Final Flashcards
What is a molecule
at least two atoms held together by chemical bonds (may contain atoms of the same element or different elements)
What is an ion
an atom or group of atoms with a net positive or negative charge
what is a cation
an atom with a net positive charge
what is an anion
an atom with a net negative charge
What is a molecular formula
a formula which shows the exact number of atoms of each element
what is an allotrope
one of two or more distinct forms of an element (carbon diamond and graphite)
what is the empiracal formula
a formula which tells us which elements are present in simplest whole number ratio (simplist chemical formula
what do organic compounds usually have
contain carbon in combo with elements like hydrogen, nitrogen, oxygen, and sulfur.
what is a cation derived from
metal atoms (with exception of NH4)
How do you name an ionic compound (compound composed of a metal cation and a nonmetal anion)
you say the name of the metal then add ide to the second compound
For ionic compounds, how do you determine the charge on the second atom
based on which group they’re in. (N nitride or N3- is in group 3)
What is a molecular compound usually composed of
Two nonmetal elements.
How do you name a molecular compound
Same way as a an ionic compound however you also add prefixes to the last atom (SO2 sulfur dioxide)
What is an acid
a substance which yeilds hydrogen ions (H+) when dissolved in water
True or false, acids always contain one or more hydrogen atom
true
hydrogen chloride (HCl) breaks up into what when dissolved in water
hydrochloric acid (H+ and Cl-)
what is avagadros number used for
to determine the number of atoms in something
what is the unit for molecular mass
amu
how do you determine amu
by adding up all the atomic masses
what is the equation for percent composition by mass of a compound
(the number of moles in element)(atomic mass of element)/(molar mass of compound) then mulitply the entire thing by 100%
How do you determine the empiracal formula of a compound when given the percent compositions
assume the percentage is equivalent to grams. Convert grams to moles. Then divide each solution by the smallest number of moles. Then use those answers as subscripts for each element
How do you go about solving a stoichiometry problem
- write the balanced equation
- make sure reactant are in moles
- use mole ratio to find number of moles formed
- convert moles back to grams or whaterver unit desired
What is a limiting reactant
the reactant which is used up first
what is the theoretical yield of a reaction
the amount of product which would result if the limiting reagent reacted
How do you calculate percent yeild
(actual yeild)/(theoretical yeild) x 100%
What is an electrolyte
a substance that when disolved in water can conduct electricity
what is a strong electrolyte
a compound which dissociates 100% into ions
Is HCL a strong weak of non-electrolyte
strong
what is ionization
the separation of acids and bases into ions
what is hydration
the process in whcih an ion is surrounded by water molecules
What is a precipitation reaction
A reaction which results in the formation of an insolubale product known as precipitate
What makes an acid
when a substance ionizes in water to produce H+ ions
What defined a base
the production of OH- molecules when the substance is disolved in water
What are a few common characteristics of acids
- sour taste
- cause color change
- react with metals
4 conduct electricity - react with carbonates and bicarbonates
what are some common characteristics of bases
- bitter taste
- slippery
- cause color change
4 conduct electricity
According to Bronsted, what determines if something is a base or acid
an acid is a proton donor and a base is a proton acceptor
what are oxidation reduction and redox reactions considered
electron transfer reactions
What is an oxidation reaction
a half reaction which involves the loss of electrons
hat is a reduction reactions
a half reaction which involves the gaining of electrons
what is the oxidation number/state
the number of charges the atom would have in a molecule if electrons were transferred completely
What are some rules for determining oxidation numbers
- free elements (O2, K, F, H2) all have oxidation 0
- monoatomic ions oxidation # = charge on the ion
- oxygen is -2 except for (h2O2 & O22-)
- hyrogen is +1
- Flourine is -1.
- neutral molecule sum of oxidation #s should = 0
- oxidations don’t have to be integers
what is a combination reaction
when two or more substances combine to form a single product
what is a decomposition reaction
the breakdown of a compound into two or more componenets
what is a combustian reaction
when a substance reacts with oxygen
what is a displacement reaction
when an ion or atom is replaced be an ion or atom of a different element
How do you determine the molarity (M) or molar concentration of a solution
(moles of solute )/(liters of solute) OR n/v
How do you calculate the dilution of a solution
MiVi = MfVf
True or false, ionic compounds exist as gases at 25 degrees celsius and 1 atm
False
What are some properties of gases
- assume the volume/shape of container
- most compressible state of mater
- gases will mix evenly in same container
- gases have very low density
what is 1 Newton equivalent to in kg
1 kgm/s2
how do you calculate pressure
force/area
what is boyles law
that the pressure of a fixed amount of gas at a constant temp is inversley proportional to the volume of the gas
what is the relationship between pressure and volume
P1V1=P2V2
what is the realtionship between volume and temperature
V1/T1=V2/T2
what is r = to in the ideal gas law equation pV=nRT
the gas constant (0.0821 Latm/Kmol)
how do you calculate energy
force*distnace
How many Joules is 1 Kilojoule worth
1000J in 1 kJ
What is relationship between pressure, temper, and volume when n is constant
P1V1/T1=P2V2/T2
what is the definition of heat in chemistry terms
the transfer of thermal energy between two bodies that are different temperatures
what is an exothermic process
any process that gives off heat
what is an endothermic process
when heat is supplied to the system
How do you determine the energy change on a system
energy change is (U) = heat exchange (q) and work done on or by the system (w)
what is the equation for work in thermodynamics
work = -pressure (p) * change in volume (V)
What is the conversion for Joules to Liters or atm
1L*atm = 101.3J
How do you calculate change in enthalpy
delta H= change in U + P*change in V
How do you calculate the enthalpy of a reaction
delta H = H(products)-H(reactants)
How do you calculate heat capacity (C)
Heat capacity (C) = mass (m) * specific heat (S)
what are some equations for calculating the amount of heat (q)
q=msAt
q=CAt
How do you calculate the speed of a wave (u)
u= wavelength (lamda) * frequency (V)
what other way can you think of an atomic orbital
the wave function of an electron in an atom
What is the principal quantum number (n)
the energy of the orbital. Has integral orbitals like 1, 2, 3, 4, 5.
What is the angular momentum orbital (l) and how does it relate to the principal quantum number
It is the shape of the orbital and it depends on what n is.
What is the magnetic quantum number
describes the orientation of the oribtal in space
what does it mean if an orbital is dimagnetic or paramagnetic
if it’s dimagnetic all electrons are paired and if its paramagnetic not all electrons are paired/eenrgy level is not full
How do electron configurations correlate with group number of elemtents
they are the same. All elemetns in gruop 1 will have 1 valence electron and etc.
what is the pattern of atomic radii in the periodic table
as you move down and to the left atomic radii increases
Which has a larger atomic radius a cation or anion
anions
what is ionization energy
the minimum energy required to remove an electron from a gaseous atom in its ground state
how does ionization energy increase across the perioidc table
as you go up and across. same as electronegativity
what gruop is more reactive, alkalai metals or alkalai earth metals
alkalai metals (1A)
which group on the periodic table is the most stable
8A
Are halogens found in elemental form in nature
no, they are way too reactive
What is an ionic bond
the elctrostatic force that holds ions together in an ionic compound
If an element has a low electron afinity, is it morel ikley to form cations or anions
cations
if an element has a high electron afinity is it more likley to form an anion or cation
anion
what group is most likley to form cations
alkali metals and alkaline earth metals
what happens to the electrons in an ionic bond
they are trasnferred
what is lattice energy
the stability of any ionic solid
what is a covalent bond
A bond where two electrons are shared
what is a lone pair
a pair of valence electrons that are not involved in covalent bond function
what determines if you have a polar or non-polar covalent bond
The electronegativity
what are the steps to writing a lewis structure
- write the skeletal structure with the most electronegative atom in the center
- count up all the valence electrons
- draw a single bond between the central atom and each surrounding one and complete the octets of each surrounding atom.
- After, if the central atom doesn’t have an octet still, add double and tripple bonds.
What is the most likley form of a lewis structure
the one with the smallest/no formal charges
what is the formal charge of an atom and how do you calculate it
the formal charge is the electrical difference between the valence electron an an isolated atom and the number of electrons assigned to the atom in a lewis structure.
You find it by subtracting the number of electrons drawn on the atom from the number of valence electrons the atom actually has
give an example of a molecule which can form an incomplete octet
BeH2 and BF3
give an example of a molecule which can have an expanded octet
SF6
How do you determine dipole moments
based on eelctronegativity and the shape of the molecule
what is hybridization
the mixing of atomic orbitals in an atom (usually the central one)
How do you determine the hybridization of an orbital
it is equal to the number of pure atomic orbitals (Add up orbitals)
How do you determine the hybridization of an orbital
it is equal to the number of pure atomic orbitals (Add up orbitals
how many orbitals does sp3d hybrid orbitals contain
5
how many pi and sigma bonds are there in a singular convalen bond
1 sigma bond
how many pi and sigma orbitals are there in a double covalent bond
1 sigma, 1 pi
How many pi and sigma bonds are there in a triple covalent bond
1 sigma, 2 pi
what is the speed of light
3 x 10*8
