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Understand the diverse states of matter, physical and chemical properties, and evidence of change like physical vs chemical changes. Dive into mixtures, elements, compounds, and laws governing matter transformations.
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Chapter 3 Matter – Properties and Change
Vocabulary pure substance states of matter solid liquid gas vapor plasma physical properties chemical properties extensive property intensive property physical change chemical change evidence of chemical reaction Law of Conservation of Mass mixture heterogeneous homogeneous solution alloy filtration distillation crystallization chromatography element compound Law of Definite Proportions Law of Multiple Proportions
3.1 States of Matter • Pure substance – matter with a uniform and unchanging composition • NaCl • H20 • Tap water
Solids • Definite shape • Definite volume • Particles tightly packed • Incompressible -
Liquid • Indefinite shape – • Definite volume • Can flow • Less closely packed • Can move past one another • incompressible
Gas • Indefinite shape • Indefinite volume – • Flows • Very far apart • Easily compressed • Vapor -
Plasma • Particles have electric charges • Can conduct electricity
Physical Properties • Characteristic that can be observed or measured without changing the samples composition • Color • Odor • Melting point • Boiling point • Density
Extensive properties – depends on amount of substance present • Ex: • Intensive properties – do not depend on amount of substance • Ex:
Chemical Properties • The ability of a substance to combine with or change into one or more other substances • Magic word: • Examples: • Burning • Iron rusting • Inert gasses
Physical Changes • Alters a substance without changing its composition • Ex:
Phase change – PHYSICAL CHANGE • Examples: • Boiling • Freezing • Condensing • Vaporizing • melting
Chemical Changes • One or more substances changing into new substances • Chemical reactions • New substances have different composition & properties • Decompose, explode, rust, oxidize, corrode, burn
Evidence of chemical reactions • Transfer of energy (heat/light) • Change in color • Formation of a gas (bubbles) • Formation of a precipitate (solid forms from 2 liquids)
Law of Conservation of Mass • Mass is neither created nor destroyed during a chemical reaction, it is conserved • Mass of reactants = mass of products
22.99 g of sodium with 35.45 g of chlorine, what mass of sodium chloride is produced? • In an experiment, 10.00 g of mercury (II) oxide is heated until it is converted to liquid mercury and oxygen gas. The liquid mercury has a mass of 9.26 g. What mass of oxygen was formed?
3.3 Mixtures of Matter • Mixture = combination of 2 or more pure substances in which each pure substance retains its original chemical properties • Most everyday matter occurs as mixtures
Heterogeneous mixture • Composition not uniform • Not evenly mixed • Not the same throughout • Examples:
Homogeneous mixture • Constant composition throughout • Every sample is the same
Solution – a type of homogeneous mixture • Solute • Solvent • Ex: Carbon dioxide dissolved in pop
Alloy – a homogeneous mixture of metals or of a metal and nonmetal • Examples • Brass • Steel • Gold jewelry
Separating Mixtures • PHYSICAL CHANGE • Based on the differences in physical properties of substances
Filtration – uses a porous barrier to separate a solid from a liquid
Distillation – separates 2 things with different boiling points
Crystallization – formation of pure solid particles of a substance from a solution containing the dissolved substance
Chromatography – separates the parts of a mixture based on the ability of each part to travel across the surface of another material
3.4 Elements & Compounds • Element – pure substance that cannot be separated into simpler substances • Earth = 92 natural elements • Not equally abundant
Compounds – made up of two or more elements that are chemically combined • Represented by chemical formulas • NaCl • H2O • CO2
Separating compounds – chemical process • Compounds that occur naturally are hard to separate because they are very stable
Properties of a compound are different from the properties of the elements that make it up • Hydrogen & oxygen vs. water
Law of Definite Proportions • A compound is always composed of the same elements in the same proportion by mass, regardless of size of the sample
Percent by mass = ratio of the mass of each element to the total mass of the compound
1.0 g of hydrogen reacts with 19.0 g of fluorine, what is the percent by mass of each element in the resulting compound: HF?
Law of Multiple Proportions • When different compounds are formed by a combination of the same elements, different masses of one element combine with fixed mass of the other element in a ratio of small whole numbers • CO vs CO2
What is the correct formula for sample 3? Gas Samples Sample Volume of Nitrogen (L) Volume of Oxygen (L) 1 2.00 3.02 2 1.01 1.99 3 1.98 4.99 4 1.98 1.02