
(a) Pure substance that contains more than one element
4)
Mixtures
(a) A combination of two or more pure substances which retain their chemical identity
(b) Homogeneous
(i) Uniform mixture
(ii) Solution
(iii) i.e. Salt water, bronze, air
(c) Heterogeneous
(i) Non-uniform mixture
(ii) Composition varies throughout
(d) Separation Techniques
(i) Filtration

Used to separate a insoluble solid from a liquid
(ii) Distillation

Used to separate a mixture of liquids
(iii) Chromatography

Used to separate
(iv) Crystallization

Used to separate a solid from a supersaturated solution
C) Properties of Subtances
1)
Intensive properties
(a) used to identify a substance
(b) Independent of the amount of matter
2)
Extensive properties
(a) Cannot identify a substance
(b) Dependent on the amount of matter
3)
Physical Properties
(a) DENSITY
(i) the ratio of mass to volume of a substance
(ii) D = M/V
for solids and liquids g/cm3 or g/mL; for gases g/L
(iii) Ways to measure mass

Direct – put it on a scale

Indirect – weighing by difference
 Measure contain; measure container & substance; use difference
(iv) Ways to measure volume

Regular solids – measure l,w,h or r,h; calculate

Liquid – measure using instrument (cylinder, beaker, buret, flask, etc.)

Irregular solids – use displacement method
(b) SOLUBILITY
CHEMISTRY II AP : Unit I – Chemical Fundamentals
(i) Can be both a chemical and physical property

Covalent compounds – physical

Ionic compounds – chemical
(ii) Expressed as grams solute/100g solvent

This described a saturated solution
(iii) Higher concentrations are supersaturated, lower are unsaturated
(c) COLOR – ABSORPTION SPECTRUM
(i) Substance must absorb in the visible range (400 – 700 nm)
(ii) Color comes from visible light NOT absorbed.
(d) OTHER PROPERTIES:
(i) Boiling Point, Melting Point, Malleability, Ductility, Specific Gravity, luster, vapor
pressure, etc.
CHEMISTRY II AP : Unit I – Chemical Fundamentals
(ii)
II)
Atomic Theory
A) Dalton’s Atomic Theory
1) An element is composed of tiny particle called atoms
2) All atoms of the same element show the same chemical properties. All the atoms of
different elements have different chemical properties
3) In an ordinary chemical reactions, atoms can only be combined, separated, or
rearranged. (Mass, charge and energy are conserved)
4) The relative ratio of atoms in any compound are definite and constant
B) Components of the atom
DEF: An atom is the smallest particle of an element that can
enter into a chemical reaction.
1) Electrons
(a) JJ Thompson – 1897
(b) Cathode Ray Experiment
2) Protons and Neutrons
(a) Ernest Rutherford – 1911 – nucleus
(b) Gold Foil Experiment
(c) Volume ratio of atom:nucleus = 10,000:1
3) Atomic Number
(a) Number of protons in the nucleus (also electrons in neutral atom)
4) Mass Number
(a) Number of nucleons in the nucleus (proton and neutrons)
(b) No. of neutrons = Mass No. – Atomic No.
(c) Isotopes
(i) Atoms which have the same atomic number and different mass numbers
(ii) Nuclear Symbol:
5) Nuclear Stability
(a) The greater the number of protons in a nucleus, the higher the ratio of neutrons:
protons needed for nuclear stability.
(b) If Z<20, Neutrons : Protons = 1, increases to 1.5 with Z=82.
(c) See Graph in Zumdahl, pp 1023.
(d) Particles from decay

Alpha, α, same as

Beta, β, same as
.
 Gamma, γ, photon – no mass
 Neutron,
CHEMISTRY II AP : Unit I – Chemical Fundamentals
C) Periodic Table - I
1)
Periods and groups
(a) Periods – rows of the periodic table
(b) Groups – Columns, have similar chemical properties
(i) Alkali metals (1) – most reactive metals
(ii) Alkaline earth metals (2) – reactive, found in earths crust
(iii) Halogens (17) – most reactive non-metals
(iv) Noble Gases (18) – non-reactive elements
(c) Other classifications
(i) Metals – left side
(ii) Metalloids – diagonal from 13 – 18
(iii) Non-metals – right side
D) Molecules and Ions
1) Molecules
(a) Combination of usually one or more non-metal atoms
(b) Held together by covalent bonding
(c) Intramolecular forces are strong; intermolecular forces are weak
(d) Structural formulas
2) Ions
(a) Formed from the loss or gain of an electron from an atom
(b) Positive – cation; Negative – anion
(c) Polyatomic ions are like charged molecules
(d) Held together by strong ionic intermolecular bonds (electrostatic)
(e) Are strong electrolytes
(f) Formula units are structure where cation charges = anion charges
(i) Anions and Cation take on noble gas configuration
CHEMISTRY II AP : Unit I – Chemical Fundamentals
III) Nomenclature
A) Main Group Ionic Compounds
1) Name Cation , then Anion
2) Know Polyatomic Ions
(a) Ions with 3-O’s are –ate, except P, S, and Cr
(b) 1 less O is –ite; 1 more is per……ate, 2 O’s less is hypo……..ite
B) Transition Metal Ionic Compounds
1) Name Cation, then roman numeral, then Anion
2) Roman Numeral is the oxidation state of transition metal
C) Molecules – Nonmetal/Nonmetal compounds
1) Use prefixes to depict the number of each element
2) Mono prefix is optional with the first nonmetal
3) Last nonmetal ending is –ide
D) Complex Ion Nomenclature
1) Anionic ligands change ending to –o
2)
IV) Electronic Structure and the Periodic Table
A) Light, Photon Energy, Atomic Spectra
1) Properties