Periodic Table update

 IUPAC has updated the periodic table.

Time to update yours .... https://iupac.org/wp-content/uploads/2022/05/IUPAC_Periodic_Table-04May22.pdf

IUPAC Periodic Table Challenge 2020

The IUPAC Periodic Table Challenge is back in 2020!

Select a level:

• Beginner
• Intermediate
• Advanced

Enter your details (your name will go on the certificate). If you enter the name of your school/institution, your school/institution will be in the running for an IUPAC Periodic Table poster signed by a chemistry Nobel Laureate.

Choose an element to be your avatar.

Answer 10 multiple choice questions about elements.

Score 60% or more and get a certificate.

So what are you waiting for?

Go to https://iupac.org/periodic-table-challenge/ now!

Naming Nitriles

How do you name a molecule like H-C≡N?
If you are an inorganic chemist you might call it:

• hydrogen cyanide (hydrogen name)
• hydridonitridocarbon (additive name)
• methylidyneazane (substitutive name)

If you are an organic chemist you might call it:

• hydrogen cyanide (functional class name)
• formonitrile (preferred IUPAC name)
• methanenitrile (substitutive name) 

The CN functional group at the end of a hydrocarbon chain results in a molecule that belongs to a class of organic compounds called nitriles. All nitriles contain a terminal CN group known as the cyano functional group.
AUS-e-TUTE has a new tutorial, game and test to help our members understand and apply IUPAC naming rules to nitriles. Members should log-in to use these new resources.

If you are not a member of AUS-e-TUTE you can access a "free-to-view" tutorial on naming nitriles at https://www.ausetute.com.au/namnitrile.html

Hydroxyacid or Carboxyalkanol?

So, you've learnt how to name organic molecules containing the OH (hydroxy) functional group, and, you can name molecules that have the COOH (carboxyl) functional group, the carbonyl functional group (C=O), and the NH₂ (amine) functional group.
Excellent!
But what happens when there are 2 or more different functional groups on the same molecule?
Can you still name it?
We can help!
AUS-e-TUTE has just added a new tutorial, game, test and exam to help you learn the IUPAC rules and confidently apply them to these sorts of molecules.
AUS-e-TUTE Members should log-in to use the new resources (under Organic Nomenclature).
If you are not an AUS-e-TUTE Member you can view the tutorial for free at
https://www.ausetute.com.au/nam2fung.html

Name and Formula of Inorganic Acids

There are systematic ways to name inorganic acids, however, for many acids no-one uses these systematic names because the "acid name" for these particular acids has been in use for a very long time. So, IUPAC recognises the "acid name" for a number of acids.
AUS-e-TUTE has just added a new tutorial, game, test, quiz and worksheet wizard, as well as a card game, to help you give the name and molecular formula of these acids. AUS-e-TUTE members should log-in to use these new resources.

If you are not an AUS-e-TUTE member, there is a "free-to-view" tutorial currently available at
https://www.ausetute.com.au/acidnames.html

Don't forgot to download our free "Inorganic Acid Names Card Games" when you visit!
(includes instructions for 3 games and a set of game cards).

Name and Formula of Inorganic Molecules

Non-metallic elements combine to produce covalent compounds, that is, molecules in which the atoms are held together by covalent bonds.
But do you know how to name these molecules using IUPAC recommendations?
Can you write the formula for these molecules using IUPAC recommendations?

AUS-e-TUTE has just added new resources on these topics.
AUS-e-TUTE members should log-in to access the tutorials, games, tests, exams, drills.
AUS-e-TUTE class and school group members also have access to the online quizzes.
Teachers registered with a class or school group can also access the worksheet wizards (instant worksheets, with answers, at the click of button!).

If you are not an AUS-e-TUTE member, there are two "free-to-view" tutorials currently available:

Naming Binary Inorganic Non-metallic Compounds

Molecular Formula of Binary Inorganic Non-metallic Compounds

IUPAC Name and Formula of Anions

How do you write the formula of an anion?
How do you use IUPAC nomenclature to name an anion?
AUS-e-TUTE has new resources to help you understand this and to help you apply these rules to writing formula and names of anions.
AUS-e-TUTE Members should log-in to use the interactive resources.
If you are not a member then you can access a "free-to-view" tutorial at
https://www.ausetute.com.au/anions.html

IUPAC Name and Formula of Cations

Naming chemical compounds can be a bit tricky. One of the biggest problems is that people started naming compounds before they understood what they were! And, the problem just gets bigger as we discover new classes of compounds.
Even naming simple binary inorganic ionic compounds (well ... salts!) can produce enormous headaches.
Well, we've started sorting through some of the mess, starting with a whole let new set of resources for writing the formula of cations and naming cations using the current IUPAC recommendations.
Members should log-in to AUS-e-TUTE to use the new resources, but if you are not a member you can go to the "free-to-view tutorial" at https://www.ausetute.com.au/cations.html

Omega-3 Acids Fight Cancer

Scientists at the University of Guelph have found that omega-3s from fish are better at preventing cancer than omega-3s from plants.

"Omega-3s" refer to omega-3 fatty acids which are a type of long-chain, polyunsaturated carboxylic  acid. Long-chain carboxylic acids are referred to as "fatty acids".
The three omega-3 fatty acids studied were: 

• α-linolenic acid (ALA) which is found in plant seeds and oils

• eicosapentaenoic acid (EPA) which is found in fish, algae and phytoplankton

• docosahexaenoic acid (DHA) which is found in fish, algae and phytoplankton

 The skeletal structural formula for α-linolenic acid is shown below:

 The IUPAC name of α-linolenic acid is (9Z,12Z,15Z)-9,12,15-octadecatrienoic acid. 
The carbon atom of the carboxyl functional group (COOH) is labelled as 1, the next carbon atom in the chain is 2, then 3, etc, up until we reach the last carbon in the chain, carbon 18. The parent hydrocarbon for this molecule is therefore octadecane, with a suffix added for the carboxyl functional group, so we have octadecanoic acid. 
Along the way we find 3 (tri) double bonds (en) at carbons numbered 9, 12 and 15, so we modify the name of the carboxylic acid in one of two ways:

• 9,12,15-octadecatrienoic acid

• octadeca-9,12,15-trienoic acid

The "Z" indicates the 3-dimensional geometry,  in this case the "Z" geometry equates to a "cis" geometry.
So why would  (9Z,12Z,15Z)-9,12,15-octadecatrienoic acid be called an omega-3 acid?
There is an alternative naming "system" (not IUPAC)  in which the first carbon atom is not labelled 1, but instead it is called "alpha" (α), and, the carbon atom at the end of the long hydrocarbon chain is called "omega" (ω). Then, the last carbon atom in the chain (omega) is labelled 1, and you start counting back towards the carboxyl functional group. If you do this, you will find that carbon 3 has a double on it, hence, (9Z,12Z,15Z)-9,12,15-octadecatrienoic acid is called an omega-3 fatty acid. The 3 indicates the position of the first double bond from the omega carbon atom.

The skeletal structural formula of eicosapentaenoic acid is shown below:

The IUPAC name for this molecule is (5Z,8Z,11Z,14Z,17Z)-5,8,11,14,17-Icosapentaenoic acid. 
There are 20 carbon atoms in the chain so the parent hydrocarbon chain is icosane, which is modified with a suffix because there is a carboxyl functional group, icosanoic acid.
There are 5 (pent) double bonds (en) located on carbons 5, 8, 11, 14 and 17, so the name of this molecule is either:

• 5,8,11,14,17-icosapentenoic acid

• icosa-5,8,11,14,17-pentenoic acid

Once again, the Zs in the name refer to the geometry (same as a "cis" geometry in this case).
Notice that, in the alternative naming "system" in which the last carbon atom in the chain is labelled "omega" and then you count backwards from this, we see that the first double bond encountered is on carbon 3, so this molecule is also referred to as an omega-3 fatty acid.

The skeletal structural formula below is that of docosahexaenoic acid:

This molecule has the IUPAC name (4Z,7Z,10Z,13Z,16Z,19Z)-4,7,10,13,16,19-Docosahexaenoic acid. 22 carbon atoms in the chain (docosa), 6 (hexa) double bonds on carbons 4, 7, 10, 13, 16, 19 and a carboxyl functional group: 4,7,10,13,16,19-docosahexaenoic acid or docosa-4,7,10,13,16,19-hexenoic acid. Zs indicate geometry (same as "cis" in this case).
Using the alternative numbering system, the first double bond occurs of the third carbon atom from the omega carbon atom (last carbon in the chain) so it is also classified as an omega-3 fatty acid.

While all three of these omega-3 fatty acids were shown to be effective in reducing the size of tumours in mice, however, higher doses of the plant-based α-linolenic acid was required to deliver the same impact as the omega-3 fatty acids found in fish (icosapentaenoic acid and docosahexaenoic acid)



Reference:

Jiajie Liu, Salma A. Abdelmagid, Christopher J. Pinelli, Jennifer M. Monk, Danyelle M. Liddle, Lyn M. Hillyer, Barbora Hucik, Anjali Silva, Sanjeena Subedi, Geoffrey A. Wood, Lindsay E. Robinson, William J. Muller, David W.L. Ma. Marine fish oil is more potent than plant based n-3 polyunsaturated fatty acids in the prevention of mammary tumours. The Journal of Nutritional Biochemistry, 2017; DOI: 10.1016/j.jnutbio.2017.12.011

Further Reading:
Introduction to naming organic molecules: http://www.ausetute.com.au/namctut1.html
Introduction to functional groups: http://www.ausetute.com.au/fungroup.html
Fatty acids: http://www.ausetute.com.au/fattyacid.html 
Structure and properties of carboxylic acids: http://www.ausetute.com.au/carboxyl.html
Molecular formula: http://www.ausetute.com.au/molecularformula.html
2-Dimensional structural formula: http://www.ausetute.com.au/structural2D.html
Condensed structural formula: http://www.ausetute.com.au/condensedsf.html
Skeletal structural formula: http://www.ausetute.com.au/skeletal.html
Cis-trans isomers: http://www.ausetute.com.au/cistranso.html 


Suggested Study Questions:

1. What functional group is common to all fatty acids? 
2. Define the following terms as they are used in chemistry:
   • saturated
   • unsaturated
   • monounsaturated
   • polyunsaturated
3.  Give the molecular formula for each of the three omega-3 acids in the article
4. The structural formula given in the article are referred to as "skeletal". What does this mean in chemistry?
5. Draw a 2-dimensional (full display) structural formula for each of the omega-3 acids in the article.
6. On the structural formula of each of the three omega-3 acids circle the:
   
   • carboxyl functional group in red
   • double bonds in blue
7. What features are common to three omega-3 acids in the article?
8.  In what ways do the the three omega-3 acids in the article differ?
9. You have probable heard about omega-6 acids. How do you think an omega-6 acid will be similar to an omega-3 acid?
10. How will an omega-6 acid be different from an omega-3 acid?
11. What is meant by a cis isomer and a trans isomer?
12. All the omega-3 fatty acids in the article are the cis isomers. Build a model, and draw, a trans isomer of one of the fatty acids.

Coral Killing Sunscreens

More than a year ago, a study involving marine scientists from Virginia, Florida, Israel, the US National Aquarium and the US National Oceanic and Atmospheric Administration, identified a common chemical component of sunscreens capable of damaging coral reefs.
This chemical is commonly known as oxybenzone and its structure is shown below:

This molecule has the systematic IUPAC name of (2-hydroxy-4-methoxyphenyl)(phenyl)methanone
Notice how every carbon atom (except that of the terminal methyl group, the carbon atom of the methoxy group) is involved in a double bond?
This kind of arrangement leads to some interesting properties. One of these properties is that molecules like this one are good at absorbing UV light. So, oxybenzone is added to products such as plastics, sunscreens, hairsprays, nail varnish and cosmetics like lipstick and mascara, as a UV filter.
Sunscreen lotion can contain between 1 and 10% oxybenzone.
Unfortunately, oxybenzone enters the water when people wearing sunscreens or other cosmetics decide to go for a swim. Researchers estimate that between 6,000 and 14,000 tonnes of sunscreen lotion are emitted into the waters of coral reefs each year.
The same property that makes it ideal as a sunscreen makes it a catastrophe for our coral reefs! Blocking UV light to baby corals causes growth deformities, and worse, the coral becomes encased in its own skeleton and dies.
In 2016, a study of Hawaii's sea waters found the oxybenzone concentration ranged from 0.8 to 19.2 µg/L. A previous study found that oxybenzone concentrations as low as 0.062 µg/L could harm the coral.
Hawaii's government asked swimmers, surfers and divers to avoid using sunscreens that contain oxybenzone as a measure towards protecting their reef.

Reference:
Hawaii targets sunscreens with oxybenzone 

Suggested Study Questions:

1. Draw a molecule of oxybenzone, and, locate and name each functional group. 
2. Give the molecular formula for oxybenzone.
3. Calculate the molar mass of oxybenzone.
4. Draw the 2-dimensional structural formula for oxybenzone.
5. Oxybenzone readily dissolves in ethanol. Explain how oxybenzone can dissolve in ethanol.
6. Oxybenzone does not dissolve in water. Explain why oxybenzone dissolves in ethanol but not in water.
7. Given the data in the article, calculate the mass of oxybenzone that could be emitted into coral reef waters each year.
8. Convert the following concentrations of oxybenzone to concentrations in parts per million
   • 0.062 µg/L
   • 0.8 µg/L
   • 19.2 µg/L
9. Convert the following concentrations of oxybenzone to concentrations in moles per litre (molarity)
   • 0.062 µg/L
   • 0.8 µg/L
   • 19.2 µg/L
10. Assume a 375 g tube of sunscreen lotion contains 10% by mass oxybenzone. Use the data in the article to calculate an "average" number of tubes of sunscreen that washed into the ocean each year. Justify your answer.

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

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

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

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