Chemical reaction
One of the material changes is chemical change or better known as chemical reaction. In everyday life, many events are chemical reactions.
When someone burns trash, he has caused a chemical reaction. When the garbage is burned it will cause a hot fire and smoke.
Another example of chemical reactions is the decaying of rice that has been left on for several days. If the rice rot, then the color changes, which was white to white gray.
The chemical reactions that occur have certain characteristics. Therefore, to recognize the occurrence of a chemical reaction can be seen from the characteristics generated during the chemical reaction takes place.
How to write a chemical reaction? What are the characteristics of a chemical reaction? What factors affect the occurrence of a chemical reaction?
In this discussion, you will learn how to write down chemical reactions, the characteristics of the occurrence of a chemical reaction and the factors that affect the rate of chemical reactions.
How to Write Chemical Reactions
Chemical reactions always produce new substances. Therefore, the word "react" means "forming a substance".
The reacting substances are called reactants (reactants), while the newly produced substance is called the reaction product (product). The chemical reaction is written with arrows to indicate the direction of change or the direction of the reaction.
The notation of a chemical reaction is as follows:
Example:
Reactants are substances that react. The product is a substance produced from a chemical reaction.
Carbon and oxygen react to produce carbon dioxide. Notations of chemical reactions are:
Characteristics of Chemical Reactions
What are the characteristics of chemical reactions? Here are the characteristics.
The characteristics of chemical reactions
Chart: Characteristics of chemical reactions
One of the material changes is chemical change or better known as chemical reaction. In everyday life, many events are chemical reactions.
When someone burns trash, he has caused a chemical reaction. When the garbage is burned it will cause a hot fire and smoke.
Another example of chemical reactions is the decaying of rice that has been left on for several days. If the rice rot, then the color changes, which was white to white gray.
The chemical reactions that occur have certain characteristics. Therefore, to recognize the occurrence of a chemical reaction can be seen from the characteristics generated during the chemical reaction takes place.
How to write a chemical reaction? What are the characteristics of a chemical reaction? What factors affect the occurrence of a chemical reaction?
In this discussion, you will learn how to write down chemical reactions, the characteristics of the occurrence of a chemical reaction and the factors that affect the rate of chemical reactions.
How to Write Chemical Reactions
Chemical reactions always produce new substances. Therefore, the word "react" means "forming a substance".
The reacting substances are called reactants (reactants), while the newly produced substance is called the reaction product (product). The chemical reaction is written with arrows to indicate the direction of change or the direction of the reaction.
The notation of a chemical reaction is as follows:
Example:
Reactants are substances that react. The product is a substance produced from a chemical reaction.
Carbon and oxygen react to produce carbon dioxide. Notations of chemical reactions are:
Characteristics of Chemical Reactions
What are the characteristics of chemical reactions? Here are the characteristics.
The characteristics of chemical reactions
Chart: Characteristics of chemical reactions
1. Making Gas
Chemical reactions can cause gas during the reaction. Gases produced by chemical reactions may be oxygen gas, carbon dioxide gas or hydrogen gas.
Examples of chemical reactions that produce gases are wood burning reactions, photosynthetic reactions, and carbonate salt reactions with acidic solutions.
An example of a chemical reaction that produces carbon dioxide (CO2) gas is the reaction of a carbonate compound with an acid solution. The chemical reaction equation is as follows:
Carbonate + hydrochloric acid → chloride salt + water + CO2 gas
Carbonate + sulfuric acid → sulfuric salt + water + CO2 gas
An example of a chemical reaction that produces hydrogen gas is a metal reaction with hydrochloric acid. The chemical equation is as follows:
Metal + hydrochloric acid → chloride salt + hydrogen gas
2. Temperature Changes occur
Chemical reactions are absorbing heat and some are releasing heat. The absorption or release of heat by a chemical reaction can cause temperature changes in the environment around the site of the reaction.
If the chemical reaction absorbs heat, then the temperature in the surrounding environment will decrease (become colder). A chemical reaction that absorbs heat is called an endothermic reaction.
Conversely, if the chemical reaction releases heat, then the temperature in the surrounding environment will increase (hotter). A chemical reaction that releases heat is called an exothermic reaction.
If the urea fertilizer (NH3) is introduced into water, then the water temperature will decrease (cooler). This is due to the reaction of urea fertilizers with water including heat-absorbing chemical reactions (endothermic reactions).
3. Color Changes occur
A chemical reaction can cause color changes in reacting substances. An example of a chemical reaction that causes discoloration of the reacting agent is the reaction between the FeCl3 (brown) solution and the KSCN (colorless) solution.
If the FeCl3 solution is dropped into KSCN solution, a color change in the KSCN solution will occur. The chemical reaction equation is as follows.
Solution FeCl 3 + KSCN solution → Fe (SCN) 2+ + KCl solution
4. Embossed Sludge
A chemical reaction can produce precipitate. The formation of precipitate in a chemical reaction is based on the fact that not all matter is soluble in water. If the reaction material is not soluble in water, then the reaction proceeds to settle.
Some of the water insoluble compounds are AgCl, CaCl2, AgBr, carbonate salts (CaCO3, BaCO3), phosphate salts or Ca3 (PO4) 2, and sulfide compounds (H2S, FeS, MgS).
If the sodium hydroxide solution (NaOH) is reacted with hydrochloric acid (HCl) solution, it will form sodium chloride (NaCl) and water.
The reaction material is sodium chloride and water. Both materials are soluble in water so that the chemical reaction does not produce precipitate.
If the sodium chloride (NaCl) solution is reacted with AgNO3 solution, an AgCl and NaNO3 solution will be formed. NaNO3 solution is soluble in water, but AgCl is not soluble in water
EXAMPLE OF CAUSE AND EFFECT OF CHEMICAL REACTION
Corrosion
cause of corrosion
Corrosion can occur because of the reaction between metal and surrounding substances. In rust, this rust can occur due to moist air (oxygen and water) to corrode (react) to the iron so that a new substance appears reddish brown solids.
For corrosion event itself is an electrochemical process that is process (change / chemical reaction) that involves the existence of electric current. Certain sections of iron act as negative poles (anode negative electrode) while the other part as a positive pole (cathode positive electrode). Electrons flow from the anode to the cathode so that corrosion events occur.
Corrosion can occur because of the reaction between metal and surrounding substances. In rust, this rust can occur due to moist air (oxygen and water) to corrode (react) to the iron so that a new substance appears reddish brown solids.
For corrosion event itself is an electrochemical process that is process (change / chemical reaction) that involves the existence of electric current. Certain sections of iron act as negative poles (anode negative electrode) while the other part as a positive pole (cathode positive electrode). Electrons flow from the anode to the cathode so that corrosion events occur.
EFFECT OF CORROSION
IN LIFE
In everyday life, corrosion can be encountered in various metals. Buildings and electronic equipment that use metal components such as zinc, copper, iron-steel and so on can all be attacked by this corrosion. Zinc for the roof can leak due to corrosion. Likewise the iron for the fence can not be free from corrosion problems. Bridges of steel and car bodies can become brittle due to a natural event called corrosion. This is because the corrosion that attacks the devices and electronic components can involve damage and even accidents. Because of this corrosion, the electrical properties of electronic components in computers, televisions, video, calculators, digital clocks and so on in the life of the household become corrupted.
Corrosion is a serious technical and scientific problem. In developed countries though, this problem has not been solved scientifically answered until now. Besides being a matter of surface science which is a study and needs to be handled physically, corrosion also concerns the reaction kinetics which becomes the study area of the chemists.
Corrosion is also an economic problem because it involves the age, depreciation and efficiency of the use of a material or equipment in industrial activities. Billions of US Dollars have been spent annually to maintain bridges, office equipment, motor vehicles, industrial machinery and other electronic equipment so that the lifetime of construction can last longer.
Many countries have attempted to calculate the cost of national corrosion in different ways, generally falling on values ranging from 1.5 to 5.0 percent of GNP (Gross National Product). Practitioners today tend to agree to set corrosion costs about 3.5 percent of GNP. Losses that can be caused by corrosion are not only direct costs such as industry equipment change, bridge maintenance, construction and so on, but also indirect costs such as disruption of production processes in the industry and the smoothness of transportation which is generally larger than direct costs. Of all the losses incurred it is deemed necessary so that we can know what steps can prevent or suppress the rate of corrosion.
In everyday life, corrosion can be encountered in various metals. Buildings and electronic equipment that use metal components such as zinc, copper, iron-steel and so on can all be attacked by this corrosion. Zinc for the roof can leak due to corrosion. Likewise the iron for the fence can not be free from corrosion problems. Bridges of steel and car bodies can become brittle due to a natural event called corrosion. This is because the corrosion that attacks the devices and electronic components can involve damage and even accidents. Because of this corrosion, the electrical properties of electronic components in computers, televisions, video, calculators, digital clocks and so on in the life of the household become corrupted.
Corrosion is a serious technical and scientific problem. In developed countries though, this problem has not been solved scientifically answered until now. Besides being a matter of surface science which is a study and needs to be handled physically, corrosion also concerns the reaction kinetics which becomes the study area of the chemists.
Corrosion is also an economic problem because it involves the age, depreciation and efficiency of the use of a material or equipment in industrial activities. Billions of US Dollars have been spent annually to maintain bridges, office equipment, motor vehicles, industrial machinery and other electronic equipment so that the lifetime of construction can last longer.
Many countries have attempted to calculate the cost of national corrosion in different ways, generally falling on values ranging from 1.5 to 5.0 percent of GNP (Gross National Product). Practitioners today tend to agree to set corrosion costs about 3.5 percent of GNP. Losses that can be caused by corrosion are not only direct costs such as industry equipment change, bridge maintenance, construction and so on, but also indirect costs such as disruption of production processes in the industry and the smoothness of transportation which is generally larger than direct costs. Of all the losses incurred it is deemed necessary so that we can know what steps can prevent or suppress the rate of corrosion.
How a substance can change color
BalasHapusWhen a substance undergoes a color change there must be an example
HapusApples that are cut and left for a while, over time will be
Changed to brown. This color change indicates the chemicals in apples have undergone with oxygen in the air. The reaction between the starch starch solution with iodine tintur can be known from the color change that occurs. Clear starchy kanji solution, brown iodine. If there is mixed will form a blue color. If added vitamin C then iodine will be given vitamin C with other chemicals that are colorless. Similarly, the chemical reaction can be known from the color changes that occur
What are the long-term and short-term effects of a chemical reaction?
BalasHapusOther somatic effects are seen in the body's physical abnormalities, such as:
HapusO Acute and chronic dermatitis (skin damage).
O Conjunctivity and keratitis in the eyes. The eye lens has excessively sensitive radiation resulting in cataracts. (Radiation 400 - 500 rad cause).
O Doses of 600 rads affect sterilization in generative devices (genitalia) and at low doses cause gene mutations as well as abnormalities in offspring. Reduces fertility of sperm and ovum and can cause anomalies (other genetic disorders).
O Coughing, shortness of breath, and chest pain and pulmonary fibrosis.
O Inflicts bone growth and osteoporosis.
O Increases myelitis (neurological disorders) and decreases degeneration of the brain and tissues.
O Fever, weakness, lack of appetite, nausea (nausea), headache and diarrhea.
O Increases the genetic effect at doses 25 - 150 brakes.
What are the positive and negative effects that will occur if consuming water refills in the long run
BalasHapusExcess water refill:
Hapus1. The price is relatively cheap as the price of AMDK.
2. Easy to get
3. Although not all but the quality of water refills already meet the standards of the Ministry of Health. This will depend on the quality of sanitation, machinery and raw materials of water.
Disadvantages of water refills:
1. Weak supervision and supervision makes water quality inconsistent.
2. The possibility of misplaced production is relatively high, especially concerning the selection of raw water, equipment selection and sanitation.
3. The rules regarding the services of refill depots are not clear. This concerns the quality of production so that the protection of the law specifically on the consumer if there is no case.
4. The process for packaging only rely on simple technology so that often occur contamination by bacteria.
Danger of drinking water refills
1. Location of Filling Depot located on the edge of the Highway
One of the things that can endanger refill drinking water for its consumers because of the location of the depot that is on the edge of the highway. It is common knowledge, if the highway is a source of pollution and dust. Various viruses and other bacteria can interfere with the health of the body, can even be the cause of the most deadly disease.
The condition of the depot that is not sterile is of course less healthy. Places adjacent to the highway will make a lot of bacteria enter and attach to the equipment used by the owner of the drinking water depot.
2. Non-Standard Galile Cleanup Process
When going to refill drinking water process, consumers usually do not know how the owner of drinking water refill depot is cleaning gallons. The brushes commonly used for cleaning gallons are outdoors and alternated with others.
How can it make gallons and steriles from harmful germs and bacteria? This will actually make germs and bacteria attached to gallons of drinking water.
3. Non-sterile Water Filling Equipment
Water filling equipment, such as water supply pipes, filling faucets, and water storage tanks, have you ever seen the hygiene conditions? It must be rare for consumers to see that. And it can not be known how the cleanliness of the equipment.
The hazard of this refill drinking water is found in any bacteria that will enter the body through drinking water, which comes from the refill depot.
4. Unclear Drinking Water Supply Origin
When we talk about branded mineral water, it is possible to see the water source used by the water company. But when the water comes from the refill drinking water depots, do you know where the drinking water supply comes from?
Is the water completely pure and ready to be consumed, or is it still raw and contains many living bacteria, and is ready to terrorize your family?
Danger of Disease from Drinking Water
Of the four indicators, you might think twice about buying refillable drinks at a roadside depot. These four indicators will create harmful bacteria, such as e.colii and sallmonela. Here are some diseases that may be experienced when buying refill drinking water at an unofficial depot:
1. Stomach ache
2. Dysentery
3. Dizziness
4. Typhus symptoms
5. Symptoms of Chronic Illness, such as Hepatitis that can be delivered through the liquid
How does the oxidation reaction occur?
BalasHapus1. The binding and release of the oxygen element
HapusThe oxidation reaction (oxygenation) is the event of combining a substance with oxygen.
Example:
Si + O2 → SiO2
4 Fe + 3 O2 → 2 Fe2O3
The oxidation reaction of the metal is also known as the name of the carnation. Combustion reactions also include oxidation reactions, such as petroleum burning, paper, firewood, etc.
The reduction reaction is an oxygen discharge event of a substance.
Example:
2 CuO → 2 Cu + O2
H2O → H2 + O2
2. Electron release and binding reaction
The oxidation and reduction reactions can also be distinguished from the release and capture of electrons.
Oxidation is an electron release event
Example:
Na → Na + + e
Zn → Zn + 2 + 2e
Al → Al + 3 + 3e
Reduction is an electron capture event
Example:
Na + + e → Na
Fe +3 + e → Fe +2
From this second concept it can be concluded that oxidation and reduction reactions involve not only the reaction of a substance with oxygen.
3. Reaction of addition and reduction of oxidation number
Oxidation is the rise / increase of the oxidation number of an element, while reduction is the event of decreasing / decreasing the oxidation number.
What causes decay in rice?
BalasHapusDecomposition process on rice All organic ingredients including rice can be decomposed, this is caused by bacterial decomposers that carry out their activities, but rice or other organic matter will not decompose if released from decomposing bacteria, and there is no cause for the decline Water content. Chemical process that occurs, namely the process of release of N into free air. Of the decomposition results.Bacteria on the decay of rice Stale rice in the consequences of excess water causing the presence of bacterial decay, is guaranteed to feel at home nest because the water vapor through the steam outlet actually contains nutrients from the rice that evaporates due to heat. ap water rich in nutrients like this is very preferred bacteria so that other microbes are there ..! Result, rice enderung quickly stale because of contaminated bacteria from this part.An accidental rice goes here also become a medium to breed the bacteria, and the growth of mold On the rice that causes the growth of yeast as well.
HapusWhy if we wash using soapy water that we use is hard to foam?
BalasHapusThe hardness comes from the word sadah which means it contains lime, so if the water hardness is the presence of excessive lime content in water caused by the lime layer layers it passes. Types of water sources that contain many containers of ground water, especially deep ground water. Hard water can cause foamy soap, this is due to the sodium stearate (C17H35COONa) content in soaps that act with Mg2 + and Ca2 + ions that propel foam bubbles that precipitate,
HapusMg2 + (aq) + 2 C17H35COO- (aq) Mg (C17H35COO) 2 (aq)
Ca2 + (aq) + 2 C17H35COO- (aq) Ca (C17H35COO) 2 (aq)
Because soap is precipitated, a new soap foam will form when all magnesium and calcium ions have been deposited. This means to wash the required amount of soap. This kind of water causes:
1. The soap is difficult to foam, so the consumption of soap is higher for the purposes of bathing or washing,
2. Uncomfortable to drink (swallowed feels rough in the throat),
3. The formation of crust on the katel (pan) at the time the water is cooked, consequently the equipment becomes thicker and the use of energy for heating water becomes more.
4. In industries that use pipes to supply water, water can cause clogging of pipelines.
5. Contaminated water containing calcium (Ca) ions if consumed with oxalic acid which is widely found in spinach or pineapple vegetables will be able to form compounds of Ca-oxalate complex that settles on the urinary tract or called kidney stones.
Water hardness is caused by magnesium and calcium ions. Hardness is not beneficial because it lowers the surface tension of the water. Water considered to be of high quality has a low hardness. Calcium or magnesium can react in soap water with soap so the soap does not foam.