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