Branches of Chemistry together with the insight

Branches of Chemistry together with the insight

TOPICS: Branches of Chemistry Along with the insight

 

Branches of Chemistry together with the insight

 

The chemistry was introduced around the year 3500 BC, in Ancient Egypt already practicing chemical reaction, in how to make wine and embalming. In the 4th century BC, the Greek philosophy that Democritus and Aristotle tried to understand the essence of the material. According to Democritus suggested that all matter is composed of tiny particles called atoms, whereas according to Aristotle, matter is made of four types of elements, namely: soil, water, air and fire. In medieval times (years 500-1600), which was pioneered by chemists Arabic and Persian. The chemistry leads to practical terms with it produces various kinds of substances such as alcohol, arsenic, zinc iodide acid, sulfuric acid and nitric acid.

Pharmaceutical chemistry learn about the manufacturing of drugs

Name of chemistry was born, from the Arabic word (al-Kimiya = change material) by Arab scientists Jabir ibn Hayyan (700-778 years). At the beginning of the 18th century, the term Modern Chemistry pioneered by the French chemist Antoine Laurent Lavoisier (1743-1794 years) who successfully argued the law of conservation of mass. In 1803, a British chemist named John Dalton (years 1766-1844) proposed the theory of the atom for the first time. Since then, the chemistry continues to grow rapidly until today.

Branches of Chemistry

Chemistry is the central science. The chemistry is grouped into branches of chemistry that includes:

Chemical analysis is a branch of chemistry that studies on the analysis of chemicals contained in a product.

Physical chemistry is the chemistry branch the focus of study in the form of energy that accompanies the determination of chemical reactions, physical properties of substances as well as changes in the chemical compound.

Organic chemistry is a branch of chemistry that studies the chemicals found in living things.

Inorganic chemistry is the branch of chemistry that is the opposite of organic chemistry; studying inanimate objects.

Environmental Chemistry is a branch of chemistry that studies on everything that is happening in the environment, particularly with regard to environmental pollution and ways to overcome them.

Chemistry Core (radiochemistry) is the branch of science that studies the chemistry of radioactive substances.

Biochemistry is a branch of chemistry that is very closely related to the biological sciences.

Food Chemistry is a branch of chemistry that studies how to improve the quality of foodstuffs.

Pharmaceutical Chemistry is a branch of chemistry that focuses its study in the form of research and development of materials containing the drug

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Dalton's Atomic Theory

Dalton's Atomic Theory

TOPICS: Dalton's Atomic Theory

 

Dalton's Atomic Theory

 

Today the word atom never mind very often we hear. But the birth of the concept of atoms requires a very long time, more than 2000 years. After his birth, still needed several centuries to finalize this concept. Atoms are initially we consider to be a solid ball that hard, now it turns out we understand as a cloud of matter is complicated.

In the 5th century BC, two Greek philosopher Leucippus and his pupil Democritus, stroll along the Aegean coast. Leucippus take his students to ponder something: "Is not the sea that seems to be continuously composed of small grains such as sand that lay on the beach? From a distance the sand looks continuous but close observation shows the sand composed of fine granules ".

Democritus who lived between the years 470 to 380 BC developed the idea of ​​the teacher. He stated that the matter is composed of smallest particles called atoms (a = not, Tomos = split). He believes that the atoms of different elements have different shapes and sizes. Water has the form a smooth ball that was cool while having the form of a sharp fire so hot. At that time, the Greeks believed that there are four elements that make up nature, namely earth, water, fire, and air. Nevertheless, thought Democritus did not attract people for 2,000 years because they have an addiction theory that matter is continuous.

In about 1779 a French scientist, Antoine Laurent Lavoisier, experiment carefully, namely mercury and the metal heats the air in a sealed tube. From these experiments he concluded that "in any chemical reaction, mass quantities of substances before and after the reaction is the same". This conclusion was later known as the Law of Conservation of Mass. Twenty years later, another French scientist who settled in Madrid, Joseph Louis Proust formulated a law called the Law of Comparative Keep reading: "Comparison of mass elements that compose a substance always remains".

To explain these two laws, a high school teacher of English, John Dalton, evoke memories of people about a term that has been forgotten that the atom. Dalton promoted his new theory of the atom through his book entitled New System of Chemical Philosophy. Beads of Dalton's atomic theory is as follows.

1. The material is composed of the smallest particles called atoms.

2. Atoms can not be subdivided into smaller particles.

3. The atoms of an element have the same nature and mass.

4. Different elements have atoms of different mass and properties.

5. The chemical reaction is the splitting or merging or rearrangement of atoms.

So it is clear now how Dalton's atomic theory capable of explaining both the above theory. In regard to the Law of Conservation of Mass, a chemical reaction just involve the rearrangement of atoms reactant into reaction products, so the mass number should remain the same. Or in other words, during the reaction the atoms are not created and destroyed. In regard to Comparative Law Still, a compound formed or composed of different types of atoms with a certain ratio so as to have a mass ratio always remains.

However, that does not mean Dalton's atomic theory has been perfect. Atoms in the form of solid ball of course not able to explain why a particular solution is electrolyte alias can conduct electricity. In fact, some parts of this theory is proven wrong.

Scrutiny began late 19th century until the early 20th century, drove the experts to the conclusion that atoms can be broken down into particles smaller. Subatomic particles are positively charged protons, neutral neutrons, and electrons are negatively charged. Thus points to the 2nd of this theory wrong.

Atom has a number of specific protons and electrons. But the atoms of the same element can have different numbers of neutrons. This causes the atoms of the same element may have different masses. These are called isotopes. This proves that point all three of Dalton's atomic theory is also wrong.

Apart from the various errors in his theory, Dalton has laid the foundations of modern atomic theory. This theory is built on a variety of experimental data that had been done by other experts such as Lavoisier and Proust.

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The reaction equated with Method Ping pong

The reaction equated with Method Ping pong

TOPICS: equalizes Reaction Methods Ping Pong

POSTED BY: NANDASANJAYA FEBRUARY 12, 2016

 

The reaction equated with Method Ping pong

 

Source: https: //ilmukimia.wordpress.com

Known ping pong method because the process of equalizing our reactions as if they were playing ping pong, namely filling coefficient of one segment and then move to other segments continuously until all the compounds gain coefficient. Consider the following steps.

Balance the reaction: KMnO4 + MnCl2 + Cl2 → HCl + KCl + H2O

1. Give the elements that exist only on one of the compounds on the left and the right side.

KMnO4 + MnCl2 + Cl2 → HCl + KCl + H2O

2. Start by giving the coefficients on compounds that have marked the element most numerous and most indexed. In this example, we will start from KMnO4 because these compounds have a marked element of the index is the most widely and most (4 to O atoms). KMnO4 given a coefficient 2 (1 is fine).

2 KMnO4 + MnCl2 + Cl2 → HCl + KCl + H2O

3. Balance the atoms marked on the left and right.

a. Give coefficient 2 on MnCl2 and KCl to equalize Mn and K.

2 KMnO4 + HCl → 2 MnCl2 + Cl2 + 2 KCl + H2O

b. Balance the O atom to give the coefficient 8 in H2O

2 KMnO4 + HCl MnCl2 + Cl2 → 2 KCl + 8 + 2 H2O

c. Balance the H atoms to give a coefficient of 16 on HCl.

2 KMnO4 + 16 HCl MnCl2 + Cl2 → 2 KCl + 8 + 2 H2O

d. Balance the Cl atom to give the coefficient 5 in Cl2.

2 KMnO4 + 16 2 MnCl2 HCl → Cl 2 + 5 + 2 KCl + 8 H2O

Often the "ping pong game" is not going smoothly until all the compounds has a coefficient. Sometimes a series of coefficients Award interrupted halfway. Consider the following cases.

Case breaking game 1

Balance the reaction: K2Cr2O7 + SnCl2 + HCl → CrCl3 + SnCl4 + KCl + H2O

1. Give the elements that exist only on one of the compounds on the left and the right side.

K2Cr2O7 + SnCl2 + HCl → CrCl3 + SnCl4 + KCl + H2O

2. Start by giving the coefficients on compounds that have marked the element most numerous and most indexed. In this example, K2Cr2O7 given a coefficient of 1.

1 K2Cr2O7 + SnCl2 + HCl → CrCl3 + SnCl4 + KCl + H2O

3. Balance the atoms marked on the left and right.

a. Give coefficient 2 on CrCl3 and KCl to equalize Cr and K.

1 K2Cr2O7 + SnCl2 + HCl → 2 CrCl3 + SnCl4 + 2 KCl + H2O

b. Balance the O atom to give the coefficient 7 in H2O

1 K2Cr2O7 + SnCl2 + HCl → 2 CrCl3 + SnCl4 + 2 KCl + 7 H2O

c. Balance the H atoms to give a coefficient of 14 on HCl.

1 K2Cr2O7 + SnCl2 + 14 + HCl → 2 CrCl3 SnCl4 + 2 KCl + 7 H2O

4. So far the "game of ping pong" we must stop. Still there are two compounds that have not been given a coefficient, which is SnCl2 and SnCl4. Both should have the same coefficient, for example a.

1 K2Cr2O7 + a SnCl2 + 14 + HCl → 2 CrCl3 a SnCl4 + 2 KCl + 7 H2O

To calculate the value of a, consider the Cl atom. The number of Cl atoms on the left and the right should be the same.

2a + 14 = 2 × 3 + 4a + 2 × 1

2a +14 = 4a + 8

a = 3

Thus the end result of the "game" we are:

1 K2Cr2O7 + 3 SnCl2 + 14 HCl → 2 CrCl3 SnCl4 + 2 + 3 + 7 H2O KCl

Case breaking game 2

Balance the reaction: Cus + HNO3 → Cu (NO3) 2 + S + NO + H2O

1. Give the elements that exist only on one of the compounds on the left and the right side.

CUS + HNO3 → Cu (NO3) 2 + S + NO + H2O

2. Start by giving the coefficients on compounds that have marked the element most numerous and most indexed. In this example, cus given a coefficient of 1.

1 Cus + HNO3 → Cu (NO3) 2 + S + NO + H2O

3. Balance the Cu atoms and S. In this case, Cu (NO3) 2 and S each got koefifen 1.

1 Cus + HNO3 → 1 Cu (NO3) 2 + 1 S + NO + H2O

4. At this point we were interrupted game. To continue this game we will give the coefficient on the variable form other compounds.

1 Cus + a HNO3 → 1 Cu (NO3) 2 + 1 S + b NO + ½ a H2O

H2O ½ a given coefficient for the number of H on the left is a.

a. By equating the number of atoms on the left and the right we will get the following relationship.

N: a = 2 + b

b = a - 2 .............................. .. (i)

O: 3a = 6 + b + ½ a

A = 6 + 2½ b ......................... (Ii)

b. Substituting (i) to the equation (ii).

A = 6 + 2½ (a - 2)

1½ a = 4

a = 8/3

c. Substitute a value equal to (i)

b = 8/3 - 2 = 2/3

5. The full reaction to be as follows.

1 8/3 CUS + HNO3 → 1 Cu (NO3) 2 + 1 S + 2/3 + 4/3 H2O NO

So that the coefficient of reaction does not contain fractions, the above reaction multiplied by three.

3 CUS + 8 HNO 3 → 3 Cu (NO3) 2 + 3 S + 2 NO + 4 H2O

Exercises

Balance the following reactions.

1 (NH4) 2Cr2O7 → Cr2O3 + N2 + H2O

2 Fe2S3 + H2O + O2 → Fe (OH) 3 + S

3 MnO2 + H2SO4 + NaI → MnSO4 + Na2SO4 + H2O + I2 (hint: consider SO4sebagai unity)

4 KMnO4 + H2SO4 + H2C2O4 → MnSO4 + K2SO4 + CO2 + H2O (hint: H2C2O4dapat written as H2 (CO2) 2)

5 K2Cr2O7 + FeSO4 + H2SO4 → CR2 (SO4) 3 + Fe2 (SO4) 3 + K2SO4 + H2O

6 KIO3 + KI + HNO3 → I2 + KNO3 + H2O

7 Al + KOH + As2O3 → KAlO2 + AsH3 + H2O

8 FeS + HNO3 → Fe (NO3) 3 + S + NO + H2O

9 As2O3 + KMnO4 + H2SO4 → H3AsO4 + MnSO4 + K2SO4 + H2O

10 CrI3 + H2O2 + KOH → K2CrO4 KIO4 + H2O +

    

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Mol concepts

Mol concepts

TOPICS: Concepts Mol

Mol concepts





If in our daily lives we know the unit number in the form of a dozen (12 pieces), scores (20 pieces), and the rim (500 pieces) then the chemistry we know the mole as the unit number. One mole is defined as the amount of a substance containing particles according to the number of atoms in 12 grams of carbon-12. Since the mass of one atom C-12 is 1.992 × 10-23 grams, then the number of atoms in one mole (12 grams) of C-12 can be calculated as follows:

                                              

the number of atoms

Numbers 6.02 x 1023 is called Avogadro's number and Latau denoted by NA. Thus, one mole of a substance is the amount of substance containing 6.02 x 1023 particles. If n states the number of moles and N denotes the number of atoms or molecules, then the relationship n and N can be written in the following formula.
                                               


Molar mass

The molar mass is the mass of one mole of a substance. The value of the molar mass of a substance is always the same with Ar or Mr substances. The relationship of mass and number of moles of a substance can be written in the form of the following formula.

gram-mole

Volume Molar Gas

Gas molar volume is the volume of 1 mol of gas. Due to the volume of gas is strongly influenced by temperature and pressure, the stoichiometry of the chemists define a reference condition in the determination of the molar volume. This reference condition is 0 ° C (273 K) and 1 atm. This condition is called standard conditions or STP (Standard Temperature and Pressure). At STP conditions, molar volume of gas is 22.4 L. Thus, the relationship number of moles of gas (n) with its volume can be written by the following equation.

volume-mol

Volume (V) and the molar volume (Vm) gas expressed in liters.

- See more at: http://apapikir.com/2016/02/12/konsep-mol/#sthash.AxJOz9xS.dpuf

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The relative atomic mass and molecular mass Relative

The relative atomic mass and molecular mass Relative

TOPICS: relative atomic mass and molecular mass Relative


The relative atomic mass and molecular mass Relative

Source: http: //www.mystupidtheory.com/



Atoms are very small particles. Because the atomic mass is also too small when expressed in units of grams so that the chemists created a way to measure the mass of an atom, namely the relative atomic mass. The relative atomic mass (Ar) is the ratio of the average mass of an atom with one-twelfth times the mass of one atom of carbon-12.

Ar

The smallest unit of a substance can also be a molecule. Molecules composed by two or more atoms held together by chemical bonds. Relative molecular mass (Mr) adalahperbandingan average mass of a molecule with one-twelfth times the mass of one atom of carbon-12.

Mr

In the above formulas used atomic mass and molecular mass on average. Why use an average atomic mass? Because the elements in nature have beberapaisotop. For example, the carbon in nature has two pieces of stable isotopes is C-12 (98.93%) and C-13 (1.07%). If the abundance and mass of each isotope is known, the relative atomic mass of an element can be calculated by the formula:

isotope
Given the relative atomic mass of each element making up the molecule, relative molecular mass equal to the amount of relative atomic masses of all the atoms making up the molecule. Molecules that have a formula in one molecule AmBn means there tersbut m n atom atom A and B. Thus AmBndapat relative molecular mass is calculated as follows.

Mr-AmBn

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10 Understanding And Personality Metal According Physicist

10 Understanding And Personality Metal According Physicist

TOPICS: 10 Definition and properties of metals According Physicist


10 Understanding And Personality Metal According Physicist


DosenPendidikan.Com - In chemistry, a metal or metal categorized by Greek = Metallon is a chemical element that is ready to form ion cations and has metallic bonds, and sometimes it is said that it is similar to the cation in a cloud of electrons. Metal is one of the three groups of elements that can be distinguished by ionization and bonding properties, along with the metalloids and non-metals.

Metal

Metal
In the periodic table, a diagonal line drawn from boron (B) to polonium (Po) distinguishes metals from non-metals. Elements on this line are metalloids, sometimes called semi-metal, the element on the lower left is a metal, an element to the upper right is non-metallic.

The non-metallic in nature there are more than metal, but there are a lot of metal in the periodic table. Some well-known metals are aluminum, copper, gold, iron, lead, silver, titanium, uranium, and zinc.

Allotropes of metals tend to be shiny, soft, and a good conductor, while non-metals are usually brittle (for solid nonmetals), not shiny, and insulators.

In the field of astronomy, the term metal is always used to mention all the elements that memepunyai properties of objects heavier than helium.

Metal properties

chemical properties

Metals normally tend to form cations by removing electrons, then react with oxygen in the air to form an oxide bases. For example:

4 Na + O2 → 2 Na2O (sodium oxide)
2 Ca + O2 → 2 CaO (calcium oxide)
4 Al + 3 O2 → 2 Al2O3 (aluminum oxide)
Transition metals such as iron, copper, zinc, and nickel, takes longer to oxidize. Others, such as palladium, platinum and gold, do not react with the air at all. Some metals such as aluminum, magnesium, several kinds of steel, and titanium has a "patron" at the very outside, so are not able to be penetrated by oxygen molecules.

The process of painting, anodizing or plating on metal is usually the best steps to prevent corrosion.

physical properties

Electrical conductivity, thermal conductivity, luster and density properties. Metal that has a density, and hardness, and a low melting point example: metals generally have a high rate in the alkali metals and alkaline earth metals, are usually highly reactive. A high number of free electrons in any form solid metal causing the metal never look transparent.

The majority of the metal has a higher density than non-metals. However, variations in the density of this difference is very large, ranging from metallic lithium as the density of the smallest to osmium metal in the greatest density.

alloy

Alloy is a blending of two or more types of metal to get the physical, mechanical, electrical and better visual. Examples of metal alloys are popular is stainless steel which is a blending of iron (Fe) and chromium (Cr).

Use of Metal

Generally, the metal can be useful for people, for use in the field of industry, agriculture, and medicine. Such as the use of mercury in chlor alkali process. Chlor alkali process is an electrolytic process that plays an important role in manufacturing and purification chemicals.

Some of the chemicals that can be obtained by the process of electrolysis is sodium, calcium, magnesium, aluminum, copper, zinc, silver, hydrogen, chlorine, fluorine, sodium hydroxide, potassium bichromate and potassium permanganat.Proses electrolysis of sodium chloride solution is a process klor- alkali.

NaCl electrolysis to produce sodium hydroxide in the cathode (positive pole) and chlorine gas at the anode (negative pole). In the aerospace industry and the medical profession needed a strong material, resistant to corrosion, and noniritin, such as titanium alloys.

Most types of metal is an important element because it is needed in a variety of biochemical functions. In ancient times, certain metals, such as copper, iron, and tin used to make tools, machine tools, and weapons.

Precious metal

In general, precious metals mean metals, including alloys commonly used as jewelry, such as gold, silver, copper and platinum. These metals have a nice color, rust resistant, soft and present in small quantities in nature. Gold and silver have properties very good conductor of electricity so it is widely used to coat the connectors on an electronic device.

Heavy metal

Heavy metal (heavy metal) is a metal with a density of five or more, with an atomic number of 22 to 92. These heavy metals in the appraiser can harm health if it accumulates excessively in the body. Some are raised cancer (carcinogens). as is the case with foodstuffs with high heavy metal content deemed unfit for consumption.

The cases of environmental pollution causes a lot of foodstuffs containing excessive heavy metals. Case is a popular Minamata syndrome, as a result of the accumulation of mercury (Hg) in fish consumption.

In Indonesia, once proclaimed that the fish in the Bay of Jakarta also has a high mercury content. Shrimp from ponds in Sidoarjo been denied importers from Japan as it is considered to contain cadmium (Cd) and lead (Pb) which exceeds the threshold.

Allegedly these metals is the effect of the disposal of industrial waste around their environment. Cocoa from Indonesia was also rejected at an international auction because it is considered to contain cadmium above the permitted threshold. Cd probably derived from TSP fertilizer given to plants in plantations.

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Types of Synthetic Sugar and health impacts

Types of Synthetic Sugar and health impacts

TOPICS: Types of Synthetic Sugar and health impacts

POSTED BY: NANDASANJAYA FEBRUARY 12, 2016

 

Types of Synthetic Sugar and health impacts

 

Source: http: //www.mystupidtheory.com/

 

How much sugar is consumed by humans every day? Many .. Very much. The demand for sugar are so many causes production of natural sugars, sucrose is not enough. Industry must eventually produce several types of synthetic sugar to meet the needs of the market.

To produce natural sugars, sucrose, it takes a very long time in the production of raw materials such as sugar cane. Therefore the use of artificial sweeteners is necessary to meet the demands of our daily sugar.

1. sucralose, or Splenda

Types of Synthetic Sugar and health impacts

Nonkalori sweetener sucralose is a synthetic (artificial) with the code E955. The most famous being sucralose Splenda brand. This product received permission from U.S. Foode and Drug Administration, the Joint Food and Agriculture Organization / World Health Organization Expert Committee on Food Additives and The Canadian, and European Australiann Regulating Bodies.

This quickly popular sweetener in the food industry because it has a strong sweet taste, and a high stability when heated. So it is suitable for use in the bakery industry. The level of sweetness of sucralose up to 1000 times that of sucrose.

Permission to circulate for sucralose given 20 years ago, with a statement from the FDA that sucralose is not carcinogenic, reproductive and neurological problems. But lately studit shown that Sukarlosa have side effects.

Sukarlosa predicted to be the cause of migraine (headaches), gastrointestinal problems and Thymus. So for people with migrant or head problems, it is recommended to avoid sucralose.

2. Aspartame

Types of Synthetic Sugar and health impacts

Aspartame is a sweetener without calories synthetic (artificial). In the science kimiaAspartam known as methyl ester of a dipeptide form.

Aspartame is declared fit for use as additives in food since 1981 by the FDA. Various studies have been conducted to evaluate this decision.

For more than 19 years has been done 26 times evaluation of the dangers of Aspartame, but the FDA does not change its decision and allow aspartame to be used globally in the industry.

Based on some recent research, it is known that the amount of aspartame that may be consumed by the body is 40mg / kg body weight. Other studies reveal that there is a relationship between the consumption of aspartame with cancer gejalan. Then Aspartame is the greeting of the food additives that should be avoided.

3. Saccharin

Types of Synthetic Sugar and health impacts

Saccharin is a sweetener without calories synthetic (artificial) which allowed its use in general for industrial products. Saccharin is currently used as a sweetener in foods and beverages without the calories.

Saccharin was initially suspected of being carcinogenic compounds cause cancer, but in 2000 another evaluation done on the use of saccharin and decided by the EPA that saccharin is safe to use.

Saccharin has 300 times the sweetness of sucrose or sugar. But limits the use of saccharin is only for the industry, rather than direct home consumption.

In 1970, saccharin is believed to be a cause of cancer. Several recent studies have assigned the result that saccharin impact bladder cancer in experimental mice subject. But until now no bladder cancer in humans, so there is no evidence that saccharin is a cancer-causing chemicals. Various studies that have been done are not able to prove this point.

Therefore, it can be concluded that saccharin is the most secure type Sintetisyang sugar for consumption.

Source reads:

https://id.wikipedia.org/wiki/Sukralosa

https://id.wikipedia.org/wiki/Aspartam

https://id.wikipedia.org/wiki/Sakarin

http://www.livestrong.com/article/85719-dangers-sucralose/

http://www.livestrong.com/article/465273-which-is-worse-saccharin-or-aspartame/

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