Chapter 1

Law of Conservation
The total mass remains constant during a chemical change
Chemical reaction that illustrates Law of Conservation
Mercury + oxygen yields mercury || oxide
Solids
Form of matter characterized by rigidity; relatively incompressible and has fixed shape and volume
Ex. Metal
Liquids
Form of matter that is a relatively incompressible fluid; a liquid has a fixed volume but no fixed shape
Ex. Water
Gas
Form of matter that is an easily compressible fluid; a given quantity of gas will fit into a container of almost any size & shape
Ex. Oxygen
Physical Property
A characteristic that can be observed for a material without changing its chemical identity
Ex. Color, Size, Shape
Chemical Property
A characteristic of a material involving its chemical change
Ex. Heat combustion, reactivity, PH factor
Physical Change
A change in the form of matter but not in its chemical identity
Ex. melting an ice cube & breaking a bottle
Chemical Change
A change in which one or more kinds of matter are transformed into new matter or several kinds of new matter
Ex. Rusting of Iron & Burning of wood
Pure Substance
A sample of matter with both definite and constant composition with distinct chemical properties
Ex. Water, Diamond, Gold
Impure Substance
A substance that has been contaminated with other materials that differ in chemical composition
Elements
A substance that cannot be decomposed by any chemical reaction into simpler substances
Ex. Iodine, Magnesium, & Mercury
Compounds
A substance composed of 2 or more elements chemically combined
Ex. Water, Hydrogen Peroxide, Sodium Chloride (salt)
Mixtures
A material that can be separated by physical means into 2 or more substances
Heterogeneous Mixtures
A mixture that consists of physically distinct parts, each with different properties
Homogeneous Mixtures
A mixture that is uniform in its properties throughout given samples
Intensive Property
A physical property of a system that does not depend on the system size or the amount of material in the system
Ex. Color & Hardness
Extensive Property
A physical property of a system that is directly proportional to the amount of material in the system
Ex. Weight & Length
Chromatography
A group of similar separation techniques. Each technique depends on how fast a substance moves, in a stream of gas or liquid, past a stationary phase to which the substance is slightly attracted
Paper Chromatography
Generally used for identifying components of colored mixtures, such as M&Ms. Using paper to absorb different pigments
Column Chromatography
Used if one has a solution containing substances that need to be separated. Pour mixture through column containing powdered chalk, then add pure liquid. Substances will begin to separate
Gas Chromatography
Moving stream is a gaseous mixture of vaporized substances, along with another gas (ex. helium) which is the carrier. Stationary material is either a solid, or a liquid adhering to a solid, within a column. As gas goes through the column, different vaporized substances are attracted to the carrier.
How would Chromatography be used in a lab situation?
You could use paper Chromatography to separate M&M dye to find out its components for different colors.
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