General Chemistry Chapter E and Chapter 1 and chapter 2

Qualitative observations

Descriptive in nature; changers in color and physical state

Quantitative observations

measurements, numerical values from instrumentation, glassware and other measuring devices, varying precision and accuracy; counted values

Quantitative measurement errors

systematic or determinate errors; error is in the same direction; either higher or lower than should be

Random or indeterminate error

Equal probability of measure being lower or higher than should be; difficult to correct or find source

giga(G)

10^9

mega(M)

10^6

kilo(k)

10³

deci(d)

10^-1

centi( c )

10^-2

milli(m)

10^-3

micro(μ)

10^-6

nano(n)

10^-9

pico(p)

10^-12

C + 273.15K

to find K(kelvin); what is the equation?

1000ml, 1000cm³; 1ml=1cm³

1L can equal?

dollars($), inches, feet, centimeters

what conversion factors have an inf. # of sig figs?

All nonzero factors are significant(ex: 5462)

zeroes between nonzero digits are significant (i.e. 5701)

Leading Zeroes are not significant (i.e. 0.0043[2 sig figs])

Trailing zeroes WITHOUT a decimal point are NOT significant (i.e. 7000 is [one sig fig])

What are the significant figure rules?

Precision

agreement or closeness of a series of measured values (can be precise but not accurate)

Accuracy

Agreement or closeness of measured value to actual known value

Uncertainty

The uncertain digit depends on the instrument being used; reported typically as a plus or minus(±). 23.45 ± 0.05mL, indicates the last digit of the measured value

Go by the least precise measured value. (ex: 3.56cm times 4cm=14.24cm; actually is 10cm² due to only one sig fig)

How do you calculate sig figs with multiplication and division?

The values with the smallest decimal measurement determines the answers sig figs (ex: 23.467+ 313.21=336.677; answer with sig figs is 336.67 due to 313.21 having 2 sig figs after the decimal point)

How do you calculate sig figs with addition and subtraction?

Density

mass/volume

Intensive physical property

Intensive physical properties are independent of amount of substance being measured (ex: boiling point); it happens no matter what.

Extensive physical properties

the physical properties of mass and volume that determine a substances density; (ex: densities of liquids and gases are affected by temperature)

When given a word problem; look at the last given known and cancel units from there

What is the Dr. Aitkens way of solving a problem of unit cancellation?

Energy

capacity to do work

work

the action of a force applied through a distance

Force

A push or pull on an object

Kinetic Energy

energy associated with movement; ½ mv²

potential energy

energy associated w/ position (i.e. a boulder being dropped from a high building has high potential energy)

calorie(cal)

The amount of heat needed to raise the temperature of 1 gram of water by 1 celsius degree (1000cal=1Kcal=1Cal)

4.184J

How many joules equal a calorie?

Exothermic heat

system loses heat, heat goes to the surroundings; energy of the system decreases, energy of surroundings increase. Heat is negative (-) here.

Endothermic

system gains heat from surroundings; energy of system increases; energy of surrounding decreases. heat is positive (+) here.

Atoms

Basic submicroscopic particles that constitute the fundamental building blocks of matter

molecules

particles formed when two or more atoms bond together in specific geometric arrangements

solid matter

atoms or molecules pack closely to each other in fixed locations; fixed volume and rigid shape

Liquid matter

atoms or molecules pack about as closely as they do in solid matter, but they are more relative to each other; fixed volume, no fixed shape

Gaseous

atoms or molecules have a lot of space between them; free to move and compressible

Pure substance

made up of only one component and its composition is invariant (elements and compounds)

mixture

substance composed of two or more compounds in proportions that can vary from one sample to another

Element

a substance that cannot be chemically broken down into simpler substances; composed of a single-type atom

compound

substance composed of two or more elements in fixed, definite proportions

Heterogeneous mixture

is one in which the composition varies from one region of the mixture to another; made of multiple substances, whose presence can be seen

Homogeneous mixture

made of multiple substances, but appears to be one substance; have uniform compositions, since atoms or molecules that compose them mix uniformly. all portions have the same composition

observations

formulation of a hypothesis

experimentation

formulation of laws and theories

What is all under the scientific method?

observations

data, characteristics/behavior of nature, leads to a hypothesis

hypothesis

tentative interpretation or exploration of the observations; can be falsifiable(proven wrong)

Law of Conservation of Mass

in a reaction, matter is neither created nor destroyed

Theory

tries to explain not merely what nature does, but why a natural phenomenon happens (ex: big bang theory); they can never be conclusively proven

Law of Definite Proportions

All samples of a given compound, regardless of their source or how they were prepared, have the same proportions of their constituent elements (constant composition); A chemical compound always contains the same elements in the same ratio by mass, no matter where it comes from or how it’s made.

Law of Multiple Proportions

when two elements for two compounds (AB); when atom A combines with multiple atoms of B, molecular compounds like this (AB1, AB2, AB3) are possible

1. Each element is composed of indestructible particles called atoms

2. All atoms of a given element have the same mass and other properties that distinguish them from the atoms of other elements

3. Atoms combine in simple, whole-number ratios to form compounds

4. Atoms of one element cannot change into atoms of another element; in a reaction, atoms change the only way that they are bound together

What is Dalton’s Atomic Theory?

J.J Thompson’s Cathode Ray experiment

There is a stream of negatively charged particles that are present in all atoms; the particles in this experiment travel in straight lines, they are independent from the material they originated from

Milikans Oil Drop experiment

measured the strength of the electric field required to halt the free fall of oil drops; charge of the oil drop was always -1.60 times 10^-19 C(charge of an e-)

Rutherford Gold foil experiment

We know that an electron surrounds a positively charge nucleus; matter is not uniform as it appears, there are spaces in an atom

Protons

Neutrons

Electrons

what are atoms composed of?

the atomic number of an electron shows how many protons and electron there are (ex: if Cobalt’s atomic number is 27; there are 27 protons, and to balance this there is 27 electrons.)

when looking at the atomic number(#) of an element, what does this correlate to?

amount of protons (also the atomic #) plus the amount of neutrons; the # of neutrons can be found, by subtracting the mass # by the atomic #.

what does the mass # mean on an element?

Cations

positively charged ions(metal elements form this)

Anions

negatively charged ions(nonmetal elements)

[mass of isotope 1(amu) times percent of isotope 1 (in decimal form)] + [mass of isotope 2(amu) times percent of isotope 2] = atomic mass(found on periodic table)

How do you properly calculate atomic mass?

if you are given the percent of one isotope; then do 1 - percent of given isotope to find the other one

if you are missing a percent of an isotope, how can you find it?

mol(mole)

6.022 times 10 to the 23; the value of this is equal to the number of atoms exactly in an element; 1 mol = 6.022 X 10 to the 23 atoms

wave-particle duality

an electron has energy-like characteristics under a different set of experimental parameters

Quantum Mechanical Model

a model of how electrons exists and behaves

Light

Form of electromagnetic radiation; has an electric field and magnetic field; composed of waves and all electromagnetic waves move at the same constant speed.

speed of light

c; 3.00 times 10^8 m/s

Electromagnetic radiation

a wave comprising oscillating electric and magnetic fields that are perpendicular within planes

amplitude

height of a wave; measure of light intensity. the larger the amplitude, the brighter the light.

wavelength

also known as a lambda(λ); a measure of the distance covered by the wave; distance from one crest to another. also determines the color of the light.

λ=c/f

what is an equation to find lambda/wavelength?

it has the weird v looking symbol; but it is the number of waves that pass a point in a given period of time; # of waves= # of cycles. its units are Hz

Frequency

weird looking v = c/λ

what equation does frequency have?

h; 6.626 times 10^-34 J times S

what is planticks constant?

E=hv

what is one of the equations to find energy of a photon(E)?

Radio

microwave

infrared

visible

ultraviolet

x-ray

Gamma

what is the spectrum from low to high intensity?

electromagnetic spectrum

visible light comprises only a small fraction of all the wavelengths of light

photoelectrons (photoelectric effect)

electrons emitted from metal surface when light is shined on a metal surface

Threshold frequency

A minimum frequency was needed before electrons would be emitted regardless of the intensity

hc/λ

what else can energy of a photon(E) equal?

the smaller the wavelength, the higher the energy

What is the correspondence between wavelength and energy?

number(#) of photons= Energy of the Pulse/ Energy of the photons

what is the equation for the number of photons?

hv- energy binding or Energy of the photon - Energy of binding

what is the equation for kinetic energy?

Kgm²/s²

what is a different way to show a Joule for unit cancellation?

Quantized

using Bohrs model of an atom and its electron orbitals, the atom can only have specific amounts of energy; the energy of the atom is related to the electrons position.

De Broglie

proposed that particles have wave-like properties

h/mv; v is for velocity or speed

What is another way to find wavelength?

complimentary properties

The wave and particle nature of electron have this; the more you know about one property, the less you know about the other

Heisenbergs Uncertainty Principle

the more accurately you know the position of a small particle, the less you know about its speed. (vice-versa)

Quantum numbers(#)

calculations that show the size, shape, and orientation in space of an orbital

Energy level/shell

a “shell” around the nucleus; determines the average distance of an electron from the nucleus

Orbital

• Each energy level contains one or more orbitals, which describe the shape and region in space where an electron is likely to be found.

• Denoted by s, p, d, f (sublevels).

• Each orbital type has a specific shape:

  • s → spherical

  • p → dumbbell

  • d,f → more complex

• Each orbital can hold 2 electrons (with opposite spins).

Example:

• n=2 → has:

  • 1 × 2s orbital (spherical)

  • 3 × 2p orbitals (px, py, pz) → each can hold 2 electrons → total 8 electrons in n=2

Orbitals are like the rooms on a floor. Different shapes = different rooms.

n

principal quantum #; it determines the energy level; values of n cannot be less than 1, but can be equal to 1

l(L)

angular momentum quantum #; determines the orbitals shape and type. L can have values from 0 to (n-1)

Magnetic quantum # (mₗ)

Position of orbital in an x, y, z plot; example: if L=1,mₗ is -1,0,1. -1 is px, 0 is py, 1 is pz.

spin quantum number (mₛ)

orientation of the spin of an electron; the spin is + ½ or - ½; when writing out the number of electrons with the up and down arrows make sure you do all up arrows first 3 times then do the down arrows since it takes more energy to pair a negative and positive spin

letters, values, and shapes that pair with l(L)

s orbitals: spherical; L=0

p orbitals: two balloons tied together at their knots; L=1

d orbitals: look like a 4-leaf clover; L=2

f orbital: 8 balloons tied at their knots; L=3

look at the last number in the subshell

how do you find the # of orbitals in a subshell?