Chemistry AIChapter 2

 A. Matter ( Section 2.1)

 1. Extensive property

 a. Mass

 b. Volume

 

Property that depends on the amount of matter in an object

Measure of the amount of matter an object containsMeasure of the amount of space occupied by an object

2. Intensive propertyProperty that depends on the type of matter in an object, not the amount

 3. States

 

1. Solid-definite shape and volume; tightly packed, rigid, and orderly arranged particles; incompressible

2.Liquids- indefinite shape; definite volume; closely packed, free flowing, unorganized particles; incompressible

3.Gas- indefinite shape and volume; free flowing, unorganized particles; particles are far apart from each other; compressible

 B. Classifying Matter 

 1. Substance (Section 2.2)

 a. Element

Matter that has a uniform and definite composition Salt is a substance; Kool-aid is not

Simplest form of matter that can exist under normal conditions (ex. Hydrogen, Oxygen)

b. Compound

A substance that contains two or more elements chemically combined in a fixed proportion (ex. C12H22O11)

b. Compound Continued

Can be broken down to elements, but only by chemical means (chemical change)

A Compound may have very different properties as compared to its elements

NaCl – saltNa- sodium- very explosive metalCl- chlorine- very toxic green gas

 c. Symbols and   Formulas

2. Mixture(Section 2.3)

Used to represent elements and compounds respectively

Physical blend of two or more substancesCan be separated by decanting, filtration, distillation, etc.

 a. HeterogeneousThe composition is not uniform throughout. The mixture contains more than one phase (ex. Italian salad dressing, bag of M&M’s, oil and water)

 b. Homogeneous (Solution)

C. Identifying Matter

 1. Physical Property

 (Section 2.1)

The composition is uniform throughout. The mixture contains only one phase. (ex. Air, stainless steel, Pepsi, tap water)

A quality or condition of a substance that can be observed or measured without changing the substance’s composition (ex. color, hardness, state, melting point, smell…)

Alters a substance without changing its composition (does not change what it is made of) (ex. Change of state, cutting, tearing)

Reversible or irreversible

 2. Physical Changes

 3. Chemical Property

 (Section 2.4)

The ability of a substance to undergo a specific chemical change/ reaction and form a new substance

4. Chemical Change/  Chemical Reaction

A change of one or more substances into other substances, this involves the rearrangement of atoms (ex. Burn, rust, ferments, explodes, corrodes, etc.)

Indication of a chemical reaction include: 1. color change 2. gas production 3. energy transfer  (temperature change) 4. formation of a precipitate (solid that settles out of a liquid) 5. odor change

NaHCO3 + CH3COOH CO2 + H2O + NaC2H3O2

Does a physical change always mean that a chemical change has occurred?

The starting substances in a chemical reaction and they are often found on the left hand side of a chemical equation.

a. Reactants

The new substances that are formed in a chemical reaction and they are often found on the right hand side of a chemical equation

CH4 + 2O2 CO2 + 2H2O

(Reactants) (Products) 

b. Products

5. Law of Conservation of Mass or Matter (Antoine Lavoisier)

Mass is neither created nor destroyed during a chemical reaction; it is conserved.

Atoms are only rearranged.

The mass of the products is always equal to the mass of the reactants.