Organic Chemistry is the Chemistry of Carbon Compounds. Several millions organic compounds are known compared to no more than 100, 000 compounds that contain no carbon. There is, however, a small number of carbon compounds (e.g. CO, CO2, Metal Carbonates) that are not classified as organic.

The vast number of organic compounds reflects the exceptional ability if carbon to form covalent bonds with other carbon atoms to form chains, branched chains and rings structures. Straight chain compounds are called Aliphatic Compounds and ring compounds are called Cyclic Compounds.

In Organic Compounds, Carbon always has a valency of four. Apart from carbon, a small number of other elements is widely found in organic compounds. The most important of these elements are Hydrogen, Oxygen, Nitrogen, Sulphur and the Halogens.

Hi Avid readers of this Chemistry website,

Good to see you visiting this website and wanting to learn more about chemistry. I have been less active here for the last 2 weeks as i was busy with the GCE ‘O’ Level Intensive Chemistry Bootcamp program for a special group of students in Singapore. If you are one of the students in the Bootcamp, Give yourself a HIGH-FIVE!!! for being so committed to learn more about Chemistry Phenomenons, Tips and Strategies.

Today is the 2nd day of the Chemistry Intensive Bootcamp and i am enjoying it more and more. These special group of students which have committed 5 days of their holiday to spend time with us, in order to learn more and improve their grades in Chemistry. They have been AWESOME! I congratulate their attitude and energy in making the bootcamp so interesting and fun!

Yesterday, i was going through the Chapter on BONDING in the Bootcamp, and lots and lots and lots of examples were shared and many analogies were given. One of those we mentioned is DIAMOND, a giant macromolecule. We all know diamond, a part of woman’s life some say. 

 (Image by theappraiserlady)

Diamond is one of the hardest material on earth. It is not easily stretched, bent or worn out. Diamond exists as a solid in nature and has high Boiling Point and Melting Point. Melting point of diamond is in fact 3500 degrees Celsius. Diamond does not conduct electricity and is insoluble in water (of course not soluble, imagine your few thousands dollars diamond dissolve in water and you get nothing!!??)

Diamond has the above physical properties because of its chemical structure. It has all the typical properties of a Giant Covalent Molecule. A crystal of diamond contains millions of Carbon (C) atoms joined together by strong covalent bonds. Each carbon atom is bonded tetrahedrally to 4 other Carbon atoms. A lot of energy is required to break these strong covalent bonds, and this explains why diamond is so hard and difficult to melt. All the valence electrons in C atoms are used for bonding in diamond, and no free electrons to move around. Thus, diamond cannot conduct electricity.

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Besides uses in Gemstones in Jewellery (Diamond Ring, Pendant, Necklace, etc), diamonds are also used at the Tips of drills and other cutting tools. They are used for drilling, grinding and polishing hard surfaces.

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How many of you have applied a cold pack on your forehead before when you have a severe headache? Or perhaps you are a sportsman/woman that has used cold packs for your joints and muscles before. It certainly helps to relieve the pain isn’t it? But have you ever wondered how it works?  It is in fact Chemistry in actions!

Some cold packs contain chemicals which takes in heat when they react. This is why cold packs have a cooling effect on their surroundings, i.e. cooling effect on our forehead or our body muscles.

This phenomenon is due to the reactions that takes in and give out heat, and we call it formally as Energy Changes in Basic Chemistry studies.

 Ammonium salts such as ammonium nitrate (V) dissolve in water with the absorption of heat. This example of a spontaneous endothermic reaction is the basis of those commercial product you get at pharmacy, an Ice Pack that doesn’t have to be kept in the freezer. Cool huh!!!??

These ice packs contain a small quantity of ammonium nitrate (NH4NO3) or ammonium chloride (NH4Cl), which is separated from a sample of water by a thin membrane.. When the pack is struck with the palm of our hand, the membrane is broken, and the salt dissolves in the water.

NH4NO3(s) + H2O(l) –> NH4+(aq) + NO3-(aq) 

Enthalpy Change = 25kj/mol

or

NH4Cl(s) + H2O(l) –> NH4+(aq) + Cl-(aq)

Enthalpy Change = 20kj/mol

Because the reaction is Endothermic (+ve Enthalpy change), it absorbs heat from its surroundings, and the ice pack (which is the plastic membrane) can get cold enough to treat minor athletic injuries and headache.

More cool stuff about chemistry-related phenomenons will come soon. Stay Tuned!

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During the process of making cake, there is an important chemical reaction that is involved that determines if your cake will rise, aka, if your cake will look really like a “cake” – all puff up!

This is due to the chemical reaction between the Baking Soda (which contains Sodium Hydrogencarbonate) and the acid, to form carbon dioxide (CO2):

Sodium Hydrogencarbonate + Acid -> Sodium Salt + Carbon Dioxide + Water

Baking soda and the acidic component such as youghurt, lemon juice, vinegar or sour cream must be added and mixed into the pastry mix. Carbon dioxide is then released by the reaction, but gets trapped in the mix, and causes the cake to rise. This reaction produces your light and delicious pastries.

NEWater, Singapore’s high-quality reclaimed water, shone again on the world stage when it clinched the title “Environmental Contribution of the Year” at the Global Water Awards 2008 ceremony on Monday night in London.

This is the second award received by PUB, Singapore’s national water agency, from the award organiser, Global Water Intelligence (GWI). In 2006, PUB was named the Water Agency of the Year in Dubai.

You may first wonder how come this article is being posted in this Chemistry Blogsite?

• 1st Reason – I am proud as a Singaporean that a Singapore 1st – kind of project has gotten its deserved recognition

• 2nd Reason -Proces in NEWater is in fact what you are learning right now in Purification &  Separation chapter

The production of NEWater essentially consists of 3 main steps:

1. Use of microfiltration/ultrafiltration to filter out suspended solids, colloidal particles, disease-causing bacteria and some viruses. The filtered water that goes through the membrane contains only dissolved salts and organic molecules. (more…)

(Image by Eff Bee)

In the Chapter on Acids & Bases, we learned that Magnesium Hydroxide Mg(OH)2, an Basic Oxide is used to make toothpaste. 

After each meals, there will certainly be a significant amount of food substances that are stuck in-between our teeth. Overnight, bacteria in these food substances will secrete acids that will corrode our teeth and causes tooth decay. Magnesium Hydroxide(an Basic Oxide) has the basic properties and will neutralize the acids between the teeth to form neutral salt and water, which is gentle to our teeth. Simple concepts isn’t it.

This post i will talk about something more interesting in ‘Striped Toothpaste’.

Q) How do they get the stripes in the toothpaste?

Answer is easy. The manufacturer load toothpaste tubes from the flat end with parallel layers of paste and when you squeeze, the layers pass through the nozzle as stripes. According to Discovery Channel Documentaries, manufacturers used to put red paste (which is the stripe) in first. Then they would add the white paste on top. As you squeezed, the white paste would push through an inner tube, and be joined by the red coming through holes in the tube near the nozzle.

How about a little bit more on the brief history about Toothpaste:

• 1st known tooth powder was used in Egypt around 5000BC and included egg-shells and ox hooves
• Early toothpastes had ingredients such as dried animal parts, honey and powedered charcoal
• Europeans didn’t use toothpaste until 1800s and it contained chalk and pulverised brick
• Dr. Washington Sheffield invented the Toothpaste Tube in 1892
• Striped tootpaste was invented in England nearly 50 years ago

Amazing isn’t it??

 (Image by Transguyjay)

Just a few weeks ago, one of my current student under my Chemistry Coaching wings suddenly asked me to explain more about Nanotechnology when we came across a question on Fullerene (commonly known as BuckyBall) which signifies the entrance into the area of Nanotechnology. This has intrigued me to share more with my avid readers (mostly students).

The strength of small is huge, or that is what one ought to say about the new revolution called Nanotechnology. And why not! Nanotechnology, a new science which deals with atoms a few nanometres large, has the potential to make scientific strides across industries and impact mankind (more…)