Titration Curves

Buffers

What is a buffer? What skills do I need to answer questions about buffers?

How do I calculate the pH of a buffer solution?

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pH Calculations

Ionic Product and the Common Ion Effect

Solubility Product and Solubility - Calculations

Solubility

Most substances are actually soluble in water; what we previously described as being insoluble may actually only be sparingly soluble. Therefore, some of the substance may be dissolving. We use a solubility product and solubility (in grams per litre, or in moles per litre) to describe the how well a solute will dissolve.

Ions in Solution

With this, we have to identify which ions are in the solutions we were given, then rank them from highest to lowest concentration.

Electrochemical Cells

Electrochemical cells involve two half-cells: one where oxidation occurs and one where reduction occurs. When connected and placed in a circuit, these chemical reactions generate an electric potential (voltage) and a current.

Electrolysis

Electrolysis is a process by which electrical energy is used to convert compounds into their elements.

More amazing science.

Scientists are on a roll this year. 

First they created the perfectly optimised bit, then were able to observe an electron cloud and now this.

Scientists directly measure Van der Waals force.

Reactions of Potassium Permanganate

The reduction of KMnO₄ is different under acidic, alkaline and neutral conditions:

Here is a wonderful summary of the reactions of KMnO₄:

Solubility

Enthalpy

What is Enthalpy? 

The following video does go further than you need, but gives a good explanation:

Enthalpy: Understanding why enthalpy can be viewed as "heat content" in a constant pressure system.

Enthalpy of Formation

Heat of Formation: Standard heat of formation or standard enthalpy change of formation.

Enthalpy of Formation values can be very useful for calculating the enthalpy change in a reaction. There are two ways to do this:

METHOD ONE

• Find the sum of the enthalpies of formation of the products.
• Find the sum of the enthalpies of formation of the reactants.
• Subtract the latter from the former.

METHOD TWO

• Write out the equations that each enthalpy of formation represents
• Use Hess' Law

Hess's Law and Reaction Enthalpy Change: Using Hess's Law and standard heats of formation to determine the enthalpy change for reactions

Enthalpy of Fusion and Enthalpy of Vaporisation

Intermolecular Forces

Last year, we learned about ionic bonds, covalent bonds, van der Waals forces and metallic bonds. We still need to know about these this year, but now need to understand hydrogen bonds and need to know more about van der Waals forces.

Lewis Structures

Here are the videos of this concept being taught to a Year 12 class:

So that is what we are expected to remember from last year. This year, things get a little more difficult; we need to know how to draw Lewis Structures which do not obey the Octet Rule and for polyatomic ions:

BEHOLD!!!

A must see use of scientific resources for fun.

World's Smallest Stop-motion movie

Ionisation Energy

We need to know a fair bit about Ionisation Energy:

1. Define 1st I.E.
2. Justify the trend in 1st I.E. down a Group
3. Justify the trend in 1st I.E. across a Period
4. Use consecutive I.E. values to infer electron configuration/number of valence electrons.

Periodic Table Trends: Ionization Energy: What an ion is. Using the periodic table to understand how difficult it is to ionize an atom.

Electronegativity

Electronegativity generally increases across a Period and generally decreases down a Group. We need to be able to justify these trends this year: