Chem Flashcards
Synthesis
Making building
2 or more atoms compounds combine to form a new substance
Balancing equations
Remember only an arrow not an =
just make sure there are equal amounts on each side
atoms can leave compounds
Deomposition
Break down into two or more atoms
Single displacemnt
AKA sustitution reactions
a single element replaces another
A + BC - AC +B
Double displacement
Atoms in different compounds switch places to form two new compounds
AB + CD - AD +CB
Combustion
Burning of a hydrocarbon (compound containing only carbon and hydrogen atoms), in the prescence of oxygen
Hydrogen + oxygen - carbon dioxide + water
Incomplete combustion results in
Any combination of carbon containing compounds
Neutralization
Becomes water and ionic, acid and base cancel out each other. Special kind of double displacement, the hydrogen from the acid reacts with the hydroxide from the base to form H2O
Binary acids
Hydrogen and single non-metal
Oxyacid
Hydrogen and a polyatomic (oxy means oxygen)B
Bases
A molecule with a base of hydroxide or carbonate, or ammonia
Ph scale
How acidic or alkaline (basic)
goes from 0 to 14
Number alkali vs acid
0-6 acid
7 water
8-14 more alkaline
what does ph stand for
Power of hydrogen, concentrartion of Hydrogen
What is a base
pulls protons
What is an acid
Pulls electrons
Atomic Theory
All matter is made of atoms. Atoms of a pure substance are identical. Atoms can’t be created or destroyed. Atoms combine in simple ratios to form compounds
Who created atomic theory
democritus (400 BCE)
John Dalton 1807
JJ Thomson discovery in 1897
electrons
Marie Curie 1903
radiation
Ernest rutherford 1909, 1917
Atomic nucleus, protons
Niels Bohr 1913
electrons occupy discrete energy levels
James Chadwick 1932
neutrons
proton
in nucleus, 1amu, + charge, atomic number
neutron
in nucleus, 1 amu, no charge, mass number-atomic number
electron
outside nucleus, 1/1887 amu, - charge, atomic number
Isotope is a
variation of an elemont with a different number of neutrons.
Isotopses are refered to by their
mass number
you can specity the isotope you are refrencing by using isotope notation. What is isotope notation
A (Mass number)
X (element symbol)
Z (Atomic Number)
Bohr rutherford is useful for predicting
the behaviour of atoms
Bohr rutherford neutrons and protons are in the, electrons
center of the diagram (nucleus) electrons are drawn in specific energy levels (shells, rings, orbitals)
Energy levels
2, 8, 8, 2, for the first energy level draw both electrons together
Gilbert lewis
covalent bond, dot structures, coined term “photon”
Lewis diagram shows
the chemical symbol and only the outermost valence energy level of electrons
Atoms are more stable when
they have a full valence shell
elements with fewer than 4 valence
metals, will lose electrons to create and full and stable shell
elements with more than 4 valence will
non-metals, gain electrons to create a full shell
an atom has a positive charge if
it has lost an electron and has more protons than electrons
an atom has a negative charge if
it has gained electrons, so it has more electrons than protons, thus it has a negative charge
positive ion is called, negative ion is called
cation, anion
elements in the same family (column)
devolp the same ionic charges
metals tend to
lose electrons thus forming cations
non-metals tend to
gain electrons, thus forming anions
ions are
atoms that have lost or gained one or more elctrons resulting in a positive or negative charge.
ionic compound is formed when
electrons are transfered creating positive or negative charges
binary ionic compoud is
composed of a metal and a non-metal (cation and anion). The term binary indicates that ther are only 2 components
naming binary ionic compounds
state the name of the metal, the the non metal changing the ending to ide
writing chemical formulas for binary ionic compounds
write symbols begining with metal, write ionic charge (no + or -), cross over the number writing in subscript (no subscript of 1), reduce to lowest terms
Some metals are able to form more than one ion we call these metals
multivalent meaning “multiple valence”, for example copper can form ions with a charge of +1 or +2, Cu+1 is pronounced copper one
when you are refering to a multivalent metal you must
indicate which ion you are using in the name of the compound
Ions formed from the attraction of several atoms are
covalent polyatomic, polyatomic means multipe atoms
though polyatomic compounds are made of many atoms they
function as one specific ion
a binary compound is composed of , a ternary compound is composed of
two, three
polyatomic ions end with ? exceptions
ate, hydroxide, ammonium, cyanide
naming polyatomic compounds
state the name of the cation (when multivalent indicate in roman numerals), state name of the anion
writing formulas for polyatomic compounds
write symbols begininning with cation, write charges over each symbol, cros charges over, if polyatomic has charge greater than 1 put in brackets, reduce
Some elements are not strong enough to pull electrons away from other elements the elements
tend to share electrons in order to complete their outer shell
molecular compounds are formed
when atoms of two or more different elements share electrons
a covalent bond is formed
when electrons are shared between atoms
binary molecular compounds are
compounds composed of two non-metals joined by one or more covalent bonds,
naming covalent bonds
change the first non-metal to have the charge as if multivalent,
prefixes 1,2,3,4,5
mono, di, tri, tetra, penta
though we use the stock system you will see prefix system. give examples
carbon dioxide, carbon monoxide, carbon tetracloride, dinitrogen pentoxide
what is a molecular formula
a chemical formula. It shows the number of atoms of each element.
what is a structural formula
shows arrangement of atoms that make up a molecule
diatomic elements
in their natural state do not exist as individual atoms. Rather they exist naturally in pairs of atoms joined by one or more covalent bonds froming a molecule
which elements are diatomic
Hydrogen, Oxygen, Bromine, Florine, Iodine, Nitrogen, Chlorine
As discrete elements not in compounds we wrute diatomic elements as
H2, O2, Br2, F2, I2, N2, CL2
Diatomic elements are gases
at room temperature except for. Bromine which is a liquid and iodine which is solid
Lewis Diagram - ionic
Draw lewis for each element, draw arrow electron transfer, both ions must have full electron shells, finish by drawing brackets around the chemeical symbols with their valence shells and charges above
Covalent Lewis Diagram
draw the lewis diagram for each, share electrons, simplify with lines
in chemical reactions no
new mass is created, but rather atoms are rearranged to produce new combinations and thus new substancec
word equationa and chemical equations
chemists use equations to describe chemical reactions. Word equations show the names of each compounds and chemical equations show the formulas of the materials in the chemical.
Reactants -> producst
Starting substance turns to ending substance
Solid
state symbol s
liquid
l
gaseous
g
aqueous
dissolved in water aq
Antoine Lavoisier
discovery of oxygen in combustion, metric system, revised chemical nomenclature, law of convservation mass. “the father of modern chemistry”
law of conservation mass
in a chemical reaction the total mass of the products will be the total mass of the reactants
We need to balance the chemical equation by adding
coefficients in front of each chemical. we can’t change the formulas only the amount of each compound
Ph paper
Acid-orange
neutral-yellow
base-blue
blue litmus paper
acid-orange
neutral-same
base-blue
red litmus paper
acid-same
neutral-same
base-blue
HBB (bromothymol blue)
acid-yellow, neutral-green, base-dark blue
Hpp (PHenolpthalein
acid-pale blue, neutral-mirky blue, base-dark purple
Element
a pure substance that cannot be broken down further into a simpler substance. Made up of only one type of particle
compound
a pure substance that can be broken down further into simpler substances. Made up of two or more elements
period
a horizontal row of eleemtns (left to right) on the periodic table
family, group
a vertical column of eleemtns up/down on the periodic table
