Honors Chemistry Exam 2 Ch 1-8 TERMS

evaporation and filtration

A mixture is made up of two or more substances physically combined, and can be separated by physical separation techniques such as

Homogeneous

Pure substances are homogeneous

Uniform throughout, such as with solutions like salt water or soda

Heterogeneous

Not uniform throughout such as salt and pepper or dirt

Element or compound

Pure substance

Fixed composition

The elements that make up a compound are in a what?

1:2

Fixed ratio of CO2

Protons, neutrons, and electrons

The atom has what three subatomic particles

In the nucleus

Where are protons and neutrons located?

Outside the nucleus

Where are electrons located?

Positive

charge of a proton

Neutral

Charge of a neutron

Negative

Charge of a electron

Protons

Which subatomic particle identifies the element

By the atomic numbers of the element

Each element has a different atomic number

How are protons represented?

Isotopes of an element

have the same number of protons but different numbers of neutrons

Protons plus neutrons

Equals the mass number of an element

Electrons

The gain or loss of this subatomic particle by an element forms an ion

Ion

A charged atom

kilo, hecto, deka, base unit, deci, centi, milli

Good to know

Carbon tetrachloride

CCl4

A molecular formula (nonmetal +nonmetal)

dinitrogen pentoxide

N2O5

A molecular formula

Co2

carbon dioxide

Formula for molecular compounds

B2O3

diboron trioxide

Formula for molecular compounds

SO4^2-

Sulfate

NO3^-1

Nitrate

PO4^3-

Phosphate

Sodium Nitrate

NaNO3

Formula for ionic compounds

Aluminum chloride

AlCl3

Formula for ionic compounds

Empirical formula

is the lowest ratio of atoms

Ideal gas

Is a gas that obeys exactly the assumptions of the kinetic molecular theory

1. Gas molecules are in constant, rapid, random motion.

2. Gas molecules undergo elastic collisions.(no energy is lost when they collide.)

3. The kinetic energy of gas molecules is directly related to temperature.

4. Gas molecules are very far apart and are negligible in volume compared to the volume of the gas.

5. Gas molecules have negligible attraction between them.

Five assumptions are the kinetic molecular theory

V1P1=V2P2

Boyle's law formula

V1/T1=V2/T2

Charles law formula

V1P1/T1=V2P2/T2

Combined Gas Law Formula

Directly proportional

The relationship between temperature(in Kelvin) and volume

Indirectly proportional

The relationship between pressure and volume when temperature is held constant

0 Kelvin and -273.15 degrees Celsius

Absolute zero equals what?

PV= nRT

ideal gas law equation

P= Pressure

V= volume

n= number of moles

R= universal gas constant

T= temperature

What does each variable in PV=nRT stand for?

Graham's law of diffusion

Lighter gases diffuse faster than heavier gases

The diffusion rate of any gas is inversely proportional to the square root of the gas' molar mass

P total=P1+P2+P3...

Dalton's Law of Partial Pressure equation

22.4 L

What is the molar volume of any gas at conditions of STP (standard temperature and pressure)

First law of thermodynamics

The energy gained(or lost) by a system equals the energy lost(or gained) by the surroundings

Internal energy (E)

Measured by the change in internal energy and represented by the formula: Delta E=Q+W in a closed system

Heat(Q)

Transfer of energy as a result of a temperature difference

Work(W)

Transfer of energy through a force applied across a distance

Joule

SI unit of energy

Enthalpy(H)

Enthalpy = the internal energy of a system + the product of the pressure and volume

Is measured by the change in Enthalpy

Means the heat within

Endothermic reaction

Is positive

Delta H

More heat within the products

Some chemical reactions absorb energy into the reacting substances and store in the chemical bonds of the products

Exothermic reaction

Negative number

Delta H

Less heat within the product

Heat can be considered a product, it is released. The reaction vessel feels hot.

Some chemical reactions release energy that was stored in the chemical bonds of the reactants

Enthalpy of formation (DeltaH)

The total energy released or absorbed between the start of reaction and its end

Enthalpy of formation

At its standard state of 25 Celsius and one atmosphere. It is called the standard Enthalpy of formation.

Is equal to heat

Can be expressed as KJ per mole of substance formed from its elements

CH2O

What is the empirical formula of C6H12O6

specific heat (c)

The heat required to cause a unit rise in the temperature of a unit mass of a substance

Heat of fusion or enthalpy of fusion

The energy(heat) per unit mass to melt a substance at its melting point

Negative

The sign of free energy change for spontaneous reaction is what

Free energy= Change in enthalpy-the product of temperature and change in entropy

Gibbs free energy equation

Spontaneous

If a chemical reaction is exothermic(negative enthalpy) and has an increase in disorder(positive entropy) the reaction is what?

Crest

Highest point of a wave

Trough

Lowest point of a wave

wavelength

The distance between any two corresponding points on successive waves

Amplitude

The height of a wave, equal to half the distance between the crest and trough

Strength

Amplitude measures a waves what?

Frequency

The number of complete waves(crest+ trough) that passed by a point in a given time is a measure of the waves what

Hertz

SI unit for frequency

3.00×10^8 m/s

Determined by James Maxwell, the speed of a wave is calculated to be what

The wave theory of light was proposed by Christian Huygens and expounded upon by James Maxwell

Good to know

Electromagnetic wave

Maxwell described light as what

Electromagnetic spectrum

An arrangement of all forms of electromagnetic radiation in order of frequency and wavelength

Inverse relationship

Ex. If wavelength decreases, frequency increases.

The relationship between frequency and wavelength

Max Plank

The particle theory of light was first proposed by Isaac Newton, and expounded upon by who

Quantum theory of light

Max plank developed what theory where light is made up of photons

Photons

Individual packets or quanta of light energy

Quanta

Plank said that energy could only be admitted or absorbed in discrete units called what

Wave particle duality

Thus the quantum theory of light allows us to define light as electromagnetic waves traveling as protons

Einstein expanded on Maxwell's Wave theory and planks particle theory of light said that light can behave as both a particle and a wave

Spectrometer

Used to observe line spectra of elements that is produced when the element is vaporized and heated

In this case, the electrons of the element are exited to a higher energy level, and then when they return to ground state, they emit a photon of energy

Erwin Schrodinger

Developed the wave mechanical model, which could account for the many align spectra of atoms having multiple electrons

Principal quantum number

Describe the energy level in which an electron is located

Subshell quantum number

Describes the shape of the subshell

s, p, d, f

Magnetic quantum number

Describe the orientation of the subshell in space

Spin quantum number

Describes the spin of the electron, clockwise or counterclockwise

Electron configuration

the arrangement of electrons in an atom

Quantum numbers

Are used to determine the electron configuration

Pauli Exclusion Principle

Different spins make the fourth quantum number different

No two electrons have the same four quantum numbers

Aufbau Principle

States that electrons fill the lowest energy level orbitals first

Hund's Rule

States that a single electron occupies each orbital within a subshell before electron pairing begins

Spherical

It only has one orientation in space or one orbital

Shape of the S subshell

Three p orbitals

The P subshell has how many orbitals

Five

How many orbitals does the D subshell have?

Seven

How many orbitals does the F subshell have?

Two

The maximum amount of electrons for each orbital

Valence electrons

Outer most electrons in an atom which are involved in chemical reactions

Lewis symbol or electron dot formula of an atom

Is used to show the number and arrangement of the valence electrons

s and p orbitals

Where valence electrons are found

Eight

Maximum number of valence electrons an element can have

Dimitri Mendeleev

Created the periodic table

Group

A column on the periodic table

Period

A row on the periodic table

Alkaline metals

+1 charge

Group I

Alkali earth metals

2+ charge

Group II