Gita.Shine

THE LAW OF CONSERVATION OF MASS (LAVOISER LAW)                Have you ever considered a piece of iron left in the open air, and at one time we will find, whether the iron has been turned into rust iron? If we weigh the mass of iron before rusting with the rust of iron produced, it turns the mass of iron rust is greater. Is that right? You often see wood or paper on fire, do not you? Results obtained. If you weigh the ash then the ash mass is lighter than the mass of wood or paper before it is burned. Is that right? From the event, we feel it as a chemical reaction, there is a difference in the mass of matter, before and after the reaction.                  Antoine Laurent Lavoisier (1743-1794) a French chemist has obtained a mass relationship of substances before and after the reaction. Lavoisier weighed the substances before...

Why Rubber Can Grow?      If there is a statement will make us really fascinated to the molecules, maybe the following, rubbery or stretchy because it consists of molecular-molecule stretch. Rubber bands, for example, can be elongated because each molecule itself has a wake up like a mini rubber band.      Rubber molecules have a long, thin form of worms that lazy like to take a coiled position but can be straightened when pulled right on the heads and tails. A piece of rubber on its hiccup like a can of worms that are all tangled up to a tangle.      But imagine we can straighten a can of worms by pulling our heads and tail randomly, all going to hold each other in different directions. Two worms must be intertwined in such a way that the pull on one will be extended to others and so on. All we need is a can of worms tied to each other along their bodies. Such is the arrangement of rubber molecules. However, the arrangement is...

A. Basic Competencies and Indicators Basic competencies Indicator 3.6 Determining the shape of molecules by using the theory of electron valence shunt pair (VSEPR) or Electron Domain Theory 1. Explain the theory of electron domains 2. Applying the theory of electron domains in determining the shape of molecules 3. Explain the theory of electron valence skin pair rejection (VSEPR) 4. Determining the form of molecules based on the theory of repulsion of the valence skin pair of electrons (VSEPR) 5. Determining the nature of polarity based on molecular form 4.6   Make a model of molecular shape by using materials in the environment or chemical software 1. Applying the electron domain theory to predict the shape of the molecule 2. Make a molecular shape by using a balloon 3. Communicate the results of discussions about the molecular form. B. LEARNING MATERIALS 1. Electron Domain Theory 2. Theo...

Rendement is actually a term in the field of chemistry studies. Rendement image of the reaction results inaccuracy, where the result is always lower than the mathematical calculation. For example, in a chemical reaction, it should produce a weight of 100 grams, mathematically, but at a yield of only 90 grams. Unconsciously this also often happens in our daily lives.             In chemistry, the chemical yield, the yield of the reaction, or only the rendement refers to the amount of reaction product produced in the chemical reaction. Absolute rendement can be written as weight in grams or in moles (molar yield). The relative yield used as a calculation of the effectiveness of the procedure is calculated by dividing the amount of product obtained in moles by the theoretical yield in moles To obtain a percentage yield, multiply the fractional yield by 100%. One or more reactants in chemical reactions are often used redundantly....

I.        Title : THERMOCHEMICAL AND HESS LAWS II.     Purpose:             1.       Measuring caloric reaction with simple tool.       2.       Collecting and analyzing thermochemical data.       3.        Apply the Hess law. III. Practice Questions:     1.       Provide an understanding of: (a) enthalpy; (B) isolated systems; (C) open system; (D) closed system; (E) the environment; (F) calorimeter; (G) exothermic. Answer: A.     Enthalpy is the sum of the energy of all forms of energy possessed by the substance whose quantities can be measured. B.      An isolated system is a system that can not drain energy and material to its surroundings. C.      Open system is a system that allows the flow or ex...