Post on 22-Dec-2015
CHAPTER 1: STOICHIOMETRI
C RELATIONSHIPS
1.1: INTRO TO PARTICULATE NATURE OF MATTER & CHEMICAL CHANGE
Some important terms: Elements
Chemical symbolAtoms
Compounds Chemical
Properties/Changes Chemical equationReactantsProducts
MixturesHeterogenousHomogenous
Kinetic theory Diffusion States of
matter/symbolsMelting/freezingEvaporation/
condensationSublimation/deposition
PURE SUBSTANCES VS MIXTURES Elements: a single atom or diatomic molecule that
cannot be broken down by chemical means Exs (chemical symbols): Ar Ga H2 Cl2 Li Compounds: 2 or more elements chemically
combined Exs: H2O CaCl2 BF3 CH3OH NH3
Mixtures: 2 or more compounds physically combined Heterogenous: non-uniform composition throughout Exs: salsa salad milk wood oil/water Homogenous uniform composition throughout Exs: kool-aid salt water air tea water/alcohol
PURE SUBSTANCES VS MIXTURES Pure substances: each sample of that
substance has the same properties or characteristics as every other sample
Mixtures: made up of several substances, each which retains their individual properties
PURE SUBSTANCES VS MIXTURES Elements: a single atom or diatomic molecule that
cannot be broken down by chemical means Exs: Ar Ga H2 Cl2 Li V Compounds: 2 or more elements chemically
combined Exs: H2O CaCl2 BF3 CH3OH NH3
Mixtures: 2 or more compounds physically combined Heterogenous: non-uniform composition throughout Exs: salsa salad milk wood oil/water Homogenous uniform composition throughout Exs: kool-aid salt water air tea water/alcohol
PURE SUBSTANCES VS MIXTURES Elements: a single atom or diatomic molecule that
cannot be broken down by chemical means Exs: Ar Ga H2 Cl2 Li V Compounds: 2 or more elements chemically
combined Exs: H2O CaCl2 BF3 CH3OH NH3
Mixtures: 2 or more compounds physically combined Heterogenous: non-uniform composition throughout Exs: salsa salad milk wood oil/water Homogenous uniform composition throughout Exs: kool-aid salt water air tea water/alcohol
Compounds Mixtures
•Elements lose their chemical characteristics
•can be separated by chemical means
•same composition by mass for a compound
•Parts retain their properties
•can be separated by physical means
•composition may vary
CLASSIFYING MATTER
E lem en ts C om p ou n d s
P u re S u b s tan ces
H om og en eou s H ete rog en eou s
M ixtu res
M atte rso lid , liq u id , g as
SEPARATING MIXTURES Mixtures can be separated by
physical meansDistillation: liquid is boiled to
produce vapor. The vapor is then condensed back into a liquid.
Magnetism: if an element has magnetic properties, it can be separated using a magnet.
Filtration: smaller particles will pass through the filter while larger ones will get stuck
Evaporation: liquid is evaporated leaving behind particles that were in liquid
CLASSIFY THE FOLLOWING AS COMPOUND OR MIXTURE? Water? Answer: compound Air? Answer: mixture Salt? Answer: compound Carbon dioxide? Answer: compound
CLASSIFY THE FOLLOWING AS HOMOGENEOUS OR HETEROGENOUS Air Answer: Homogeneous mixture Granite Answer: Heterogeneous mixture Sand and water Answer: Heterogeneous mixture
CHEMICAL CHANGES Chemical equation: Ca + O2 CaO Balanced chemical equation: 2Ca + O2 2CaO Chemical equation with state symbols: 2Ca(s) + O2(g) 2CaO(s)
State symbols: Gas = (g) Liquid = (l) Solid = (s) Aqueous (in solution with water) = (aq)
KINETIC THEORY States of matter are determined by the amount
of kinetic energy the particles have Temperature Pressure
Therefore, KT states: the average kinetic energy of the particles is directly related to the temp of the system (and thus affects P as well)
Inter-particle forces = Strength of forces between particles
KE=1/2mv2 (the larger the mass, the slower it flows)
CHANGING STATES OF MATTER