Addition Polymers

This has also been posted HERE, as part of Alkenes.

Primary Amines

Carboxylic Acids

Organic Chemistry Reaction Scheme

This image shows the key relationships between the functional groups we learn about in this topic. Can you fill in the arrows with suitable reagents? Do you know the importance of the green terms? Why is NH₂ underlined in amines? Why is the H underlined in carboxylic acids?

Alcohols - Typical Reactions

In this topic, we will do some experiments with primary, secondary and tertiary alcohols. Here are some videos explaining some of the expected observations and how to use them to identify/classify alcohols.

Alcohols - Preparation from Alkenes

There are a few ways to make alcohols:

• fermentation of sugars
• synthesis gas
• hydration of alkenes

We looked at the hydration of 1-butene using dilute sulfuric acid:

Alcohols - Structure

The structure of alcohols tells us a lot about their physical properties and chemical reactions. Last year, the first lesson was about the different isomers of C₄H₉OH, with the students starting by trying to make (and name) all of the ones that contain the alcohol functional group. Can you name these?

EXTENSION (not covered in Level 2, but worth seeing if you notice something interesting about the 3D structures of 2-butanol):

Haloalkanes

Haloalkanes are a very useful intermediate compound, often used when converting one useful compound into another. Their own uses are limited, primarily due to the impact they have on the environment. Haloalkanes are generally immiscible (insoluble in water) as they are (technically) non-polar.

Haloalkanes are the products of:

• reacting a halogen (such as bromine) with hydrocarbons.
• reacting an alcohol with Lucas Reagent (chloroalkanes produced); remember that tertiary alcohols react very quickly, while primary alcohols may not react at all.
• reacting an alcohol with PCl₃, PCl₅ or SOCl₂

Haloalkanes can be converted into:

• alkenes, using NaOH (or KOH) dissolved in alcohol (elimination reaction)
• alcohols, using aqueous NaOH (or KOH) (substitution reaction)
• amines, using excess NH₃ (substitution reaction); if you use do not use enough NH₃, it will make an amino salt instead, such as ethyl ammonium chloride

For more information about haloalkanes, click HERE (ChemGuide)

Identifying Hydrocarbons

Today, we we challenged to work out what class of hydrocarbons were in bottles labelled only as "A", "W" and "Z". Once we had it correct, we were told which hydrocarbons were in each bottle. Here is one way to present our findings if it was an NCEA question:

Alkenes (2)

Here is an introduction to two of the most simple reactions of alkenes: combustion and addition:

Next: oxidation and polymerisation.

Alkenes (1)

Alkenes are unsaturated hydrocarbons. The functional group is a C=C bond (double bond). This lesson is based around the isomers and nomenclature of alkenes:

Here is an activity that shows alkenes have the same general formula as cyclic alkanes:

Here another activity which is just a little tougher:

Introduction to Organic Chemistry - Alkanes

I'm not a fan of teaching this topic the way Beginning Chemistry does. The following blog posts will be how I taught this in 2014. Hopefully this will complement the work being done in class with our student teacher.

I prefer to "get into it" with the functional groups and cover types of reactions, nomenclature and isomerism over and over again, in context. So, we jumped straight into using MolyMods to make as many isomers of C₅H₁₂ as possible.

Here are the questions we tried at the start of the next lesson:

Revision Lesson: Equilibrium

Revision Lesson: Energy Changes

Revision Lesson: Molecule Polarity

Revision Lesson: Solid Types

Today we did a brief overview of the one of the topics that will be in an Achievement Standard in our upcoming exam:

pH Overview

Today, I taught Mrs Naseem's class and we did an overview of pH and pH Calculations. Here are the whiteboard notes that I gave them. They may be useful to complement the work we did in class:

pH of Strong Bases

One of the more difficult skills is calculating the pH of a strong base. To do this, we need to know how to find the hydronium ion concentration from the hydroxide ion concentration:

Acids and Bases Videos

Here are some videos of the key concepts being taught in previous years:

2013

2014



2013


2013


2014

Acids, Bases, Conjugates and Amphiprotic Species

There is a very useful definition of acids and bases worth remembering:

Acids = "proton donors"
Bases = "proton acceptors"

Then, we looked at the pH of some salts and tried to justify the results. For example:

To clarify, ammonium chloride was acidic and sodium ethanoate was alkaline.