Chemistry 12

Students learn rules for electron configuration

Students analyze trends in the Periodic Table.

Students use electronegativity to determine if the bond is ionic, polar covalent or non-polar covalent.

Students predict the shape and polarity of a molecule using VSEPR Theory.

An experiment is performed to compare the solubilities of I$_2$ (s) in different solvents, water and hexane (C$_6$H$_{14}$).

Hybrid orbitals are "mix" of atomic orbitals ($s, p, d$) that result in quivalent hybrid orbitals ($sp, sp^3, sp^3d^2$).

Types and properties of solids.

Students review the key terms and ideas found in this unit.

Substitution Reactions - hydrogen is replaced by another atom or a group of atoms.

Addition Reactions - two atoms of groups of atoms add to a double bond.

Elimination Reactions - two atoms of groups of atoms are removed forming alkene.

Oxidizing agents, [O], such as potassium dichromate (K$_2$Cr$_2$O$_4$) in sulfuric acid (H$_2$SO$_4$) and potassium permanganate (KMnO$_4$) are used to make aldehydes, ketones and carboxylic acids.

Reducing agents, [R], such as lithium aluminum hydride (LiAlH$_4$) and sodium borohydride (NaBH$_4$) are reduce aldehydes, ketones and carboxylic acids to alcohols.

Esters are produced when carboxylic acids are heated with alcohols. Sulfuric acid is used in this reaction as both a catalyst and a dehydrating agent. Water is formed along with an ester. This reaction is reversible and the hydrolysis reaction, where the ester is split into the corresponding carboxylic acid and alcohol, is also taking place.

In the first part, students investigate the use of the oxidizing agents to distinguish between primary, secondary and tertiary alcohols. In the second part, esters are synthesized by condensation of a carboxylic acid and an alcohol. This reaction is catalyzed by the sulfuric acid, which also works as a dehydrating agent by removing water from the product.

Polymers are long chains of small molecules called monomers. Polymers are often found in nature as cotton, celulose and even our DNA. They also form the basis for synthetic fibers, rubbers, and plastics. Due to their versatile uses, there is a huge interest in polymers and they are large contributors of the reasearch done today.

Polymers are typically produced using two types of reactions: addition polymerization and condensation polymerization reactions.

Thermochemistry is the study of heat released or absorbed during chemical reactions and physical changes.

Calorimetry is the technique used to measure how much heat is released or absorbed during chemical reactions and physical changes. Calorimetry is also used to measure amounts of heat transferred from a warmer object to the colder object.

A thermochemical equation is used to represent the changes in both matter and energy. In a thermochemical equation, the enthalpy change, $\Delta$H, is shown as a value included in the equation or after the equation.

Hess's Law states that if a reaction is composed of several steps, the enthalpy change of the total reaction equals the sum of the enthalpy changes of the various steps.

$\Delta$H represents the change in potential energy stored in the bonds of the products as compared with the bonds of the reactants. It is the difference between the energy required to break the bonds in the reactants and the energy released when the bonds in the products are formed.

A heating curve is a graph of the temperature of a system as a function of the heat flow into the system.

In this experiment students build their own simple coffee calorimeter to measure the temperature change during the process of dissolution. Students use the collected data to calculate the change of enthalpy of dissolution, $\Delta H_{soln}$, in $\dfrac{kJ}{mol_{solute}}$.

The 2nd Law of Theromdynamics states that increasing the entropy (disorder) of the Universe is a spontaneous process. A process is said to be spontaneous if it occurs naturally without being forced to happen. \[ \Delta S > 0 \]

Students review the key terms and ideas found in this unit.

Kinetics tell us how fast this reaction proceeds and factors that affect the speed of the reaction.

Reaction rate describes the change in a reactant or a product over time.

Integrated rate law describes the change in concentration of reactant per change in time. For the reaction: \[a A \rightarrow b B \] the rate law is:

The collision theory states that in order for reactions to take place molecules must collide.

In this experiment students measure the time it takes to form a blue-black complex.

The overall progress of a chemical reaction can be represented by a series of simple elementary steps or elementary reactions.

Students review the key terms and ideas found in this unit.

Chemical Equilibrium is the state where the concentrations of all reactants and products remain constant with time.

Students investigate what happens to the original equilibrium constant when the reaction is reversed, the coefficients are changed or the equations are addded.

Le Châtelier’s Principle states that if you disturb an equilibrium, the reaction will shift to undo the disturbance.

When the system reaches solubility equilibrium, the rate of the dissolving process equals the rate of the crystallization process.

In this experiment students use a microplate to investigate the shifts that can be observed by applying a stress onto small amounts of solutions at equlibrium.

Students review the key terms and ideas found in this unit.

Acids are proton donors and bases are proton acceptors.

Weak acids can be represented as equilibrium systems because they do not completely ionize. An equilibrium is established between a weak acid and its conjugate base.

Salts of strong acids and weak bases (NH$_3$, N$_2$H$_4$, CH$_3$NH$_2$) form acidic solutions.

Buffers are aqueous solutions that resist a change in pH when small amounts of acid or base are added.

A titration curve is produced by plotting the pH change that occurs during a titration.

In this lab a weak acid, vinegar, is titrated with a strong base, 1.2 M NaOH. This is an example of an acid-base neutralization reaction in which an acid and a base react to produce water and a salt.

Students review the key terms and ideas found in this unit.

Oxidation-reduction reactions involve a transfer of electrons from one species to another.

The half-reaction and the oxidation numbers methods are used to balance the redox reactions.

The Spontaneity Rule is derived to help determine if the reaction will or will not happen spontaneously.

A galvanic cell is capable of generating electrical energy from a spontaneous chemical reaction, for example a battery is a simple galvanic (voltaic) cell.

Electrolysis is the process of supplying electrical energy to a molten ionic compound or a solution containing ions to produce a chemical change in otherwise nonspontaneous reaction.

In this experiment students use a 9 Volt battery to perform electrolysis, or chemical decomposition, of various aqueous solutions. Students are required to make observations to help them determine the half-reactions occuring at the anode and cathode.

Students review the key terms and ideas found in this unit.

Culminating activity.