Chemical Principles Exam 1

Modules 1-3. This set just contains Notes

Exponents on a Calculator

-e or e^x

example: -2 × 10^5= 2e-5

Log on a calculator

• may need to enter number first then Log.

  • example log(100)=2

Scientific Notation

• cannot be greater than 10 nor less than one

Order of Operations

PEMDAS

• Parantheses

• Exponents

• Multiplication

• Division

• Addition

• Subtraction

Percentages

• Percent (%) = /100

• “of”= x (multiplication)

• what= unknown quantity (x)

• is = =(equals)

Slope

rise/run

y2-y1/x2-x1

chemistry

study of matter and energy

matter

anything that has mass and takes up space

elements

• simplest form of matter

• has distinct physical and chemical properties

  • building blocks of the universe

• form attractions (Chemical bonds)

Chemical Bonds

• formed by atoms of different elements

• can be broken and form new bonds with different atoms

compound

chemical combination of elements that has its own set of properties and a chemical composition

• pure water always contains the same two elements with the same proportions

  • 88.8% oxygen, 11,2% hydrogen by mass

• Can only be separated through chemical reactions

Chemical composition

the given ratio by mass of each element in a compound to any other element in the compound

Elements and Compounds are defined as

Pure substances

• A substance in which all of the particles that make up the substance are of exactly the same kind

• two can physically combine to produce a mixture

Mixture

not chemically bonded

• can be separated by physical means

in an element

atoms may be single or bound but all the same type

in a compound

at least two different types of atoms bound together in a specific ratio

in a mixture:

can be made of any combination of elements and and compounds and are not bonded to one another

not chemically bonded and be separated by physical means

Heterogeneous

not uniform throughout

homogeneous

uniform throughout

• a solution

Aqueous Solution

a solution in water

Examples of Pure Substances

Elements & Compounds

• hydrogen & sodium (element)

• Table Salt Water (Compound)

Examples of Mixtures

Heterogeneous and Homogeneous Mixtures

• oil & water, chicken noodle soup (hetero)

• brass and vodka (homo)

Every substance has a definite set of

Properties

Propeties

characteristics by which something can be identified

Physical Properties

• unrelated to changes in chemical composition

  • color, conductivity, & melting point

Chemical Properties

Describes the characteristic ways that a substance can be identified

• related to how it reacts chemically with another substance

  • reactivity

Properties notes

chemists distinguish properties that are extensive or intensive

• properties of compounds are constant and different from the elements there made of.

• when matter undergoes change, the starting material is the reactant and the resulting material is the product.

Extensive Properties

Depends of the Quantity

• weight

Intensive Properties

remains unchanged regardless of the quantity

• color

• boiling point

Physical Change

does not alter the chemical composition

• boiling water changes the phase

• separating a mixture into components ( a mixture of elements and compound)

  • might be separated into pure substances but the pure substances that result are the same ones that were in the mixture to begin with,

  • no pure substances were formed by separating a mixture into its components