USING ENGLISH SHOW CAUSE AND EFFECT

Cause and effect when chemical reactions occur

Chemical reactions are a natural process that always results in the conversion of chemical compounds. [1] The compounds or the initial compounds involved in the reaction are referred to as reactants. Chemical reactions are usually characterized by chemical changes, and will result in one or more products that typically have different characteristics of the reactants. Classically, a chemical reaction involves a change involving the movement of electrons in the formation and disconnection of chemical bonds, although essentially the general concept of chemical reactions can also be applied to the transformation of elementary particles such as nuclear reactions.
Chemical reactions are chemical change events of substances that react (reactants) to reaction products (products). In the chemical reaction always produced new substances with new properties. Chemical reactions are written using elemental symbols.

A.    The characteristics of chemical reactions

 When chemical reactions occur, there are changes we can observe. Note the following chemical reaction characteristics.

a. Chemical Reactions May Cause Color Changes: For example we can observe that the purple color in potassium permanganate solution (KMnO4) will change if reacted with oxalic acid solution (H2C2 O4) This chemical change occurs because the potassium permanganate compound turns into a colorless manganese sulphate (MnSO4) compound. Likewise, the green copper carbonate (CuCO3) will turn into a black-colored copper oxide (Cu2O) and carbon dioxide (CO2) after heating.

b. Chemical Reactions Can Form Sludges  When barium chloride (BaCl2) is reacted with sodium sulfate (Na2SO4) it will produce a barium sulphate white precipitate (BaSO4). This white precipitate formed is difficult to dissolve in water. The chemical reactions can be written as follows.    

       BaCl2 + Na2SO4 → BaSO4 + 2NaCl        

  (Solution) (solution) (solids) (solution) Lots of chemicals reacted to precipitate. Another example is the silver nitrate solution (AgNO3) reacted with sodium chloride solution (NaCl) resulting in a silver white chloride (AgCl) and sodium nitrate (NaNO3) solution.              AgNO3 + NaCl → AgCl + NaNO3    

(Solution) (solution) (solids) (solution)

Actually what is sediment? The precipitate is a substance that separates itself as a solid phase of the solution. The precipitate may be crystalline or colloidal and may Removed from the solution by filtration or centrifugation. The precipitate is formed when the solution becomes too saturated with the solute. The solubility of a precipitate is the same  With the molar concentration of the saturated solution. The solubility solubility increases with increasing temperature, although in some special cases (such as potassium sulfate), Going the other way around. The rate of increase in solubility with different temperatures. In some cases, changes in solubility with changing temperature may be the reason for separation.  For example the separation of lead ions from silver and mercury (I) can be achieved by depositing the three ions initially as chlorides, continued by adding hot water to the mixture. Hot water will dissolve lead chloride (PbCl2) but silver and mercury (I) chloride (HgCl) does not dissolve in it. After filtering the hot solution, lead ions will be found in the filtrate.

c. Chemical Reactions May Cause Temperature Changes  You can prove that chemical reactions can cause temperature changes. In the experiments reacting sulfuric acid (H2SO4) and sodium hydroxide (NaOH) there was an increase in temperature. Well, a chemical reaction that produces a temperature rise is called an exothermic reaction. Exothermic reactions can be found in paper burning and gasoline combustion in motor vehicles. In the second experiment, when you react the mixture of barium hydroxide (Ba (OH) 2) and ammonium chloride (NH4Cl) , The solution will absorb the heat around it resulting in a decrease in temperature. The chemical reaction that absorbs heat around it is called the endothermic reaction. Examples of endothermic reactions in everyday life are photosynthesis and food cooking.

            d. Chemical Reactions Cause Gas

             Have you ever dissolved high calcium vitamin tablets (effervescent tablets) into a glass of water? When you dissolve high calcium vitamin tablets into a glass of water, you will see bubbles of gas emerging from the solution. This proves that in the event of a chemical reaction can cause gas. In addition to the above example, you can also observe chemical reactions Which produces gas when you open carbonated drink cans.

B. Types of chemical reactions

            1. Burning reaction

               Combustion reaction is a type of chemical reaction in which a compound together with oxygen react with each other so that the formation of new compounds consisting of oxygen.

               The main characteristic of this reaction is that the role of oxygen is quite large, as has been known the availability of oxygen is an absolute requirement of a propane combustion reaction that produces a new substance of carbon dioxide

                    CO2 + H2OàReaction Example: C3H8 + O2

2. Reaction of merging

  The merging reaction is a type of chemical reaction that occurs formation of a new substance comprising the substances forming the substance. The coalescing reaction is also called the forming reaction. The main concept of the reaction is that the new substance that is formed must come from the reaction between the substances.

Reaction Example:

  Example of the above reaction is the reaction of water formation from the formation of its constituents, namely Hydrogen and Oxygen. In the initial state and room temperature, the forming agents can not be encountered in the form of monoatomic elements (elements formed only from one atom). Under normal circumstances,Elements like hydrogen and oxygen consist of two atoms called diatomic elements.

3. Decomposition reaction

The decomposition reaction is a chemical reaction that occurs where larger and more complex substances are decomposed into their sulfur substances. When noticed, this type of chemical reaction is the opposite of a merging or forming reaction. For more details see the following example of the reaction. HCl As well as in the reaction of the formation of substances formed from the decomposition reaction must also be formed into substances that are stable from its forming elements. In the example of the above decomposition reaction, the HCl substance is described to be the forming agents comprising hydrogen gas and chlorine gas. The hydrogen gas must be a diatomic compound while the chlorine gas is also formed from the binding of two Cl (unsat diatomic) atoms as elements of the halide group (VII A).

4. Metathetic Reactions

Metathetic reaction is the exchange reaction of two ectolite-forming ions of certain salts. The reaction may occur when one of the reactants or the desired reaction product has a low moisture in the water (solvent). In other words, this reaction can occur when the sludge precipitates as the final product of the reaction. Reaction Example:

NaCl + AgNO3 ¬ -> AgCl + NaNO3

The two reagents (on the left side of the arrow) are a salt electrolyte solution. Both salts are then mixed so that there is a reaction in it. In the form of exchanges he is positive and negative of each reactor. As mentioned above, this reaction can happen what if the expected reaction results have a low solubility.

causes and effect of acid rain

      Naturally the process of acid rain is caused by volcanoes and from the process of bio-chemical processes that occur in swamp, sea and soil.But basically the occurrence of acid rain occurs due to human activities themselves such as from the field of industry, power plants, emulsions, etc .  All the gas produced by human activity will be carried by the wind until it reaches the earth's atmostfer so it drops with rain and then settles on the ground.

Simply forming the acid is through a chemical process, with the reaction as follows:  

              

 Evidence of the impact of acid rain is evident, since the Indrustri Revolution in Europe, there was a dramatic decrease in pH at the north pole, the pH at the north pole that was 6, has now fallen to 4.5. Not only are changes in pH alone, but there is also a small organism called diatoms, the diatoms are settled in the ponds, for years, then the diatoms die and settle on certain sediments at the bottom of the pond. The amount of diatoms that settle at the bottom of the pool can be a clue to the pH level, because the high pH affects the growth of the diatoms. So with the data can be known difference in pH at the north pole due to acid rain from year to year.

Acid rain was first discovered in Manchester in 1852 by Robert Angus Smith. The new scientists conducted research on acid rain in the 1970s. Concern for the new acid rain took place in 1990 when the New York Times published the Hubbard Brook Experimental Forest report in New Hampshire about acid rain causing much damage to the environment.

 The impact of acid rain Inhibiting the breeding of animals that live in the water will die, the smaller pH will inhibit the growth of fish larvae, making fish difficult to breed, such as trout.

Destroying various types of fish, according to research, plankton can not survive when the pH in the water below 5, while the plankton is the basic food of the fish and the situation can lead to food chain breaking, too small pH will also make some metals will mix like aluminum , The condition can cause the fish to remove a lot of mucus from its unconscious so that fish will be difficult to express.

Toxic to humans, acid rain can also affect human health. Acid rain will spread to rivers, lakes and waterfalls, too low pH is not good for humans.

 Environmental damage, acid rain can cause plants to die. Acid rain will destroy the wax substances contained in plants. Nutrition existing in the plant will be lost, so the plant can easily attack seprti fungus disease. The destruction of the forests that are affected is in the mountains, because in those areas there is frequent rainfall.