Chapter 1 Flashcards
What is chemistry?
the study of matter, its properties, and the changes it undergoes.
Deifine Matter
Anything that has mass and takes up space
Two classifications of matter
State, composition
Three states of matter for water
Ice, liquid vapor, water vapor
Homogeneous mixture
Uniform, variable composition
heterogeneous mixture
Not uniform throughout
Element vs Cpd.
A cpd. contains more than one type of atom, element is pure
What is a substance?
Has distinct properties, composition does not vary from sample to sample
Two types of substances
Element, Cpd.
Can elements and cps. bc decomposed more?
Elements cannot be decomposed more, a compound can be decomposed into elements
What is the building block of matter?
Atom
What are elements made out of?
Unique kinds of atoms
What are cpds. made out of?
atoms from two or more different elements
How many elements are currently named?
118
How many elements make up 90% of the earth’s crust? What are they? (Largest to smallest %)
5, O, Si, Al, Fe, Ca
How many elements make up body’s mass? What are they? (Largest to smallest %)
3, O, C, H
What does the Law of Constant Composition state (AKA Law of Definite Proportions)
Cpds. have a definite composition. Means that the relative # of atoms of each element in cpd is the same in any sample
T/F Homogeneous mixtures and solutions are the same thing
True, A homogeneous mixture is also called a solution
Two types of properties
Physical, Chemical
What are some examples of physical properties?
Color, odor, density, melting point, boiling point, hardness. Physical properties DO NOT change a substance into another substance
Examples of chemical properties
Combustion & Oxidation. Chemical properties can ONLY be observed when a substance is changed into another substance
Difference btwn intensive properties and extensive properties.
Intensive prop. are independent of the amount of the substance present, while extensive prop. depend upon the amount of the substance present
Examples of intensive properties? What are they used for?
density, boiling point, color. Used for identifying a substance
Examples of extensive properites
Mass, Volume, energy
Physical vs chemical changes
Physical changes do not change composition, while chem changes do and result in new substances
Examples of physical change
State change, temperature, volume
Chemical changes
Combustion, oxidation, decomposition
Some methods for separating mixtures
filtration, distillation, chromatography
Describe filtration
Solid substances are separated from liquids and solutions
Describe distillation
Uses difference in boiling points of subs to separate of homogeneous mixture into is components
Define energy
The capacity to do work or transfer heat
Define work
Energy transferred when a force exerted on an object causes a displacement of that object
Heat
Energy used to cause the temperature of an object to increase
Force
Any push/pull on an object
Define kinetic energy & formula
Energy of motion;
KE=(1/2)mv^2
Define potential energy
Energy that depends upon an object’s relative position compared to other objects
Qualitative vs quantitiave
Relative characterization vs numerical characterization
SI base unit for mass?
kilogram
Metric system base unit for mass
Gram
Base unit for length
Meter
Freezing and Boiling points in celsius
0 and 100
What is the base temp. unit for properties of gases
Kelvin
Celsius to Kelvin equation
K=C+273.15
F to C temperature equation
F=(9/5)(C)+32
C to F temperatuer equations
C=(5/9)(F-32)
Common units for density
g/cm^3 or g/mL
