Topic 1: Stoichiometric Relationships IB SL Chemistry Mrs. Page Introduction to the particulate nature of matter and chemical change

Understandings: Atoms of different elements combine in fixed ratios to form compounds, which have different properties from their component elements. Mixtures contain more than one element and/or compound that are not chemically bonded together and so retain their individual properties. Mixtures are either homogeneous or heterogeneous. Names of the changes of state—melting, freezing, vaporization (evaporation and boiling), condensation, sublimation and deposition—should be covered.

Applications and skills: Deduction of chemical equations when reactants and products are specified. Application of the state symbols (s), (l), (g) and (aq) in equations. Explanation of observable changes in physical properties and temperature during changes of state. Theory of Knowledge: Chemical equations are the “language” of chemistry. How does the use of universal languages help and hinder the pursuit of knowledge?

States of Matter SOLIDS Definite shape Definite volume Cannot be compressed Particles closely packed – attractive force btwn particles Particles vibrate NOTE: Absolute zero (0°K, -273°C) is that temperature at which there is no movement of particles. Temp. K = Temp °C

States of Matter LIQUIDS Take shape of container Definite volume Cannot be compressed Particles more loosely packed– attractive force btwn particles is weaker Particles vibrate, slide past each other and rotate

States of Matter GASES Take as much space as given No fixed volume Can be compressed Particles very loosely packed– no attraction btwn particles Particles vibrate, slide past each other and rotate quickly with high energy

State Changes Endothermic: heat energy is taken in from surroundings (to the substance) Melting Boiling Exothermic: heat is given off to surroundings (from substance) Condensation Freezing

HEATING & COOLING CURVES

HEATING & COOLING CURVES

HEATING & COOLING CURVES

Classifying Matter Pure Substance: made of one type of particle. Has distinct physical & chemical properties Elements: atoms of the same atomic number Compounds: fixed ratio, properties not same Mixtures: made of combinations of substances. Can be separated by physical means (filtering, magnets, chromatography, distillation) Homogeneous: uniform throughout Ex: salt water, milk, metal alloys (brass, steel) Heterogeneous: not uniform so properties vary throughout mixture Ex: raisin bran, trail mix, vegetable soup

IUPAC Naming International Union of Pure and Applied Chemistry Agreed naming systems for all chemical compounds Applied worldwide

TOK Language is a crucial component of communication of knowledge and meaning. Does the language of chemistry with its equations, symbols, and units promote or restrict universal understanding?

Types of Reactions Combination/Synthesis Two or more reactants combine to form a single product A + B  AB Decomposition One reactant breaks down into two or more products XY  X + Y Single Replacement One element replaces another in a compound AB + C  BC + A Double Replacement/Metathesis Two ions in a solution switch places to form insoluble substances and weak or non-electrolytes AB + CD  AD + CB HCl (aq) + NaOH (aq)  NaCl (aq) + H2O (l)

Classify the following Reactions 1.SiO 2 + Mg  Si + MgO 2.SO 2 +O 2  SO 3 3.CaCl 2 +K 3 PO 4  Ca 3 (PO 4 ) 2 + KCl 4.CO+O 2  CO 2 5.H 2 CO 3  CO 2 +H 2 O 6.CaCO 3 +HCl  H 2 CO 3 + CaCl 2 7.C 4 H 10 +O 2  H 2 0+ CO 2 8.P 4 O 10 +H 2 O  H 3 PO 4 9.Cu + HgNO 3  Cu(NO 3 ) 2 + Hg 10.NCl 3  N 2 + Cl 2 11.Ag 2 SO 4 + NH 4 I  (NH 4 ) 2 SO 4 + AgI

Common Polyatomic Ions & Acids You MUST Know Name of Polyatomic IonFormulaName of Polyatomic IonFormula AmmoniumNH 4 + Phophate (V)PO 4 3- CarbonateCO 3 2- PhosphonatePO 3 3- HydrogencarbonateHCO 3 - Sulfate (VI)SO 4 2- HydroxideOH - Sulfate (IV)SO 3 2- Nitrate (V)NO 3 - EthanedioateC 2 O 4 2- Nitrate (III)NO 2 - PeroxideO 2 2- Name of AcidFormula Hydrochloric AcidHCl Nitric (V) AcidHNO 3 Phosphoric (V) AcidH 3 PO 4 Sulfuric (VI)H 2 SO 4 Ethanoic AcidCH3COOH

Writing & Balancing Equations Review Reactants on left Products on right Arrow is read “yields” Must include state symbols (s), (l), (g), (aq) Number of each type of atom on reactants side MUST equal number of each type of atom on products side (law of conservation of matter) Remember your 7 diatomic elements Ex: Magnesium burns in oxygen to form a white powder known as magnesium oxide. Write a balanced chemical equation to represent this change.

More Balancing Write the balanced equations for the following reactions: Calcium metal and water yields a solution of calcium hydroxide and hydrogen gas Potassium hydroxide is a soluble base that can neutralize the diprotic acid sulfuric acid. The salt formed is aqueous potassium sulfate in water. Hydrochloric acid reacts with sodium hydrogencarbonate to form carbon dioxide, water, and sodium chloride Solid ammonium dichromate (NH 4 ) 2 Cr 2 O 7 decomposes into chromium (III) oxide, water vapor, and nitrogen gas.

The Atom Economy

HOMEWORK Read pp 1 – 11 with ALL Activity & Quick Questions Completed. (NOTE: You must label Activity or Quick Questions with Page Numbers) Keep these questions organized. This is part of your study tools.