Study Guide Flashcards
Given a balanced chemical equation and the mass in grams of one reactant (where the other
reactant is in excess), calculate the amount in grams of a specified product that will be produced.
B g A g
Mol b— Mol a
#particles B #particles A
Given a balanced chemical equation, calculate the number of molecules of a specified reactant
that are required to produce a given amount (in grams) of a specified product.
B g A g
Mol b— Mol a
#particles B #particles A
Given a balanced chemical equation and the mass in grams of two reactants, determine the
limiting reactant, the maximum amount in grams of a specified product that will be produced,
and the percent yield (given the theoretical yield of a specified product).
-Limiting reactant is the reactant that makes the least product (gets completely consumed)
-theoretical yield is the least product made (the maximum amount of a product based on the limiting reactant)
- actual yield is the amount of product actually formed
% yield = (actual yield/ theoretical yield) X 100
Actual yield = (% yield X theoretical yield)/100
Theoretical yield = (actual yield X 100)/% yield
Understand and explain the key characteristics of the Bohr model of the atom.
-Electrons reside in orbits (at specific fixed distances from the nucleus )
-the energy of each orbit is indicated with a quantum number “n” (the higher the greater the energy of the orbit)
-the energy of every orbit is quantized (only have specific energy nothing in between)
Electrons must have the exact amount of required energy to go to a higher energy orbit
Write electron configurations and draw orbital diagrams for elements (you will not be tested
on any such electron configurations or orbital diagrams past element 54).
-Shell n=1 has subshell “s” which has 1 orbital that fits 2 electrons
-shell n=2 has subshell “s” “p” which has 4 orbitals that fit 8 electrons
-shell n=3 has subshell “s” “p” “d” which has 9 orbitals that fill 18 electrons
-shell n=4 has subshell “s” “p” “d” “f” which has 16 orbitals that fill 32 electrons (same for shell n=5-n7)
Subshell S has 1 orbital(box), subshell P has 3 orbitals (box), subshell D has 5 orbitals (box), subshell F has 7 orbitals (box) draw arrow up and down in the box to represent the electron, fill each box with at least one electron b/c more stable
Order 1s
2s 2p
3s 3p 3d
4s 4p 4d 4f
5s 5p 5d 5f
6s 6p 6d 6f
7s 7p 7d 7f
Diagonal lines to creat order
Given two elements, indicate their relative atomic size, ionization energy and metallic character.
-Atomic size: as you move to the left of the periodic table atomic size decreases, as you move down the periodic table atomic size increases
-Ionization energy: as you move to the left of the periodic table ionization energy increases, as you move down the periodic table ionization energy decreases
-Metallic character: as you move tot he left of the periodic table metallic character decreases, as you move down metallic character increases
Know definitions for principal quantum number (and what a small versus a large principal
quantum number means), stoichiometry (and what stoichiometry allows you to do), and limiting
reactant.
-Principal quantum number indicates the size of an orbital and its energy, the higher the number the higher the energy
-Stoichiometry is the numerical relationship between substances in chemical reactions
-Limiting reactant is the reactant that is completely consumed in a chemical reaction (which makes the least amount of product)
Know the maximum number of electrons in each of the s, p, d, and f subshells (and in a single
orbital), and what the subshell letters specify.
-Subshell S has a maximum of 2 electrons
-Subshell P has a maximum of 6 electrons
-Subshell D has a maximum of 10 electrons
-Subshell F has a maximum of 14 electrons
(Subshell letters specifies the number of orbitals, Subshell S has one orbital, Subshell P has 3 orbitals, subshell D has 5 orbitals, Subshell F has 7 orbitals)
-letter specifies the shape of an orbital and indicates the subshell.
Draw Lewis structures for covalent compounds, indicate the total number of valence electrons
of the compound, and indicate the molecular geometry of the compound.
- Add the total valance electrons
a. If you have a cation, remove an electron for each positive charge
b.if you have an anion, add an electron for each negative charge - Determine which atom is the central atom and connect the other at atoms to it with a singe line (bone *2 electrons), central atom should be the lease electro negative, but hydrogen is never a central at atom its always a terminal atom
- Complete the octets of the outer atoms first, then the central atom, any remaining electrons should be placed on the central atom
- If there are no enough electrons to give the central atom an octet, then form from multiple bonds
a.if a poly atomic ion is involved place the structure in brackets and include the charge on the upper of the bracket
Indicate the number of core electrons and valance electrons in an element.
-Valance electrons are all electrons in the outer most shell (n:1,2,3,4,5,6,7)
-Core electrons are all electrons in inner energy levels (n:1,2,3,4,5,6,7)
Using the Periodic Table, name an element based on a given period and the number of
electrons in a specific subshell.
-Groups 1-2 are S block subshells
-Groups 3-12 are D block subshells
-Groups 13-18 are P block subshells, *Except Helium which is an S block subshell
-Groups lanthanides and actinides are F block subshells
Periods determine the principal quantum number 1-7, *Except which groups 3-13 it is its period-1=principal quantum number for subshell D
Groups determine the number of the electrons on the last two subshells of a electron configuration
Given two elements, and their respective electronegativity values, determine whether a bond
formed between them is pure covalent, polar covalent or ionic.
Subtract the two elements electronegativity values compare that number with this information
0.0-0.4 = non polar (pure) covalent bond
0.5-2.0 = polar covenant bond
Greater than 2.0 = ionic bonds
Given two elements, and their respective electronegativity values, determine whether a
molecule composed of said elements is polar or non-polar.
- Draw Lewis structure
1.Determine whether the bonds are polar by determining electronegativity distance of the bonded DEN (delta electronegativity)
a.Subtract the two elements electronegativity values compare that number with this information
0.0-0.4 = non polar (pure) covalent bond
0.5-2.0 = polar covenant bond
Greater than 2.0 = ionic bonds
- It bonds are polar, than determine the molecular geometry to determine if the dipoles cancel
a. If dipoles cancel -> non-polar/pure molecule
b. If dipoles don’t cancel -> polar molecule
Molecular geometry
- Draw the Lewis structure
- Determine the number of bonding groups and lone pairs
- Determine molecular geometry by correlating the number of bonding groups and lone pairs to one of the four shapes
a. 2 bonding groups: linear
b. 3 bonding groups: trigonal planar
i) 2 bonding groups and one lone pair: bent
c. 4 bonding groups: tetrahedral
i) 3 bonding groups and 1 long pair: trigonal pyramidal
ii) 2 bonding groups and 2 lone pairs: bent
Calculate remaining mass of the excess reactant
Excess reactant - reactant that made the most product
Remaining mass = initial mass(mass given) - mass consumed
To find mass consumed
Start with limiting reactant convert to grams the moles and moles of the other reactant to grams which will be the mass consumed
Electron geometry
- Draw the Lewis structure
- Determine the number of electron groups (single,double,triple bonds, lone pairs)
- Determine electron geometry by correlating the number of electron groups to one of the indicated shapes
a. 2 electron groups: linear
b. 3 electron groups: trigonal planar
c. 4 electron groups tetrahedral
