CHEMISTRY AROUND THE WORLD When we see something around us, we recognize that every single thing is chemistry. So certainly, for better live, we have to motivate ourselves to learn everything around us. "Green Education through Eco Chemistry."
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Green Education through Eco Chemistry
"Green Education" bertujuan untuk melancarkan peningkatan kualitas pendidikan bangsa melalui penerapan "Eco Chemistry", yaitu pembelajaran yang dilakukan dengan memanfaatkan segala sesuatu yang alami, ramah lingkungan, sehat, praktis dan ekonomis. Pembelajaran ini memerlukan motivasi diri, internal maupun eksternal dan kepedulian terhadap lingkungan hidup.
Ide ini muncul sejak dicanangkannya tahun 2011 sebagai Tahun Internasional Kimia yang bertepatan dengan peringatan 100 tahun Marie Curie menerima hadiah nobel sebagai ilmuwan kimia wanita pertama. Sedang pemikiran dasar terungkapnya ide ini disebabkan oleh masalah dunia yang sangat memerlukan perhatian, yaitu "Green House Effect" dan "Global Warming." Tindakan ini merupakan salah satu wujud partisipasi aktif penulis terhadap pelaksanaan program wajib belajar 12 tahun dan "Surabaya Eco School."
Penulis mengajak pembaca untuk menerapkan "Green Education" melalui "Eco Chemistry" dalam kehidupan sehari-hari. "Green Education" berlangsung seumur hidup (Long life Education), sejak janin dalam kandungan ibu hingga akan masuk ke liang kubur. Marilah dengan niat dan tekad yang kuat kita tingkatkan terus pendidikan diantara kita, terutama anak bangsa sebagai generasi penerus. Pendidikan ini dapat berlangsung Dimana saja dan Kapan saja.
Contoh penerapan "Eco Chemistry" dalam pembelajaran di SMA Negeri 16 Surabaya secara bertahap penulis terbitkan dalam bentuk artikel. Pembelajaran "Eco Chemistry" yang dimulai di sekolah, terus dilanjutkan secara bertahap ke masyarakat. Diharapkan melalui terobosan baru ini, yaitu penerapan "Eco Chemistry", masyarakat memahami dan menyadari bahwa kimia sangat berperan dalam kehidupan dan masa depan bangsa. Hal ini sesuai dengan slogan "International Year of Chemistry 2011" (IYC 2011), yaitu Chemistry: Our Life and Our Future" yang telah ditetapkan oleh PBB melalui UNESCO. Insya Allah tujuan pendidikan ini dapat tercapai secara optimal.
Web Blog Sejuta Guru Indonesia
Ini adalah Blog lamaku yang hingga saat ini digunakan oleh banyak guru, siswa, dan pihak lain yang memerlukan.
Saya juga memiliki Blog Baru lagi yang isinya mulai banyak dan artikel-artikelnya banyak yang berasal dari pertanyaan pengunjung dan permintaan artikel khusus.
Saya akan berupaya untuk mempublish artikel-artikel baru di kedua Blog ini, termasuk blog-blog saya yang lain. Insya Allah tiap hari saya tetap dapat meluangkan waktu untuk menulis artikel, baik tentang kimia, pendidikan seumur hidup, Eco School, kesehatan, dan artikel lainnya.
Semoga kebiasaan menulis ini tak pudar oleh apapun, walau memasuki usia senja. Berbuat yang terbaik untuk anak bangsa begitu indah, marilah bersama cerdaskan bangsa.
Terima kasih
Silakan Berkunjung di http://etnarufiati.guru-indonesia.net
Wednesday 30 September 2009
ENTHALPY CHANGE
DETERMINING ENTHALPY CHANGE
Explain this picture clearly. Look at the calorimeter, there is a metal in the water.
Suggest the metal used in this reaction, find an experimental data and then determine the enthalpy change in kJ/mol.
CALORIMETRY TASK
Your task is explaining the use of this equipment, plan an experiment by using this equipment. Choose a certain reaction, for example neutralisation reaction between strong acid, HCl(aq) and strong base, NaOH(aq).
Your explanation including how to use termometer; why there is a difference between the experimental data from scientist and your result.
Monday 28 September 2009
DIPOLE INDUCED DIPOLE FORCES
According to this evidence, by distorting the distribution of electrons around the argon atom, the polar HCl molecule induces a small dipole moment on this atom, which creates a weak dipole-induced dipole force of attraction between the HCl molecule and the Ar atom.
DIPOLE FORCES
In the example on the left, hydrogen chloride is a polar molecule with the partial positive charge on the hydrogen and the partial negative charge on the chlorine. A network of partial + and - charges attract molecules one of another.
IONIC FORCES
In an ionic bonding, there is an ionic force. This force is commonly called electrostatic force (Coulomb).
Each Na+ ion and Cl- ion attracts one of another, so that they forms a Crystal.
Although there is a repulsion between inner electrons of Na+ and outer electrons of Cl-, the ionic force is much stronger than the repulsion.
The ionic force is much stronger than the molecular force, so boiling point and melting point of ionic compounds are higher than covalent compounds. The last force will be discussed later.
INDUCED DIPOLE FORCES
Forces between non-polar molecules are the weakest of all intermolecular forces.
In the non-polar molecules there are 'Temporary dipoles" which are formed by the shifting of electron clouds within molecules. These temporary dipoles attract or repel the electron clouds of non-polar molecules.
The temporary dipoles exist for a fraction of a second, so a force of attraction exist for that fraction of time. The strength of induced dipole forces depends on how easily electron clouds can be distorted. Atoms or molecules which have many electrons are more easily distorted, because these electrons are far from their nucleus.
Okay, please explain about intermolecular forces in iodine molecules as shown in the picture. Give the reason why in the iodine molecule, atom that has the negative temporary pole is bigger than atom with positive temporary pole,
HYBRIDIZATION PROBLEMS
1. Write the electron configuration of this atom in the ground state.
2. Which atom has this electron configuration?
3. Why this hybridized orbital called sp2?
4. Give an example of the molecule which has hybridized sp2 orbitals.
5. Apply your understanding of hybridization to another example, for orbitals sp.
6. Explain hybridized sp3 orbitals for ammonia and water.
7. Compare the molecular geometry of methane, ammonia, and water.
8. Explain the reason why methane, ammonia, and water have different molecular shapes, although have the same hybridized orbitals.
Sunday 27 September 2009
HYBRIDIZATION
Friday 25 September 2009
THE TYPE OF MOLECULAR GEOMETRY
Wednesday 23 September 2009
THE AXE SYSTEM
GEOMETRY OF WATER
Please explain both pictures. For the first picture, explain according to the order of the picture. Similarly, explain the second picture.
Don't forget to compare geometry of the 3 compounds. For doing this, you can draw all the 3 compounds.
ELECTRON PAIR GEOMETRY AND MOLECULAR GEOMETRY
Electron pair geometry is determined by the number of electrons around the central atom, both bond pairs (BP) and lone pairs (LP). These geometry is a domain electrons postulated by VSEPR.
This domain is as a result of minimizing the repulsions between electron pairs. Remember, in the VSEPR theory, the repulsion of BP - BP < BP - LP < LP - LP. In practise, the balloon for LP is bigger than BP, because the repulsion of LP is stronger than BP.
Because methane has 4 BP, the strength of repulsion is the same, its molecular geometry is also tetrahedral, as same as its electron pair geometry. Ammonia has 3BP and 1 LP, the repulsion of LP - BP > BP - BP. That is why, its molecular geometry is trigonal pyramidal. So the molecular geometry differs with its electron pair geometry. Please think about water molecule and compare its geometry with methane and ammonia.
Monday 21 September 2009
RADIUS OF ATOMS AND IONS
Thursday 17 September 2009
HYDROGEN MOLECULES
Hydrogen atom is not stable. It can stable if it has 2 electrons (duplet rule). That is why, hydrogen gas consist of 2 atoms per molecule (diatomic molecule). When two hydrogen atoms are closely, the electrons are attracted by each hydrogen's protons, and share one of another to form an electron pair. As a result, there is a non polar covalent bond of hydrogen molecule, H2. The non polar bond is occurred, because these two hydrogen atoms have the same ability of attraction.
ORBITALS PROBLEMS
Do you remember these orbitals?
These orbitals are very important for elements in the A (main) groups.
1. How many orbital(s) is (are) in the s sub shell?
2. How many orbitals are in the p sub shells?
3. Do you remember, how many sub shells are maximum in an atom?
4. There are atoms that only have a s orbital. Whose are these elements?
5. Write the electron configuration of those elements.
6. There are 18 elements whose have s and p orbitals. Write the electron configuration of these elements.
7. What is the difference between px, py and pz orbitals?
8. What is the difference between 1s and 2s orbitals?
IONIC COMPOUNDS PROBLEMS
This task is about writing the chemical formulas of ionic compounds.
the numbers above periodic table at each group are the oxidation number of atom in their compounds. Remember, if the atom an element, the oxidation number is zero.
For ionic compounds, the oxidation number is the charge of the cations and anions.
Covalent compounds consist of atoms rather than ions, because there is an electron shared. The oxidation number indicated the number of electron shared (bonded electron pairs, BP). The minus sign indicates that the BP electrons is closely to the atom which has greater electronegativity. This discussing only focuses on the ionic compounds.
1. Write formula of compound between berilium and fluorine.
2. Find 10 (ten) formulas of ionic compounds.
3. Predict which compound from no. (2) has highest boiling point and give the reason.
4. Predict which compound has lowest boiling point and give the reason.
EXCITED STATE OF ELECTRON
An electron of an atom, from the ground state position can move to the high energy level, if there is an absorption of photon. The energy of this electron will increase and energy level will also increase, higher than before. This electron move to the high energy level, the next level. In this new position, we call as an excited state. However, this electron is not stable, because the energy immediately release from the electron. At the same time, this electron go back to the initial level, that is the ground state position. The energy changes become a spectrum.
ELECTRON SHELLS
Okay, we discuss now. The picture shows electron shells of some elements that outer shells are not filled.
There is a possibility of these elements react with other elements, because they are not stable.
For stability, the number of electrons in the outer shell should be 2 electrons if it is closely to the helium atom (duplet rule) and 8 electrons if it is closely to the other inert gases (octet rule).
Look at a sodium atom. There is an electron in the outer shell, so if it reacts with a chlorine atom, it will loose the outer electron and it will form sodium ion, Na+. A chlorine atom, Cl will gain electron and form Cl- ion which has 8 electrons in the outer shell. Now Na+ is also has 8 electron in the outer shell (from the inner shell ). Both Na+ and Cl- now become stable. These ions attract one of another; as a result, these form NaCl(s) as a crystal. Na and Cl are chemically reactive.
HYDROGEN BONDING
Remember the intermolecular forces between HCl molecules. Why does the force between H2O molecules is stronger than HCl molecules?
You have to think the electronegativity of O and Cl. The electronegativity of oxygen atom is greater than chlorine atom, so that H2O molecules are more polar than HCl molecules.
How about fluor and nitrogen atoms? Electronegativity of Fluor atom is greater than oxygen atom and oxygen atom is greater than nitrogen atom. EN F> O > N. Are these elements have a hydrogen bonding in their compounds with hydrogen atoms? Certainly yes, they are. Because all these elements have the greatest electronegativity. Please think about HF and NH3, and alcohol molecules.
AQUEOUS SOLUTION
Wednesday 16 September 2009
PERIODIC TABLE OF ELEMENTS
You can make more than one copy, yeah ... it like a card, an ID card. Remember, this card is the key of chemistry.
FIRST IONIZATION ENERGY
ATOMIC RADIUS GRAPH
PERIODIC PROPERTIES TASK
Please use your logical thinking in doing this. Firstly what do you want to explain; secondly ...; and what will you do next. Then finally ....
If you don't know the order, its okay, just explain one by one; and then please think about the relationship between the properties you have explained. Think about cause and effect; so you will realise which one come first.
The paragraphs you have to write is about 250 words. Is it okay?
ELECTRONEGATIVITY TASK
What is the meaning of electronegativity?
Why the arrow of increasing electronegativity is different with increasing atomic radius?
So your task is, write paragraphs about 2oo words to clarify these periodic properties of elements. Don't forget to include explanation which element is the most electropositive one and which element is most electronegative. What the effect of these properties are.
ATOMIC RADIUS
ATTRACTION AND REPULSION IN IONIC BOND
Na(2,8,1) + IE --> Na+(2,8) + 1e
Cl(2,8,7) +1e --> Cl-(2,8,8) + EA
However, there is a slightly repulsion of the inner electrons of Na+ and outer electrons of Cl-.
Attraction of different charges and repulsion of electrons are occured among all Na+ ions and all Cl- ions, then they are closely together and form a cristall. The ratio of Na+ and Cl- = 1 : 1. The chemical formula of this compound is named emphirical formula, that is NaCl.
When barium ions, Ba2+ combine with Cl- ions, the formula is BaCl2, because the ratio of Ba2+ and Cl- = 1 : 2. Ba2+ + 2Cl- --> BaCl2.
MOLECULAR SHAPES TASK
Make 3 dimension shapes, if possible use different balloon for different atom. Firstly you can make a linear shape. Please give an example of each shape. For example : hydrogen molecule, H2 is linear. Make a table to show each molecule has certain shape. Complete your table with Lewis structure, determine bonding pair (BP) and lone pair (LP) electrons. Firstly think about symmetrical shapes, then unsymmetrical shapes. Mention about their molecular polarities, polar or non polar molecules.
Tuesday 15 September 2009
WATER BUBLES
Sometimes, when we look at a glass of water, there are bubles in the water. What do the bubles? Where are the bubles come from?
If we discuss about pure water, so the glass only consists of water molecules. In this water, sometimes we see bubles. These bubles are water molecules. This is happening, because there is an amount of energy from the environment arround water, absorped by water molecules. The kinetic energy of these molecules are greater than before, they move faster than the others. That is why, there are bubles, because these molecules make holes in the water for their movement. These molecules, at that time, change into a gasous state.
We can conclude that the bubles are water gas in the water liquid. this evident will disappear when the kinetic energy of molecules changes into their basic condition. The water gas changes into water liquid. However, the bubles will appear again sometimes if there is an energy transferred from environment to the system.
Monday 14 September 2009
WATER COVALENT BONDING TASK
You have to choose the best sentences which have a full meaning and short. Don't make it to long, because you will loose the relationship between concepts.
The paragraphs move from general to the specific concepts, from concreate to abstract theories.
Please try, you have to develop your writing step by step gradually, OK? So do it.
POLAR COVALENT BONDING TASK
Students, develop your thinking to the next bonding, that is polar covalent, as seen in the picture.
Before explaining this bond, firstly distinguish between polar and non polar covalent bonds. It is about polarity of bonding. The bond of H2 and Cl2 are different with the bond of HCl. The first are molecules of elements, on the other hand, the last is a molecular compound.
In writing the paragraphs, mention about electronegativity, the position of bonding electron pair (BP) between H - Cl, and the effect of this BP.
OXYGEN MOLECULES TASK
The next concept is the bond of oxygen molecules. Paragraphs that you have to write consist of Lewis structure, octet rule, non polar covalent bond, and double bond.
Firstly concern with oxygen molecules, then draw a conclusion.
After that, move on another example of non polar bond, such as nitrogen. Be careful, remember that valence electron of nitrogen atom is different with oxygen atom, so the type of non polar bond is also different.
Draw a diagram of nitrogen, similar to the diagram of oxygen in the picture.
NON POLAR COVALENT BONDING TASK
After you learn quite a lot about an ionic bond, now think another bond, that is a covalent bond.
Look at the picture, the simplest example is a hydrogen molecule. Compare this bond with ionic bond, such as in table salt, NaCl.
Is there any electron transfer in the bond between hydrogen atoms? Are you sure there is no electron transfer at all? What is the reason? Hydrogen is a non metal, so the bond is really different with NaCl, because sodium is a metal. Its OK, good point.
As before, your task is, make paragraphs which consist of clear explanation about the bond oh H2 molecules. Don't forget to mention Lewis structure, duplet rule, single covalent bond, and non polar covalent bond, including the reason of each clarification. Then apply this concept to another similar molecule, such as chlorine molecules.
RUST FORMATION TASK
Similarly, do this task based on the diagram, as same as the previous task about ionic compounds.
This is the process of rusting that is very often occurred in the daily life.
Be careful, although iron is a metal from the VIIIB group, its oxidation number are +2 and +3.
So that, don't draw all valence electrons of iron, just the number of electrons used in the process.
Draw a conclusion after finishing your explanation.
IONIC COMPOUNDS' FORMATION TASK
POSITIVE IONS TASK
NEGATIVE IONS TASK
Similar to the above explanation, develop your concepts to compare halogen elements, from fluorine to iodine. OK, please keep learning with always relax, serious, and success.
LABORATORY ACTIVITY TASK
BOILING POINT OF WATER
Sunday 13 September 2009
PH OF ACID SOLUTION TASK
The equipment is called a pH meter.
Make a plan for doing this and write down the data from the above observation. In the report, write the solution you use. There are two set of solutions, first from the calculation of concentration, use HCl(aq) and the other set, use solution from the kitchen.
YELLOW - BLUE SOLUTION TASK
PRECIPITATION REACTION TASK
Saturday 12 September 2009
CHEMICAL REACTION TASK
ACID - BASE TASK
CORROSION
LEMON SHELL GAME
What is she doing with the lemon. Help she to make the plan and make a report of this observation. Your report should be included title, propose, prediction, equipments, substances, table for recording data, discussion, and conclusion.
You can also make a suggestion for doing another reaction similar with this by using other materials in the kitchen.
Suggest an experiment in the chemistry laboratory, concerns with this type of reaction.
Finally, think about this type of reaction and make a description about this.
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