The General Chemistry Series
Determination of Water hardness
CHemistry 231 + Lab
This is regarding the general chemistry sequence for students typically majoring in the sciences such as biology, chemistry, pharmacy, and chemical engineering. Chemists study the composition and transformations of matter and there are various specialties one can pursue. In the beginning of the term typically professors cover units of measurement, the reliability of measurement, significant figures and conversions. Here’s an idea on how to prepare for chemistry before hand.
In lab, students learn to develop plans for weekly experiments and are expected to learn proper laboratory etiquette including data collection and proper use of Excel. In my opinion, the planning was the most challenging portion of the labs. Students are also expected to write a paper scientific paper on 1 laboratory experiment. Here is a link to my PDF for conversions: steps-made-easy between moles, atoms, and molar mass.
It will be important to be able to distinguish between atoms and molecules and explain the differences between physical and chemical changes. Also covered this term, was the quantum mechanical model of the atom, periodic properties of the elements, polyatomic ions, chemical bonding and chemical reactions. Here is a list of polyatomic ions commonly used, a VSEPR sheet, and a pictorial representation of atomic orbitals for reference. Some memorization was needed but, overall to meet the learning objectives understanding and being able to explain major concepts was key to succeeding in this class.
Key Concepts
Energy is the capacity to do work and is often reported in units of Joules
Chemistry is done in moles
In chemical and physical changes matter often exchanges energy with its surroundings
Atomic Theory
Electron configuration
Materials Referenced
Chemistry Book
Dr. Tyler DeWitt videos (holds a Ph.D. in Microbiology from MIT)
Khan Academy
Professor Dave Explains
Molecular Orbital Theory Explained
Lab notebook
Supplementary resources
Doodles in the Membrane
Helpful Infographics Visualize Complex Branches of Math and Science
Top Ten Chemistry Experiments from Pivot Interactives
1. Ideal Gas Law: PV = nRT (pressure times volume equals number of moles times gas constant times temperature)
2. Boyle's Law: PV = k (pressure times volume is a constant for a fixed amount of gas at constant temperature)
3. Charles's Law: V/T = k (volume divided by temperature is a constant for a fixed amount of gas at constant pressure)
4. Avogadro's Law: V/n = k (volume divided by number of moles is a constant for a fixed amount of gas at constant temperature and pressure)
5. Henderson-Hasselbalch Equation: pH = pKa + log([A-]/[HA]) (relates the pH of a weak acid solution to the pKa of the acid and the ratio of the concentrations of its conjugate base and acid forms)
6. Nernst Equation: Ecell = E°cell - (RT/nF)ln(Q) (relates the cell potential to the standard cell potential, temperature, Faraday constant, and reaction quotient)
7. Gibbs Free Energy: ΔG = ΔH - TΔS (relates the change in enthalpy, entropy, and temperature to the change in free energy)
8. Beer-Lambert Law: A = εbc (relates the absorbance of a solution to its molar extinction coefficient, path length, and concentration)
9. Rate Law: Rate = k[A]^x[B]^y (relates the rate of a chemical reaction to the concentrations of reactants)
10. Equilibrium Constant: Kc = [C]^c[D]^d/[A]^a[B]^b (relates the concentrations of reactants and products at equilibrium)
Chemistry 232 + lab
The entire series builds off CH231 and students explore the principles of chemistry including gases, liquids, solids, solutions, kinetics, equilibrium, acids and bases. The course heavily involves prior algebra skills. Although this was a heavy course load, I took the entire 200 level chemistry series with the 200 level physics series and found many concepts overlapped.
Again, every professor structures the class differently. Ultimately the biggest contributor to my success was the end of book chapter questions, repetitive practice, and studying the homework assigned to us in class. I didn’t use out side resources as the text required was very thorough.
Lab was set up identically to the first semester. In terms of workload this term was about the same. It required a minimum if 15 hours a week of studying for me to feel comfortable with the concepts. Students are expected to create plans for each weekly experiment, know how to reference a chemical SDS sheet, and provide explicit data collection and procedure. Again another written lab report and presentation was required. Tips on writing a chemistry paper found here.
Key concepts
Gas Laws: My favorite helpful video
Intermolecular forces
Entropy of Solutions
What makes a good buffer system?Equilibrium constant
Electron affinity refers to the energy associated with an element in its gaseous state gaining an electron (no general trend)
The Lewis Model
Ionic, covalent, hydrogen and metallic bonding
Solubility
Develop titration skills in lab
Understand the properties of molecules are directly related to their shapes
Electronegativity is the ability of an atom to attract electrons to itself in chemical bonding.
Reaction stoichiometry
Writing balanced equations I used this worksheet for practice
Key Equations
Formula mass
Mass percent composition
Empirical Formula Molar Mass
Mass-to-mass conversions: Stoichiometry
Stoichiometry step by step
Percent Yield made easy
Solution Dilution
Relationship between work, pressure and changes in volume
Heat of a Bomb Calorimeter: more info also found here
Relationships between enthalpy, internal energy, pressure and volume
M1V1 = M2V2
Additional sources and continuing education
Molecular Foundations and Global Frontiers
Master in Chemistry, Pearson
Here are some basic chemistry rules that may be helpful:
1. Law of conservation of mass: Matter cannot be created or destroyed in a chemical reaction. The total mass of the reactants equals the total mass of the products.
2. Law of definite proportions: A compound always contains the same elements in the same proportion by mass, regardless of its source.
3. Law of multiple proportions: When two elements combine to form different compounds, the mass ratios of the two elements in the compounds are always in small whole-number ratios.
4. Octet rule: Atoms tend to gain, lose, or share electrons in order to achieve a stable electron configuration with eight valence electrons.
5. Periodic law: The properties of elements are periodic functions of their atomic number.
6. Aufbau principle: Electrons fill orbitals in order of increasing energy, starting with the lowest energy level.
7. Pauli exclusion principle: No two electrons in an atom can have the same set of four quantum numbers.
8. Hund's rule: Electrons in the same subshell occupy different orbitals with the same spin before pairing up.
9. Acid-base reactions: Acids donate protons (H+) and bases accept protons. The products of an acid-base reaction are a salt and water.
10. Oxidation-reduction reactions: Oxidation is the loss of electrons, and reduction is the gain of electrons. The products of a redox reaction are an oxidized substance and a reduced substance.
Chemistry. 233 + Lab
This term continued to build off CH231 and CH232. Due to the Covid-19 pandemic this class was taken entirely remote, so my study habits changed. This term we focused on aqueous solutions and precipitation reactions, pH and buffer systems, titration curves, balancing redox reactions, and predicting spontaneous direction. The class explores the experimental and theoretical principles of chemistry including solubility equilibria, acid-base equilibria, electrochemistry, nuclear chemistry, metals and organic compounds.
Tip:
If you are continuing on to organic chemistry, recollection of acid base reactions is important. However, in a 300 level cellular and molecular biology and biochemistry course fundamental knowledge in the entire general chemistry series and relevant equations is required.
Key concepts
Understand the definition of the Arrhenius definition of acids and bases as well as the Bronstead-Lowry definition
Arrhenius Equation, k=Ae-Ea/RT
Polyprotic acids
Know how to find OH and pH of strong and weak base solutions
Properties of transition metals
These characteristics of an electrochemical cell:
1. Electrodes: An electrochemical cell consists of two electrodes, namely the anode and cathode. The anode is the electrode where oxidation occurs, while the cathode is the electrode where reduction takes place.
2. Electrolyte: The electrolyte is a conductive medium that allows the flow of ions between the electrodes. It can be a liquid, gel, or solid containing ions that participate in the electrochemical reactions.
3. Redox Reactions: Electrochemical cells involve redox (reduction-oxidation) reactions. Oxidation occurs at the anode, where electrons are lost, while reduction occurs at the cathode, where electrons are gained. These reactions involve the transfer of electrons and ions.
4. Electron Flow: The electrochemical cell facilitates the flow of electrons from the anode to the cathode through an external circuit. This electron flow creates an electrical current that can be harnessed for various applications.
5. Cell Potential: The electrochemical cell has a cell potential, also known as electromotive force (EMF) or voltage. It represents the driving force for the electron flow and is measured in volts (V).
6. Salt Bridge: In some electrochemical cells, a salt bridge is used to maintain electrical neutrality and balance the charges between the two half-cells. It allows the movement of ions to prevent a buildup of charge that could impede the cell's operation.
7. Types of Cells: Electrochemical cells can be divided into two main categories: galvanic (voltaic) cells and electrolytic cells. Galvanic cells produce electrical energy from spontaneous redox reactions, while electrolytic cells require an external power source to drive non-spontaneous redox reactions.
8. Applications: Electrochemical cells have various applications, including batteries, fuel cells, electroplating, corrosion prevention, and sensing devices.
Oxidation vs reduction
Electrode potentials
Nuclear Chemistry
Key Formulas
Expression for the Acid Ionization Constant : explore more on Khan Academy here
Expression for the pOH scale
The Henderson-Hasselbalch Equation
Know the effective buffer range:
pH = pKa ± 1.
Define Ampere: The ampere (A), the SI base unit of electric current. One coulomb is equal to about 6.241 x 1018 electric charges (e). One ampere is the current in which one coulomb of charge travels across a given point in 1 second.
Standard Hydrogen Electrode
Equation for cell potential
Eocell = Eoreduction + Eooxidation
Ecell = cell potential at non-standard state conditions
Eocell = standard state cell potential
R = constant (8.31 J/mole K)
T = absolute temperature (Kelvin scale)
F = Faraday's constant (96,485 C/mole e-)
n = number of moles of electrons transferred in the balanced equation for the reaction occurring in the cell
Q = reaction quotient for the reaction.
aA + bB cC + dD
The Nerst Equation
Common Chemistry equations
Additional Study Material
Acid and Base worksheets
Bronsted Acid-Base Concepts
Crash course: Electrochemistry
TDW Science: Balancing Chemical Equation practice
Chemistry Science Videos
More chemistry laws and formulas:
1. Henry's Law: The amount of gas that dissolves in a liquid is proportional to the partial pressure of the gas above the liquid.
2. Raoult's Law: The vapor pressure of a solution is proportional to the mole fraction of the solvent in the solution.
3. Charles's Law of gases: At constant pressure, the volume of a gas is directly proportional to its absolute temperature.
4. Gay-Lussac's Law of gases: At constant volume, the pressure of a gas is directly proportional to its absolute temperature.
5. Dalton's Law of partial pressures: The total pressure of a gas mixture is the sum of the partial pressures of the gases in the mixture.
6. Hess's Law: The enthalpy change of a chemical reaction is independent of the pathway between the reactants and the products.
7. Coulomb's Law: The force between two charged particles is proportional to the product of their charges and inversely proportional to the square of the distance between them.
8. Faraday's Law of electrolysis: The amount of a substance produced at an electrode during electrolysis is proportional to the amount of electric charge that passes through the electrode.
9. Law of mass action: The rate of a chemical reaction is proportional to the product of the concentrations of the reactants raised to their stoichiometric coefficients.
10. Arrhenius Equation: The rate constant of a chemical reaction is proportional to the exponential of the activation energy divided by the product of the gas constant and the absolute temperature.
Chemists have diverse skill sets and knowledge that can be applied to various industries and sectors.
Here are some common job options for chemists:
1. Research Chemist: Conducting research, experiments, and analysis to develop new products, technologies, or processes.
2. Analytical Chemist: Performing chemical analysis and testing on substances and samples to determine their composition, quality, and characteristics.
3. Pharmaceutical Chemist: Working in the pharmaceutical industry to develop and test drugs, analyze drug formulations, and ensure compliance with regulatory standards.
4. Quality Control Chemist: Monitoring and testing products or materials to ensure they meet quality standards and specifications.
5. Environmental Chemist: Studying the impact of chemicals on the environment, analyzing pollutants, and developing strategies for environmental protection and remediation.
6. Forensic Chemist: Applying chemical analysis techniques to analyze evidence in criminal investigations, such as analyzing drugs, toxins, or trace evidence.
7. Materials Scientist: Studying the properties, composition, and structure of materials to develop new materials or improve existing ones for various applications.
8. Food Chemist: Working in the food industry to develop and analyze food products, ensuring safety, quality, and compliance with regulations.
9. Polymer Chemist: Studying and developing polymers, including plastics and rubber, for various applications such as manufacturing, coatings, and adhesives.
10. Petrochemical Chemist: Working in the petroleum and oil industry, involved in the research, production, and analysis of chemicals derived from petroleum.
11. Academic or Industrial Researcher: Conducting research in academic institutions or private industries, exploring new areas of chemistry and publishing scientific papers.
12. Chemical Sales Representative: Promoting and selling chemicals, laboratory equipment, or scientific instruments to businesses and research institutions.
These are just a few examples, and the field of chemistry offers a wide range of opportunities across various industries, including pharmaceuticals, energy, manufacturing, agriculture, and more.
