Naming Esters the IUPAC Way

IUPAC naming of esters is not a bit hard, it's just a bit different to the way you name other organic molecules.

Follow AUS-e-TUTE's step-by-step guide to :

• naming esters
• drawing the structure of ester molecules
• writing the molecular formula for ester molecules

and you'll be amazed at how easily you can name, and draw the structure of, esters.

Then, when you think you've got the hang of that, why not try our ester naming game?
Or, test your skill with our ester test.
Preparing for an exam? We've got you covered! You can use our ester exam to practice your exam technique before you sit your exam.
And remember, AUS-e-TUTE's test and exam questions come with immediate feedback to help you understand where you go wrong and help you get the next question right.

AUS-e-TUTE Members should log-in to use these new resources. 

Not an AUS-e-TUTE Member?
There is currently a "free-to-view" tutorial available at http://www.ausetute.com.au/namester.html

Find out more about AUS-e-TUTE membership at : http://www.ausetute.com.au/membership.html
and you can join AUS-e-TUTE at http://www.ausetute.com.au/register.html

2015 Chemistry Calendar

Yes, the 2015 Chemistry Calendar is here!
Yes, it's free to download (it's a pdf)!
And yes, it has been redesigned, but you'll have to download one to see why the 2015 Chemistry Calendar is the best calendar we've made so far ........

Go to http://www.ausetute.com.au and click on any of the links to the download page.

Naming Alcohols the IUPAC Way

Alcohols are organic molecules that have the OH (hydroxyl or hydroxy) functional group.
Learn how to apply the IUPAC rules for naming different types of alcohols:

• Naming Straight-Chain Alkanols
• Naming Branched-Chain Alkanols
• Naming Straight-Chain Alkanediols

and learn how to classify alcohols as primary, secondary or tertiary at

• Classification of Alcohols

AUS-e-TUTE Members also have access to additional teaching and learning sources.

Find out about AUS-e-TUTE membership here

and when you're ready to start improving your ability to answer Chemistry questions correctly, you can join AUS-e-TUTE here

Writing Chemical Formula

The chemical formula for the ammonium ion is NH₄⁺.
In order to write this formula correctly you MUST show:

• capital (or uppercase) N for the element nitrogen
• capital (or uppercase) H for the element hydrogen
• a subscript number 4 to indicate the presence of 4 hydrogen atoms in the molecule
• a superscript + sign to indicate that the molecule has a positive charge

When you answer a question at ausetute.com.au requiring a chemical formula, you will need to use the buttons on the textbox provided to make a subscript number and a superscript charge sign.

Here is a quick lesson in how to type your chemical formula into the textbox so that it displays the correct formula and not an incorrect formula (like NH4+)

Amides

You spell amine with an "n" and amide with a "d", but what other differences are there?

AUS-e-TUTE has just added new resources for naming primary amides (primary alkanamides).
AUS-e-TUTE Members should log-in to use the new tutorial, game and test.

If you are not an AUS-e-TUTE Members then there is a "free-to-view" tutorial currently available for evaluation purposes at http://www.ausetute.com.au/nampamide.html

You can find out about how AUS-e-TUTE can help you improve your chemistry results at http://www.ausetute.com.au/membership.html

and when you're ready to start improving your chemistry results you can join AUS-e-TUTE at http://www.ausetute.com.au/register.html

Naming Amines

Need help to name amines?

AUS-e-TUTE has just added new resources for naming primary alkanamines (simple amines) using the preferred IUPAC system of nomenclature.
Members should log-in to use the new tutorial, game, test and exam.

Non-members can access a "free-to-view" tutorial at http://www.ausetute.com.au/nampamine.html

AUS-e-TUTE Members have access to thousands of test and exam questions with worked solutions to help you learn how to answer chemistry questions.
Why not find out more information about the benefits of an AUS-e-TUTE Membership at http://www.ausetute.com.au/membership.html

and when you're ready to start improving your chemistry results, join AUS-e-TUTE at http://www.ausetute.com.au/register.html

Aldehydes and Ketones

Help with naming aldehydes and ketones is now available.
AUS-e-TUTE has just uploaded new resources (games, tests, tutorials) to introduce students to the preferred IUPAC system for naming alkanals (simple aldehydes) and alkanones (simple ketones).

AUS-e-TUTE members should log-in to use these new resources: http://www.ausetute.com.au

"Free-to-view" tutorials are currently available for non-members:
Naming Alkanals: http://www.ausetute.com.au/namalkanal.html
Naming Alkanones: http://www.ausetute.com.au/namalkanone.html

Information about membership is available at: http://www.ausetute.com.au/membership.html
and you can join AUS-e-TUTE at http://www.ausetute.com.au/register.html

Aspartame

In September 2014, NutraSweet Company, producer of the artificial sweetener NutraSweet containing aspartame, announced plans to close its aspartame manufacturing business and focus on more profitable lines of sugar substitutes.

Controversy has surrounded the use of aspartame in food since its introduction in the 1980s.

It has been alleged that aspartame is responsible for causing headaches, Alzheimer's disease, multiple sclerosis, even cancers.

So, what is aspartame and why is it used?

Go to the December 2014 issue of AUS-e-NEWS to find out!

Not a subscriber? Go to http://ausetute.com.au/contact.html to subscribe to our newsletter.

Carboxylic Acid Nomenclature

Learning to name alkanoic acids (simple carboxylic acids) has never been easier thanks to AUS-e-TUTE's latest resources.
AUS-e-TUTE Members should log-in to the Members Only area to access the new tutorial, game and test questions with worked solutions.

Not an AUS-e-TUTE member?
A free tutorial is currently available for evaluation purposes at
http://ausetute.com.au/namalkacid.html

For membership information  go to http://ausetute.com.au/membership.html

To join AUS-e-TUTE go to http://ausetute.com.au/register.html

Sulfuric Acid and Sugar

November 28, 2014, The Canberra Times reported that, "Students were looking on as a teacher conducted an experiment involving sugar and sulfuric acid inside a cabinet when the glass container holding the acid exploded."
The experiment referred to is probably similar to the one shown in the YouTube video below in which concentrated sulfuric acid from a container is poured over sugar in a beaker.

Safety Notes

Sulfuric acid will cause permanent damage if it comes into contact with the eyes or skin. Concentrated solutions of sulfuric acid are extremely corrosive. When sulfuric acid is dissolved in water enough heat is released to make water boil! Carbon monoxide and carbon dioxide are both toxic gases. Sulfur dioxide gas is toxic in high concentration and is a severe respiratory irritant at lower concentration.Some people, especially those prone to asthma, may be especially sensitive to sulfur dioxide. In the presence of moisture, sulfur dioxide forms an acidic, corrosive solution, which in contact with the skin or eyes may lead to burns.

You will notice that the reaction seems to proceed slowly at first. The reaction mixture turns yellow as the reaction begins. This reaction releases heat, it is said to be an exothermic reaction. The heat produced by the reaction then speeds up the rate of further reactions, and, in the video, this is also accelerated by stirring the mixture.

Table sugar is made up sucrose, molecular formula C₁₂H₂₂O₁₁ and structural formula as shown below:

The reaction between sucrose and sulfuric acid in which solid carbon, water vapour and heat are produced is known as a dehydration reaction  :
C₁₂H₂₂O₁₁(s) → 12C(s) + 11H₂O(g)     ΔH = -918.9 kJ mol^-1 Since the enthalpy change for this reaction is negative, the reaction is exothermic, the reaction gives off heat.
Sulfuric acid molecules have a great affinity for water, that is, sulfuric acid will readily and spontaneously dissolve in water. The water produced by the dehydration of sucrose will then be used to dilute the sulfuric acid that is present. This reaction is also exothermic.
H₂SO₄(l) → H₂SO₄(aq)     ΔH = - kJ mol^-1 The heat produced by this reaction also speeds up the rate of the dehydration reaction and subsequent dilution reactions.
Solid carbon is black, so the "black snake" is just carbon.
But what causes the carbon to "rise up" out of the beaker? This must be the result of evolving gases forcing their way through the mixture as the reaction proceeds. The gases that have been identified as products of this reaction  are:

• carbon monoxide (CO) 66% of the dry gas volume (ie, water has been condensed out)
• carbon dioxide (CO₂) 17% of the dry gas volume
• sulfur dioxide (SO₂) 17% of the dry gas volume

Since sulfuric acid does not oxidize carbon, it is most unlikely that the carbon monoxide and carbon dioxide gases are the result of a reaction between the black snake carbon and sulfuric acid. It is much more reasonable to assume that some of the sucrose undergoes dehydration by the sulfuric acid while some this sucrose (and/or some of the resulting intermediate organic products) is oxidized by the sulfuric acid to produce carbon monoxide gas and carbon dioxide gas. During this process, the sulfuric acid will itself be reduced, resulting in the formation of sulfur dioxide gas.

Reference:
http://www.canberratimes.com.au/act-news/students-treated-after-spill-in-burgmann-anglican-school-sciencbe-laboratory-20141128-11vzad.html

Further Reading:
http://ausetute.com.au/safety.html
http://www.ausetute.com.au/mmcalcul.html  
http://www.ausetute.com.au/moledefs.html
http://www.ausetute.com.au/massmole.html
http://www.ausetute.com.au/concsols.html 
http://www.ausetute.com.au/molarvol.html
http://www.ausetute.com.au/molreact.html

Suggested Study Questions:

1.  Describe two hazards in the YouTube Video.
2.  Describe the safety precautions you would take to minimize the risk of the hazards identified in question 1 above.  
3.  Why do you think the concentrated sulfuric acid is added to the sugar rather than adding the sugar to the container of sulfuric acid?
4.  In a typical experiment, 25 mL of 18 mol L^-1 sulfuric acid is added to 50 g of granulated sugar (sucrose). Calculate the amount in moles of :
   • sucrose used
   • sulfuric acid used
5. Calculate the mass of carbon that could be produced in the typical experiment given in question 4.
6. What assumptions have you made in order to calculate the mass of carbon in question 5?
7. Assume that all 50 g of the sucrose is now oxidized at 25^oC to produce carbon dioxide gas and liquid water. What is the maximum volume of carbon dioxide gas, in litres, that could be produced?
8.  Predict what you think might happen if a 50 g of granulated sugar were quickly added to 25 mL of concentrated sulfuric acid in a 100 mL conical flask that was being swirled continuously.
9. Sucrose is a disaccharide, made up of the monosaccharide glucose and the monosaccharide fructose. Starch and cellulose are both polysaccharides, that is, they are made of repeating glucose monomer units. Predict what would happen if you spilled concentrated sulfuric acid on:
   • a paper cup (cellulose)
   • a piece of raw potato (starch)
   • a cotton shirt (cellulose)
10. Design an experiment that could safely be performed in the laboratory to test your predictions in question 9.
11. Do you think that concentrated sulfuric acid will react with the monosaccharide glucose? Explain your answer using a chemical equation.
12.  Design an experiment that could safely be performed in the laboratory to test your prediction in question 11.

Joules, Kilojoules and Calories

What units are used to measure energy?
Well, that depends on who you are and what you are doing!
If you are a chemistry student, your preferred unit should be joules, but it is likely that you will have to convert between joules and kilojoules quite often.
You might also come across calories and kilocalories as a unit of measurement of energy, and you will then need to convert between these units, and between these and joules and kilojoules.

AUS-e-TUTE has set of resources to help you learn how do these conversions, and to practice your conversion skills.

There is currently a free-to-view tutorial available for evaluation purposes at:

http://www.ausetute.com.au/energyconv.html

The Smell of Freshness

Organic compounds are added to cleaning products and air fresheners to make the air smell fresh and clean. Scientists are taking a closer look at the chemistry behind the use of these compounds to determine whether they are hazardous to human health.

One of the organic compounds that is widely used to provide the "smell of freshness" is a molecule known as limonene (1-methyl-4-(1-methylethenyl)-cyclohexene). The 2-dimensional structural formula of limonene is shown on the right.

Limonene is a colourless liquid at room temperature and pressure and is found naturally in the rind of citrus fruits such as lemons. It is one of the compounds that contributes to the typical odour of citrus fruit.
Commercial quantities of limonene are produced from citrus fruits using centrifugal separation or steam distillation.

Scientists are studying the reactions of limonene closely because the chemical reactions of this molecule with the ozone in the air in your home are the same as the chemical reactions that occur in the atmosphere that produce secondary organic aerosols (SOAs), microscopic particles suspended in the air, which contribute to the visible haze known as smog in densely populated areas.

The researchers tested various different scenarios for the production of SOAs in the home from limonene and found that the concentration of SOAs produced was between 5μg/cm³ and 100μg/cm³. The acceptable level of aerosols in breathable air is about 12μg/cm³.

The researchers suggest that the best way to reduce SOAs in your home is to either use unscented cleaners or to keep windows open while cleaning. 

Reference:
Somayeh Youssefi, Michael S. Waring. Transient Secondary Organic Aerosol Formation from Limonene Ozonolysis in Indoor Environments: Impacts of Air Exchange Rates and Initial Concentration Ratios. Environmental Science & Technology, 2014; 48 (14): 7899 DOI: 10.1021/es5009906

Further Reading:
Empirical Formula
Molecular Formula
2-Dimensional Structural Formula
Condensed Structural Formula
Skeletal Structural Formula
Percentage Composition
Parts Per Million (ppm) Concentration
Molar Mass

Suggested Study Questions:

1. Write the molecular formula for limonene.
2. Give the empirical formula for limonene.
3. Calculate the percentage of
   • carbon in a molecule of limonene
   • hydrogen in limonene
4. Draw a skeletal structural formula for limonene.
5. Limonene has the IUPAC name 1-methyl-4-(1-methylethenyl)-cyclohexene. Draw the 2-dimensional structural formula for limonene and circle each of the following groups:
   • cyclohexene parent hydrocarbon in red
   • methylethenyl branch in blue
   • methyl branch in black
6. Would you classify limonene as a saturated or unsaturated hydrocarbon? Explain your answer.
7. Convert these concentrations in μg/cm³ to concentrations in parts per million (ppm)
• 5μg/cm³
• 12μg/cm³
• 100μg/cm³
8. Calculate the molar mass of limonene.
9. Calculate the mass of limonene in 100 L of air at 25^oC and 100 kPa for each of the following concentrations:
   • 5μg/cm³
   • 12μg/cm³
   • 100μg/cm³

IUPAC Nomenclature and Organic Compounds

Imagine you are sitting a Chemistry exam.
The first question on the exam paper reads,

"Name the molecule shown below:"

How would you answer this question?

My first response is to name it Molly, short for molecule ofcourse. Not a very useful name, especially if I'm asked to name another molecule later on. It might get a bit confusing if I name every molecule Molly, even when the molecules are very different from each other.

So, the International Union of Pure and Applied Chemistry (IUPAC) has developed systems for naming compounds.
For this reason, you probably won't be asked to "name" the molecule, but you might be asked to "systematically name" the molecule, or to give the "systematic IUPAC name" for the molecule.

Even for the relatively simple molecule shown above, there is more than one way to systematically name the molecule using IUPAC nomenclature rules!

You could give a systematic IUPAC name based on the functional class of the compound. This molecule belongs to the functional class known as ketones (non-terminal C=O), two methyl (CH₃) groups are attached to the carbonyl carbon atom, so, according to the IUPAC rules for functional class nomenclature, I could systematically name it as dimethyl ketone.

I could give the same molecule a different systematic IUPAC name by applying the rules of substitutive nomenclature. In this case I name the parent hydride, propane, drop the final "e" and add a suffix denoting the non-terminal C=O functional group so that I get propanone, then I add in an infix which locates the functional group along the carbon chain, with the final name propan-2-one.

Because this is a simple molecule with just one functional group, I could use the infix as a prefix, so that the systematic IUPAC name would become 2-propanone. Or, because there is only one position for the C=O functional group to be in if this molecule is to be a ketone, I could drop the infix altogether and just systematically name the molecule as propanone.

So, some of the possible systematic IUPAC names for this molecule are:

• dimethyl ketone
• propan-2-one
• 2-propanone
• propanone

Because molecules can be named systematically in more than one way, there is a recommendation to adopt "preferred IUPAC names", or PINs. Usually the Preferred IUPAC Name is arrived at by using one of the recognized IUPAC systems for nomenclature, but not always.

If you were asked to give the Preferred IUPAC Name for the molecule shown above, the correct answer would be acetone ("Preferred names in the nomenclature of organic compounds" (Draft 7 October 2004) page 9), or, possibly propan-2-one ("Preferred names in the nomenclature of organic compounds" (Draft 7 October 2004) page 374). Acetone is the traditional name for this compound, literally meaning 'derived from acetic acid', and has been in use for more than 200 years, which is probably why the IUPAC would consider retaining the name "acetone" as the Preferred IUPAC Name for this compound.

Further Reading:
Introduction to Naming Organic Compounds

Nanoscopy

The Nobel Prize in Chemistry for 2014 has been awarded to Eric Betzig, Stefan W. Hell and William E. Moerner for the development of super-resolved fluorescence microscopy. This technique allows scientists to view objects at the nanometre scale and is therefore referred to as nanoscopy.

Since the 17^th century, we have been able to peer into the world of very small things using optical microscopes. In 1873, microscopist Ernst Abbe published an equation to show that optical microscopes could not be used to investigate things that were less than half the wavelength of light, that is, to be seen in an optical microscope the object must be greater than 0.2µm. An optical microscope can therefore be used to see some surface structure of a human hair, but you couldn't use it to see the actual protein building blocks making up the hair.

Stefan Hell was working on fluorescence microscopy, using fluorescent molecules to image parts of a cell. A brief pulse of light makes the fluorescent molecules glow temporarily, following the glow allows scientists to map where the molecules are in the cell. The technique can be used to tell where DNA is located for instance, but it could not be used to determined its structure. Stefan Hall proposed a new method, Stimulated Emission Depletion (STED) in which one pulse of light excites all the fluorescent molecules while another pulse quenches the fluorescence from all the molecules except those in a nanometre-sized volume in the middle. Only this volume is registered. An image is built up be sweeping along the sample and continually measuring light levels. In 2000 Stefan Hall was able to demonstrate the effectiveness of the STED microscope by imaging an E.coli bacterium at a resolution that could never be achieved using an optical microscope.

The nanoscopy method proposed independently by Eric Betzig and W E. Moerner, Single-Molecule Microscopy differs in that it relies on the the superposition of several images.

In 1989, W E. Moerner measured the light absorption of a single molecule for the first time.
W E. Moerner had found that one variant of green fluorescent protein (extracted from fluorescent jellyfish) could be made to fluoresce with light of 488nm wavelength, but that after awhile, the fluorescence faded and would not fluoresce again using 488nm light. The same protein, when hit by light of wavelength 405nm could be brought back to life, and then would fluoresce again when hit with light of 488nm.

In 2006 Eric Betzig demonstrated the usefulness of Single-Molecule Microscopy using a glowing protein coupled to a cell's lysosome. Using a weak light pulse, only some of the molecules were caused to fluoresce, and these were at distances greater than 0.2µm. This image was registered. When the fluorescence of these molecules died out, a new weak light pulse was used to initiate the fluorescence of a few more molecules.This new image was registered. This process was continued many times. When Betzig superimposed all the images, a super-resolution image of the cell's lysosome membrane was the result.

Methyl Orange

In March 2014, the Australian Competition and Consumer Commission (ACCC) prompted the recall of some clothing for having unacceptable concentrations of particular azo dyes.

Azo dyes are organic (carbon) compounds with the general formula R-N=N-R' and are named after their unusual N=N, azo, functional group.

They are synthetic dyes used to colour foods, cosmetics, carpets, clothes, leather and textiles.

The azo dye that most Chemistry students will be familiar with is methyl orange, an acid-base.

Read more in the September 2014 issue of AUS-e-NEWS for the chemistry of Methyl Orange

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Email us!

Ammonium Nitrate Explodes

On Friday 6^th September 2014, a truck carrying 56 tonnes of ammonium nitrate exploded after rolling over near a bridge on the Mitchell Highway between Cunnamulla and Charleville in the Australian State of Queensland. Eight people were injured, and the Mitchell Highway has been closed "indefinitely".

The most important use for ammonium nitrate is as a fertilizer, but it can also be used as an explosive. An explosion results when ammonium nitrate is brought into contact with heat, a source of ignition such as a spark, or, with reducing agents. Unfortunately, explosions of ammonium nitrate are not rare. A massive explosion of ammonium nitrate on 17^th April 2013 resulted in the death of 15 people, and the destruction of the West Fertilizer Company storage and distribution facility in Texas, USA.

Ammonium nitrate can be produced in commercial quantities by reacting ammonia gas with  nitric acid.

Reference: 
http://www.brisbanetimes.com.au/queensland/truck-explosion-injures-eight-closes-mitchell-highway-20140906-10dam3.html

Further Reading
Naming Ionic Compounds 
Writing Ionic Formula 
Mole Definitions 
Molar Gas Volumes

Suggested Study Questions:

1. Write the chemical formula for ammonium nitrate 
2. Explain why this compound is considered to be an ionic compound.
3. Write a word equation for the reaction between ammonia gas and nitric acid to produce ammonium nitrate
4. Write a balanced chemical equation for the reaction in question 3.
5. Ammonium nitrate decomposes in to N₂O and H₂O when heated. Write a balanced chemical equation for this reaction.
6. Calculate the molar mass of ammonium nitrate.
7. Calculate the moles of ammonium nitrate present in the truck.
8. Assuming that the decomposition of ammonium nitrate results only in gaseous products, what volume of gas at 25^oC and 100 kPa would be released by ammonium nitrate in the truck?
9. Assume the truck could carry a load with a volume of 30,000 L. Can you suggest a reason why rapidly decomposing ammonium nitrate could explode, destroying the truck, the bridge and the road?

Indicators and End Points

What colour is an indicator at the end point ?
At what pH does an indicator change colour?
Why is the colour change for an indicator always given as a range of pH values?

These questions are all addressed in AUS-e-TUTE's new Indicator End Point resources.
Read the tutorial, play the game, do the test and view worked solutions for the questions.

Not an AUS-e-TUTE Member?
There is currently a free-to-view tutorial available at http://ausetute.com.au/endpoint.html

Want to find out more about how an AUS-e-TUTE Membership will help you improve your understanding of chemistry, and, improve your exam results?
Then go to http://ausetute.com.au/membership.html

Ready to join AUS-e-TUTE ?
Go to http://ausetute.com.au/register.html

Got questions?
Contact us at http://ausetute.com.au/contact.html

Sulfuric Acid - Sodium Hydroxide Titrations

Why does a titration of sulfuric acid using sodium hydroxide have only one equivalence point?
Why isn't the pH 7 at the equivalence point?

These are both excellent questions.

So, we've written a set of resources to help you understand!

AUS-e-TUTE Members should log-in and go to the new tutorial at:
http://www.ausetute.com.au/members/titrh2so4.html
and you can follow the links to the game and test from this page.

Not an AUS-e-TUTE member?
Part of this tutorial is currently available free to non-members for evaluation purposes at
http://ausetute.com.au/titrh2so4.html

Calculating the pH of Sulfuric Acid

How do you calculate the pH of a strong diprotic acid, that is, how do you calculate the pH of sulfuric acid?
I'm glad you asked!
AUS-e-TUTE has just added a new set of resources designed to help you answer this question.

AUS-e-TUTE Members should log-in and go to the links for the Polyprotic Strong Acids tutorial, game and test, on the Test Centre homepage, or, alternatively, go to your AUS-e-TUTE syllabus study guide and follow the links from that.

Not a member?
There is a "free-to-view" tutorial currently available for evaluation purposes at
http://www.ausetute.com.au/polyproticsacid.html

Titration Techniques

What piece of glassware should you use to make a standard solution?
What should you rinse a burette with before filling it with solution?
Should you force all the solution out of a pipette when you use it?

These and many other questions about Titration Techniques have been addressed in AUS-e-TUTE's new tutorials, games, tests, and exams.

Members should log in to use all these new resources which are listed under Volumetric Analaysis, or, use the links from your Syllabus Study Guide in the Members Only Test Centre.

A "free-to-view" tutorial on titration techniques is currently available for evaluation purposes for non-members: http://ausetute.com.au/titrtech.html

DOSS and Oil Spills

The molecular formula for dioctyl sodium sulfosuccinate, DOSS, is shown on the right. This is the anionic detergent molecule that was used to disperse the oil from the Deepwater Horizon spill in the Gulf of Mexico in 2010. When applied to an oil spill, DOSS decreases the size of oil droplete and prevents large oil slicks from forming.
BP applied about 1.84 million gallons of DOSS to the 210 million gallons of oil that is estimated to have gushed out of the oil well.
At the time it was believed that DOSS degraded rapidly in the environment so that it would not harm the marine environment.

Recent studies, however,  have shown that DOSS persists in the environment for much longer than was previously thought. Four years after the Gulf oil spill, DOSS remains present in deep-sea sediments and corals and in sand patties on Gulf beaches. mean for marine life or for the people who frequent the beaches? Scientists do not yet know what this might mean for marine life or for the people who frequent the beaches so some Gulf beaches have signs to warn people not to touch the sand patties.

Reference:
Helen K. White, Shelby L. Lyons, Sarah J. Harrison, David M. Findley, Yina Liu, Elizabeth B. Kujawinski. Long-Term Persistence of Dispersants following the Deepwater Horizon Oil Spill. Environmental Science & Technology Letters, 2014; 1 (7): 295 DOI: 10.1021/ez500168r

Further Reading:
http://www.ausetute.com.au/members/detergent.html (detergent tutorial for members)
http://www.ausetute.com.au/members/soaps.html (soaps tutorial for members)
http://www.ausetute.com.au/members/molecularformula.html (molecular formula tutorial for members)
http://www.ausetute.com.au/members/structural2D.html  (2-dimensional structural formula tutorial for members)
http://www.ausetute.com.au/members/condensedsf.html (Condensed structural formula tutorial for members)
http://www.ausetute.com.au/members/skeletal.html (Skeletal formula tutorial for members) 

Suggested Study Questions:

1.  Explain why dioctyl sodium sulfosuccinate, DOSS, is an anionic detergent molecule.
2. Give the name for the type of formula shown for dioctyl sodium sulfosuccinate, DOSS, in the article
3. Identify the functional groups found on a dioctyl sodium sulfosuccinate, DOSS, molecule.
4. Identify areas of the dioctyl sodium sulfosuccinate, DOSS, molecule that are:
   • hydrophilic
   • hydrophobic
5. Explain how the dioctyl sodium sulfosuccinate, DOSS, molecule might dissolve in water.
6. Explain how the dioctyl sodium sulfosuccinate, DOSS, molecule might dissolve in oil.
7. Explain how dioctyl sodium sulfosuccinate, DOSS, molecules might help break an oil spoil up into smaller oil droplets.
8. Write a complete 2-dimensional structural formula for dioctyl sodium sulfosuccinate, DOSS.
9. Write a condensed structural formula for dioctyl sodium sulfosuccinate, DOSS.
10. Write the molecular formula for dioctyl sodium sulfosuccinate, DOSS.

Standard Solutions

What is the difference between a primary standard and a secondary standard in volumetric analysis?
What substances can be used as a primary standard?
How do you make a standard solution?

All these questions are answered in AUS-e-TUTE's new tutorial on standard solutions.
Members should log-in and go to the Volumetric Analysis section on the index page, or,
follow the links from your Chemistry syllabus study guide.
Members will also find a game, test and exam as well as tutorial on this topic.
Teachers will find  a worksheet wizard which will let you make, and print off, a worksheet on this topic.

Not an AUS-e-TUTE Member?
There is currently a "free-to-view" tutorial at http://www.ausetute.com.au/titrstand.html

Borospherene

A molecule containing 60 carbon atoms in a cage-like spherical shape was first produced in 1985 and was called buckminsterfullerene, or bucky-ball. The structure is like a soccer ball, made up of 20 hexagons and 12 pentagons.
A bucky-ball is shown on the right. Each blue sphere represents a carbon atom, and each cream-coloured line represents a covalent bond between 2 carbon atoms.
One of the reasons that scientists are very interested in buckminsterfullerene is because of its ability to hold atoms of different elements inside the cage-like structure. This could enable bucky-balls to be used to deliver drugs in the body, or to store atoms such as hydrogen.

In 1991, scientists discovered that carbon atoms can also form nanotubes, and in 2004, sheets of carbon atoms just 1 atom thick known as graphene were discovered.

But can atoms other than carbon make these kinds of 3-dimensional networks at the nanometre level?

Researchers from Brown University, Shanxi University and Tsinghua University in China have shown that a cluster of 40 boron atoms forms a hollow molecular cage similar to a carbon buckyball. It's the first experimental evidence that a boron cage structure does indeed exist.
This boron cage, called borospherene, isn't quite as spherical as its carbon cousin. Rather than a series of five- and six-membered rings formed by carbon, borospherene consists of 48 triangles, 4 seven-sided rings and 2 six-membered rings. Several atoms stick out a bit from the others, making the surface of borospherene somewhat less smooth than a buckyball.

Because of the electron deficiency of boron, borospherene is likely to bond well with hydrogen. So these tiny boron cages could serve as safe houses for hydrogen molecules.

Reference:
Brown University. "Researchers discover boron 'buckyball'." ScienceDaily. ScienceDaily, 13 July 2014. .

Further Reading:
Graphene
Molecular Formula
Allotropes

Suggested Study Questions:

1. Write the molecular formula for buckminsterfullerene given the information in the article above.
2. How many covalent bonds does each carbon atom in buckminsterfullerene make?
3. Do you expect buckminsterfullerene to be soluble or insoluble in water? Explain your answer.
4. Draw a representation of graphene.
5. How many covalent bonds does each carbon atom make in graphene?
6. Do you expect graphene to conduct electricity? Explain your answer.
7. Write the molecular formula for borospherene based on the information provided in the article.
8. In the pictorial representation of borospherene given above, what do each of the following represent:
   • red spheres
   • yellow lines
9. In what ways are the structures of bucky-balls and borospherene similar?
10. In what ways are the structures of bucky-balls and borospherene different?

Dilution Factors

I've always thought that an understanding of dilution factors can make a Chemistry student's life a whole lot easier, but at the same time, always avoided teaching it (or indeed making reference to it) because of the muddle students make of it (thinking that every calculation involving a solution can be dealt with using dilution factor "formulae") .... and even worse, biology students always seem to have a desire to just "add volumes" together (even if the volumes are not additive!).

The new dilution factor resources are available to AUS-e-TUTE Members in the Members Only area (and teachers will find a worksheet wizard in the Teachers Area).

Not a member?
You can find out about AUS-e-TUTE Membership at  http://www.ausetute.com.au/membership.html

and you can join AUS-e-TUTE at http://www.ausetute.com.au/register.html

There is a free-to-view tutorial currently available at http://ausetute.com.au/dfactor.html

Capillary Action

Why does cola rise up a drinking straw?
Why does water creep up paper?
Why does a tee-shirt "soak up" sweat?

AUS-e-TUTE has a new set of Surface Chemistry resources for Capillary Action (also known as capillarity, capillary motion, or, wicking). AUS-e-TUTE Members can log-in to use the new tutorial, game, test.

Not an AUS-e-TUTE Member?
Find out what you're missing at http://www.ausetute.com.au/membership.html
and register for membership at http://www.ausetute.com.au/register.html
There is a free sample tutorial on capillarity currently available at
http://ww.ausetute.com.au/capillarity.html

Problem Solving in Chemistry

Chemistry students are expected to be able to solve chemistry problems.
On every exam paper, there will be an assortment of problems for students to solve.
Sometimes they do it well, sometimes they do it OK, and sometimes they do it badly.
Often, we give students time before exams to practice answering exam questions.
But how often do chemistry teachers actually explicitly teach problem solving skills?
Often we expect students to "follow our lead" when we demonstrate how to solve particular problems, but do we ever give them a good general framework that they could use to solve any problem they are likely to face in exams?
Most likely the answer is no.
"Surely, by the time students get to the senior years of high school they should be able to solve problems right?" I hear you ask.
While this is a reasonable expectation, the reality is that quite a few can't, just try reading the annual examiners reports and you will get a feel for the kinds of difficulties many students face when trying to solve problems.
So, I've spent some time doing some reading, quite a lot of thinking, and more typing than I'd like, in order to produce a framework for problem solving in chemistry.

You can see the results on the AUS-e-TUTE page on Problem Solving in Chemistry:
http://www.ausetute.com.au/stopgops.html

and a results-only demonstration of the problem solving process in action has been added to the bottom of the amended Dilution Calculations page:
http://www.ausetute.com.au/dilucalc.html

The problem solving page might seem like a lot of reading, but once your students become familiar with the process it is really very quick. It helps them identify potential difficulties BEFORE they actually start doing calculations, ensures they answer the question they were asked and that they check the answer to make sure it is reasonable.

If you happen to teach physics and/or maths as well as chemistry, the method can be applied to these subjects as well.

Because acronyms are useful, I've called this the StoPGoPS approach to problem solving, for reasons that will become self-evident when you read the problem solving page, and I've used a set of traffic lights as a visual aid to recall.

Please feel free to comment on the usefulness of this problem solving model.

Trans Fats

Some fats, such as polyunsaturated fats, are thought to be good for us.

They lower the "bad" type of cholesterol which has been linked to heart disease.

Other fats, such as saturated fats and trans fats, are considered to be bad for us because they increase this "bad" type of cholesterol.

Since the beginning of the 21st century, health authorities all over the world have been calling for the elimination of trans fats from commercially produced food products.

But what is a trans fat and where does it come from?

Go to the June 2014 issue of AUS-e-NEWS for the chemistry of Trans Fats.

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