Natural Environmental Process: "Rusting"

A layer of reddish cover the surface of the steel or iron-Rust.


Rusting, is oxidation of the metal to form a metal oxide.

Conditions for rusting:
Present of water and oxygen.

The corrosion of iron can be explained with theory of voltaic cell.
Process of Rusting:

First
Dents on the surface of iron is no longer protected and contact with water are the typically sites of iron loss. These sites is known as anodic regions and Fe undergoes oxidation donor 2 electron to form Fe2+ ion.

On the regions of high concentration of oxygen where near the water surface;Oxygen react with H ions and electron from Fe to form water. This region is so called cathodic region because oxygen is undergoes reduction.
Then the overall red ox reaction is completed but the rust still haven't form.

Next, the Fe2+ions form from the anodic region disperse through the surrounding of water and react with oxygen.

Finally
The rust is formed at some distance from the pit.

The following diagram show the process of rusting:

Situations that make the rate of rusting increases:

~At low pH value(high concentration of H ion)
~In contact with ionic solution.
~In contact with a less active metal (like Copper)
~The presence of corrosive agents, such as sea water, salt air, acids, acid precipitation, soils, and some sulfur compounds present in the atmosphere, which act as catalysts in the oxidation process.


Corrosion of iron and steel due to rusting is responsible for millions of pounds of damage each year. Rust does not firmly adhere to the surface of the metal allowing it oxide further. The oxide causes damage to the surface of the metal known as pitting which, over time, reduces these structural integrity of the metal.

Methods to protect steel or iron from rusting:-

Barrier methods: introduce a layer that prevent steel in contact with moiture and air .
Ex: a layer of grease, paint, plastic, or an unreactive metal, such as tin, copper, or chromium.
Sacrificial protection is the iron covered by more active metal (stronger reducing agent) such as zinc and magnesium which loss electron more ready than Fe.



Case:Eiffel Tower Maintance


The Eiffel is built by the cast iron, a material will last longer if it is painted regularly.


Maintenance on the tower includes applying 50 metric tons of three graded tones of paint every 7 years to protect the 200,000 square meters of iron lattice work from rust. The darkest paint is used at the bottom and the lightest shade at the top.Each repainting took time for 15 months with 25 painter and used up 1500 brushes. On occasion, the color of the paint is changed. The tower is currently painted to a shade of brown.


The 17th repainted- the application of an anticorrosion treatment lasts one year, so that the tower can stay open and continue to greet visitors.

Caffeine: Only Miracle in Coffee

The following show the 3D model and 2D molecules of caffeine structure:



Caffeine, also known as trimethylxanthine, coffeine, theine, mateine, guaranine, and methyltheobromine, is an alkaloid found naturally





One common source of caffeine is the coffee plant, the beans from which are used to produce coffee.


Coffee is a delicious and wholly natural product that contains several hundred different chemicals such as caffeine and that help to define its distinctive taste and aroma.

Caffeine in its pure form is the chemical standard for bitterness.

This is why coffee become one of the most drank in the world.

The most delicious and expensive coffee is Jamaica Blue Mountain Coffee:




The most easy available coffee is Starbucks Coffee:

Caffeine level in a cup of coffee:

It is very difficult to analysis the implications of caffeine in people because the quantities of caffeine in every cup of coffee is different.

One dose of caffeine is generally considered to be 100 mg. In theory, a single serving ( 150 ml) of drip coffee or one-half caffeine tablet would deliver this dose. In the real world, coffee varies considerably in caffeine content per serving, ranging from about 75 mg to 250 mg.

Caffeine's main pharmacological properties are: a stimulant action on the central nervous system with psychotropic effects and stimulation of respiration, a stimulation of the heart rate, and a mild diuretic effect.

After drinking a cup of coffee:

The chemical in our brain called adenosine which slow down nerve cell activity when we are sleepping is replaced by caffeine binds to the adenosine receptors. This cause the cell can not bind with adenosine ,the cells activity speed up. So that, person feel sleeplessness at night.

After that, the pituitary gland detects all this activity and thinking there is a emergency ready to happen, so stimulate the adrenal glands to produce adrenaline to increase our heartbeat rate, the liver release glucose into the bloodstream - provide extra energy to muscle cells for emergency action like running.

Then, person will feel excited, enjoyment and reinforcement.
All this effect can feel by a person who first time consuming a cup of coffee or rarely.


Coffee drink recipes:

Let DIY a cup of aroma coffee ... ...

latt'in lover
Ingredients:

16 ml Philibert Routin amaretto syrup
8 ml Philibert Routin cherry syrup
1 shot of espresso coffee
4 oz (125 ml) cold milk
Sliced almonds
Cherry

Method:Mix together the two syrups and the milk in a jug. Steam foam the mixture. Pour espresso into a 12 oz (350 ml) glass. Fill with steamed milk and stir. Garnish with the almonds and cherry

Recipes copy from: http://www.cafebar.co.uk/coffee_school/coffee_recipes/coffee_drink_recipes.aspx

Panadol: "Common Medicine in Every House"

Panadol is a common medicine for every houses.

Actually "Panadol" is a brand name. Panadol's medicine contains the ingredient of paracetamol alone.
What is paracetamol?

Paracetamol can described as 4-acetamidophenol, 4-hydroxyacetanilide or N-acetyl-p-aminophenol. The formula is as the following:

Paracetamol is white, odourless crystalline powder with a bitter taste. Pacacetamol is soluble in water, alcohol, acetone, glycerol, chloroform or methyl alcohol. It is insoluble in benzene and is stable but not in acids or alkaline situations.

Within all this properties, Panadol tablets are white in colour and came out with the Panadol soluble product.

Paracetamol is a medicine used for moderate pain such as headache, toohcare, sore throat, period pain, joint pain and rheumathic aches and pains.It also suitable medicine for fever with colds and flu.

There are many type of Panadol's product in the market now. Different product have their owm characteristic and function.

List of Panadol's poducts:

Panadol extend, Panadol tablet, Panadol ActiFast , Panadol soluble... ...

All the pakage of Panadol have stated the recommended dose, how to take it and the ingredient of paracetamol.

Recommended dose:
> Adult: 1-2 tablets of the 500mg Panadol for each dose

> Children(age 7-12): 1 tablet of the 500mg Panadol for each dose

Panadol can only take each dose at every 4-6 hourly.

Overdose!!!

It is very dangerous for paracetamol overdose: liver damage.

The symptoms does not seem and fatal when the person urgently sent to hospital.

Warning!

Before taking the Panadol, people should take a caution if their kidney and liver are not working properly, a heavy alcohol drinker and malnourised as paracetamol is a drug that will worse our kidney and liver.

Always remember avoid take this medicine with other medicine that contain paracetamol.

If you taking Panadol for headaches too often can make the headaches worse. So consult a doctor if your headaches become persistent.

Benefit?

Panadol is suitable for prenancy and breastfeeding mother. It benefit to the mother and not leave any risk to unborn baby.

But always inform or listen to advice of a doctor be4 using this medicine.

What Is Chemistry?

Chemistry is the study of the matter and its chemical and physical porperties.

Chemistry tends to focus on the properties of substances and the interactions between different types of matter, particularly reactions that involve electrons.

Matter that undergoes chemical and physical changes are associated with the energy cahnge.

Chemistry is present in our daily life...
Things that you can see, touch, eat, smell and etc... ...