How can we help?

You can also find more resources in our Help Center.

77 terms

Honors Chem Midterm Review Sheet

STUDY
PLAY
chemistry
the study of matter and it's changes
modern world: age of _____
plastics
matter
anything that has mass and takes up space
vapor
gaseous state of a substance that is generally a liquid or a solid at room temp.
solid
particles tightly packed, defined shape and volume
liquid
expands when heated, takes shape of the container, particles are semi-flexible
gas
takes shape and volume of container, particles are far apart
scientific method
observation>hypothesis>experiment>theory
theory
braod and extensively tested explanation of why experiments give certain results. can't be proven
law
concise statement that summerizes the results of many observations and experiments. can be proven, but can't be explained
hypothesis
a proposed explanation or reason for what is observed
how to study chemistry
understand and apply concepts by using your textbook, experiments tests and quizzes
physical properties
state, color, meling point, boiling point, density
physical changes
cutting, grinding, bending, etc.
distillation
boiling liquid to produce a vapor that is then condensed again into a liquid. it purifies the liquid
homogeneous mixtures
completely uniform in composition (ex. salt water)
also called a solution
heterogeneous mixtures
not uniform in composition (ex. chocolate chip cookie)
mixture
either hetero. or homo.
a physical blend of two or more substances that is seperable by hand
compound
a substance that can be separated into simpler substances only by chemical means
qualitative
results given in a descriptive, nonnumeric form
quantitative
results given in definite numbers and units
accuracy
the measure of how close a measurement is to the actual, true value
precision
the measure of how close measurements are to one another
sigfig rule on leading zeros
they don't count ever (sigfigs)
sigfig rule on in-between zeros
they always count (sigfigs)
sigfig rule on zeros at the end
they only count if there is a decimal (sigfigs)
mega(M)
10^6
kilo(k)
10^3
deci(d)
10^-1
centi(c)
10^-2
milli(m)
10^-3
micro(μ)
10^-6
nano(n)
10^-9
pico(p)
10^-12
how to become a better problem solver
develop a plan
the heart of problem solving
analyze>calculate>evaluate
density (equation)
m/v
relationship b/w numerator and denominator in a conversion factor
numerator is equivalent to denominator
smallest particle of an element that retains all its properties
atom
Democritus
first suggested the idea of atoms
Dalton's Atomic Theory
•invisible particles
•atoms of same element are identicle
•atoms of different elements can physically mix together in simple whole-number ratios
•atoms of 1 element are never changed into atoms of another element as a result of a chemical reaction
JJ Thompson
discovered the electron
Robert A. Millikan
discovered the quantity carried by electron
E. Goldstein
discovered protons
James Chadwick
discovered neutrons
Ernest Rutherford
discovered the nucleous
Rutherford Experiment
Gold foil method**
nucleus
center of an atom, heaviest part, made up of protons and electrons
electron
negatively charged, form a cloud around the nucleus
proton
positively charged
neutron
no charge at all
atomic number
•the number over the chemical symbol of the periodic table
•tells how many protons are in the element
mass number
•the sum of the number of neutrons and protons in an atomic nucleus
•under the chemical symbol
finding isotopes
different number of neutrons=different number of mass
(ex. Ne-20: 10p, 10n, 10e; Ne-21: 10p, 11n, 10e; Ne-22: 10p, 12n, 10e)
isotopes
atoms that have the same number of protons but a different number of neutrons
how to find the atomic mass of a series of isotopes
average the masses
anion
ions that end in "-ide"
the electrical charge of a cation
positive charge
cation
any atom or group of atoms that has a positive charge, meaning one or more electron has been taken away
⁺sign is directly after the chemical symbol
anion
any atom or group of atoms that has a negative charge, meaning one or more electrom has been added
⁻sign is directly after the chemical symbol
ionic compounds
composed of metal cations and nonmetal anions (ex. sodium chloride)
molecular compounds
composed of atoms of 2 nonmetal anions (ex. carbon monoxide)
when a group of the periodic table becomes ions
ionic charge is positive and numerically equal to the group when positive/when negative subtract the group number from 8 to get the number** see pages 143-145
Avagadro's number
6.23*10^23
number of representative particles
1 mole (quantity)
6.022*10^23 atoms
6.022*10^23 molecules
6.022*10^23 ions
diatomic elements
(NIH)
N₂O₂F₂Cl₂Br₂I₂H₂
volume of 1 mole of liquid at STP
22.4 L
chemical reaction symbols
+ add reactants
--> yield; products come after this symbol
<--> reversable
(s) (l) (g) (aq) states
arrow with triangle on top heat was used
arrow with "Pt" on top catalyst used
types of chemical reactions
combination
decomposition
combustion
single displacement
double displacement (acid-base or precipitate)
chemical equations must be balanced so that they:_______ (reason)
obey the the law of conservation of mass
catalyst
something that speeds up a chemical reaction, but isn't used up
the calculation of quantities in chemical equations
stoichiomentry
what is conserved in a chemical reation
atoms and mass
relationship between mass of reactants and products
they are equal
percent yield (equation)
(actual yield (given) ÷ theoretical yield (found in lab))*100%
limiting reagent
determines the amount of product that can be formed in a reaction
excess reagent
reactant not completely used in a reaction