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Table of Contents
Matter and Chemical Bonding_______________________________3Structure of matter______________________________________________________3
Atom________________________________________________________________3Element______________________________________________________________3Compound____________________________________________________________3Group (columns)_______________________________________________________3Period (rows)__________________________________________________________3Drawing structures______________________________________________________3Molecule_____________________________________________________________3BOFINCH____________________________________________________________3
Periodic Law____________________________________________________________4Atomic size___________________________________________________________4Ionization energy_______________________________________________________4Electron Affinity_______________________________________________________4Electronegativity_______________________________________________________4Electropositivity________________________________________________________4
Octet rule______________________________________________________________4Cations_______________________________________________________________4Anions_______________________________________________________________4Isotopes______________________________________________________________4
Bonds__________________________________________________________________5Ionic bonding__________________________________________________________5Covalent bonding_______________________________________________________5Polarity of molecules____________________________________________________5
Reactions_______________________________________________________________5Metals and alloys_______________________________________________________5Metal reactivity series___________________________________________________6
Quantities in Chemical Reactions_________________________7Basic Concepts__________________________________________________________7
Mole_________________________________________________________________7Avogadro’s Number____________________________________________________7Molar mass____________________________________________________________7Law of definite proportions_______________________________________________7Stoichiometry__________________________________________________________7Percentage yield________________________________________________________7Empirical and Molecular formulas_________________________________________7Molar volume__________________________________________________________7Limiting reactant_______________________________________________________7General Problem_______________________________________________________8Empirical Formula Problem______________________________________________8Molecular Formula Problem______________________________________________8
1
Limiting and Excess Reactant Problem______________________________________9
Formulas_______________________________________________________________9
Solution and Solubility_______________________________________10General terms__________________________________________________________10
Water as a solvent_____________________________________________________10Concentration of a solution______________________________________________10Solute_______________________________________________________________10Polar Solvent_________________________________________________________10Solution_____________________________________________________________10
Acids and Bases________________________________________________________10
Formulas______________________________________________________________11
Gases and Atmospheric Chemistry______________________12Standard conditions_____________________________________________________12
Laws and Formulas_____________________________________________________12Boyle’s Law__________________________________________________________12Charles’ Law_________________________________________________________12Gay-Lussac’s Law_____________________________________________________12Combined gas Law____________________________________________________12Dalton’s law of partial pressure___________________________________________12Ideal Gas Law________________________________________________________13
Hydrocarbons and Energy__________________________________14Types of alkanes______________________________________________________14Types of alkenes______________________________________________________14Type of alkynes_______________________________________________________15Naming hydrocarbons__________________________________________________15Naming branches______________________________________________________15Isomers______________________________________________________________16Cyclos______________________________________________________________16Combustion__________________________________________________________16Endothermic and Exothermic reactions_____________________________________16
Types of Calorimeters___________________________________________________17Calorimeter__________________________________________________________17Bomb calorimeter_____________________________________________________17Enthalpy_____________________________________________________________17Calorimeter Problem___________________________________________________17
2
Matter and Chemical BondingStructure of matter
AtomSmallest particle of an element
ElementComposed of only one type of atom
CompoundMixture of two or more elements (NaCl)
Group (columns)Elements in a group share similar chemical and physical properties
Period (rows)Elements in a period have the same number of energy shell
Drawing structures
Bohr Diagram Lewis Diagram Lewis Diagram
MoleculeCombination of two more atoms of the same element
BOFINCH
3
A (mass number, the number of protons and neutrons [mass number - electrons])
E (the element)
Z (atomic number, the number of protons)
H2S
Periodic Law
Atomic size As we go down a group, the size of the atom’s increase As we go across a period (left to right), the size of the atom decreases
Ionization energy Ionization energy is the minimum amount of energy required to completely
remove an electron from a gaseous atom Ionization energy deceases down a group Ionization energy increases as we go across a period (left to right)
Electron Affinity Electron affinity is how much the element wants an electron Electron Affinity deceases down a group Electron Affinity increases as we go across a period (left to right)
Electronegativity The tendency for an atom to attract electrons to itself Electronegativity decreases down a group Electronegativity increases across a period (left to right)
Electropositivity The tendency for an atom to lose an electron Electropositivity increases down a group Electropositivity decreases across a period (left to right)
Octet rule
Cations Metals for cations (positive ion) Cations are smaller than the atom they represent
Anions Non-metals for anions (negative ion) Anions are bigger than the atom the represent
Isotopes Isotopes are made up of the same atomic number but different mass
number (number of neutrons)
The saying B O F I N C HThe molecules Br2 O2 F2 I2 N2 Cl2 H2
State Liquid Gas Gas Solid Gas Gas Gas
4
Bonds
Ionic bondingIonic bonding occurs when a metal transfers one or more electrons to a non-metal (in an effort to obtain a stable valence shell)
Properties Usually solid and have high melting and boiling points Usually conducts heat and electricity when in solution
Covalent bondingCovalent bonding occurs when two or more non-metal share electrons (in an effort to obtain a stable valence shell)
Properties Usually do not conduct electricity or heat as a solid Usually do not dissolve in water
Polarity of molecules If the Electronegativity is low, it is a non-metal If the Electronegativity is high, it is a metal
Reactions Synthesis: A + B → C (like cooking, many ingredients but only one result) Decomposition: C → A + B Single displacement: A + BC → B + AC (the cations moves) Double displacement: AB + CD → CB + AD (the cations moves) Complete combustion: A + O2→ CO2 + H2O Incomplete combustion: A + O2 → CO2 + H2O + CO + C Neutralisation acid + base → salt + water (acids have H; bases have OH) No Reaction: A + B → No Reaction (in certain cases, the cations may not
be able to move; to find out when, observe the metal reactivity series)
Metals and alloysMetals Solids are malleable and
ductile Conductors of heat + electricity
High melting and boiling point As you go down a group, the
elements become more metallic
5
3.3 1.7 0.9 0
IONIC POLAR COVALENT COVALENT
1.7 = ionic
0.9 = covalent
AlloysCombinations of 2 or more metals (examples: steal or brass)Rarely found in nature because metals normally require some sort of man-made chemical reaction
Metal reactivity seriesElement Displacement in reactionsLi Able to move H2 from H2OK Able to move H2 from H2OBa Able to move H2 from H2OCa Able to move H2 from H2ONa Able to move H2 from H2OMg Able to move H2 from acidsAl Able to move H2 from acidsZn Able to move H2 from acidsCr Able to move H2 from acidsFe Able to move H2 from acidsCd Able to move H2 from acidsCo Able to move H2 from acidsNi Able to move H2 from acidsSn Able to move H2 from acidsPb Able to move H2 from acidsH Able to move H2 from acidsCu Able to move H2 from acidsHg Able to move H2 from acidsAg Able to move H2 from acidsPt Able to move H2 from acids
Least reactive
Most reactive
Quantities in Chemical ReactionsBasic Concepts
Mole The number of atoms in exactly 12 grams of carbon-12Number of moles = n
Avogadro’s NumberThe number of atoms (or molecules) in one mole of a substance6.02 × 1023
Molar massThe mass of one mole of a substance (element or compound)Molar Mass = MrMr = add the mass of every element in the compoundDo not count the coefficient
Unit =
Law of definite proportionsA compound always contains exactly the same proportion of elements by mass
StoichiometryThe study of quantitative (measurable) relationships of the reactants and products in balanced chemical reactions.
Percentage yieldMeasure the effectiveness of the experiment.
Empirical and Molecular formulasEmpirical formula: Simplest form of atoms
Molar volumeThe volume occupied by 1 mole of any gas @ STP is 22.4L (called molar volume)
Limiting reactantA reactant completely consumed in a chemical reaction
Excess reactant
Empirical formula Molecular formulaH2O H2OHO H2O2
The reactants that are left behind in a chemical reaction
Problems
General Problem1 mole of CO2 is equal to
a) 6.02 × 1023 moleculesb) 2 moles of Oc) 1 moles of Cd) 44.0095 grams e) 22.4 L @ STPf) 31.9988 grams of Og) 12.0107 grams of C
Empirical Formula ProblemA compound consists of 72.2% Mg (Magnesium), 27.8% N (Nitrogen). What is the empirical formula? The Molar Masses:
1. n (Mg) = 24.3050 2. n (N) =14.0067
Elements % Mass (g) Divide by small Multiply till whole
Mg 72.2 72.2 2.97
N 27.8 27.8 1.98
Answer: Mg3N2
Molecular Formula Problem
If the molar mass of the compound is 100.9 , what is the molecular formula?
Empirical formula = Mg3N2
Empirical mass
Molecular formula = (Empirical Formula) X
X
Limiting and Excess Reactant ProblemSilver nitrate and sodium phosphate have reacted in equal amounts of 200 grams each. What is the limiting reactant?
Steps Sodium nitrate Sodium phosphateChemical 3AgNo3 Na3Po4
Mass (g) 200g 200g
Molar Mass169.87 163.94
Ratio moles1.18 mol 1.22 moles
Divide by coefficients0.392 1.22
Answer: Limiting reactant is Sodium nitrate
Formulas
[N = number of atoms, ions or formula units]
Answer: Mg3N2
X
Solution and SolubilityGeneral terms
The smaller the particle size, the faster the reaction The higher the temperature, the faster the reaction
Water as a solventWater is able to dissolve other substances. There is hardly a substance known which has not been identified in solution in water.
Concentration of a solution How much solute and solvent there is. A solution can be concentrated or dilute.
SoluteThe substance to be dissolved
Polar SolventThe substance doing the dissolving the dissolving
SolutionA homogenous mixture composed of two or more substances
Acids and BasesAcids Bases
Ph [potential hydrogen] is under 7 Ph [potential hydrogen] is over 7H+ ion OH- ionAcid + Phenolphthalein = colourless Base + Phenolphthalein = pinkHCl; H2So4; H3Po4 NaOH; LiOH
SupersaturatedBarely anything dissolved
Saturated A couple are not dissolved
Unsaturated Completely dissolved
Formulas
Gases and Atmospheric Chemistry
Standard conditions0°C = 273 K1 atm = 101.352 kPa = 101,325 Pa = 760 Hg = 760 torr1L = 1000 ml = 1000 cm3 = 1dm3
Temperature is always in Kelvin and is represented by a capital “T”
Laws and Formulas
Boyle’s Law Pressure and volume are inversely proportionate when temperature is at a
constant If pressure increases, volume decreases [temperature is constant]
Charles’ Law Volume and temperature are proportionate when pressure is at a constant If volume increases, temperature increases [pressure is constant]
Gay-Lussac’s Law Pressure and temperature are proportionate when volume is at a constant If pressure increases, temperature increases [volume is constant]
Combined gas Law The ratio between the pressure-volume product and the temperature of a
system remains constant
Dalton’s law of partial pressure The sum of the individual pressures of all the gases that make up a mixture
is equal to the total pressure
The partial pressure of each gas is equal to the mole fraction of each gas multiplied by the total pressure
Ideal Gas Law
P= pressure in atmosphereV=volume [litres]n=Number of moles of gasR=Universal Gas Constant 0.0821 Litres x atmosphere / moles x KelvinT=Temperature [Kelvin]
Hydrocarbons and Energy
Hydrocarbons are compounds that contain only hydrogen and carbon. There are three types: alkanes, alkenes and alkynes.
1) Alkanes: their general formula is CnH2n+2 → single bond2) Alkenes: their general formula is CnH2n → double bond3) Alkynes: their general formula is CnH2n-2 → triple bond
Types of alkanesNumber of Carbon atoms Name
1 Methane2 Ethane3 Propane4 Butane5 Pentane6 Hexane7 Heptane8 Octane9 Nonane
Alkanes have single bonds only. Diagrams of alkanes are:
Methane (CH4) Ethane (C2H6)
CH3 CH3
Structural Condensed
Types of alkenes Number of Carbon atoms Name
1 Methene2 Ethene3 Propene4 Butene5 Pentene6 Hexene7 Heptene8 Octene9 Nonene
Alkenes have double bonds as well as single bonds. When naming alkenes, it is important to number the carbon atoms, giving the double bond the lowest number:
prop-1-ene: pent-2-ene:
__
Type of alkynes
Number of Carbon atoms Name1 Methyne2 Ethyne3 Propyne4 Butyne5 Pentyne6 Hexyne7 Heptyne8 Octyne9 Nonyne
Alkynes have triple bonds as well as single bonds. When naming alkynes, as with alkenes, it is important to number carbon atoms, giving the triple bond the lowest number:
pent-3-yne: but-1-yne:
Naming hydrocarbons1) Find the largest continuous chain.2) Identify the branches of the longest chain.3) Name the branches.4) If there are 2 or more branches, the carbon closest to the branch gets the lowest
number.5) Branches of the same type use prefixes. Commas are used between numbers and
hyphens between numbers and letters. 6) If there is more than one type of branch, name the branches in alphabetical order.7) If there is more than one chain that could be the main chain, select the chain with
the most branches attached.
Naming branchesNumber of Carbon atoms Name
1 Methy2 Ethyl3 Propyl4 Butyl5 Pentyl6 Hexyl7 Heptyl8 Octyl9 Nonyl
The prefixes for when there are more than one branch of the same type are:Number of branches Prefix
1 -2 Di3 Tri4 Tetra5 Penta6 Hexa7 Hepta8 Octa9 Nona
Isomers Isomers organic compounds with the same molecular formula but different structural formulas Butane 2-methyl Propane
CyclosCycloalkanes are hydrocarbons that form geometric shapes when drawn out into their structural diagrams. There are also cycloalkenes and cycloakynes. The same rules apply.
Cyclobutane: Cyclopentene: Cyclopropene:
CombustionComplete combustion of alkanes equations are: CnHn+ O2= CO2+ H2O. Incomplete combustion of alkanes equations are: CnHn+ O2= CO2+ H2O + CO+ C
Endothermic and Exothermic reactionsEndothermic reactions absorb heat (energy) [cold]. Examples are dissolving a chemical in water (a medical cold pack) and any reaction where a bond is broken. Exothermic reactions release heat (energy) [hot]. Examples are combustion equations and any reaction where a bond is made.
They have the same number of carbons and hydrogen’s (molecular formula), but they have different configurations (structural formulas)
Types of Calorimeters
CalorimeterA calorimeter measures energy change
Q=m c Δt
Q is the heat content (thermal energy) m is the massc is the specific heat capacity Δt is the temperature change
Bomb calorimeterBomb calorimeters measure energy change much more accurately that the calorimeter. They are also much more expensive.
Q= C Δt
Q is the heat content (thermal energy) C is the heat capacity Δt is the temperature change
Enthalpy
Problems
Calorimeter Problem
100g of water (c = 4.184 ) are placed in a calorimeter. The heat of
the water is measured to be 15.6 °C. 0.568 g of calcium is added to the water, and a chemical reaction takes place. The final temperature of the solution is 26.3°C. How much heat is released per mole of calcium?
For this question, you will use the following formulas:
Q is measured in Joules (J) or Kilojoules (KJ).m is measured in grams (g).
c is measured in
Δt is measured in °C.
Q is measured in Joules (J) or Kilojoules (KJ).
C is measured in
Δt is measured in °C.
“n” can change depending on the question
In this case it is n because the question asks how much heat is released per mole of calcium
Step 1
Step 2
Step 3
Step 4
Answer:
-315903 Joules are released per mole