Using english to show cause and effect

Show cause and effect

For it is a matter expressed in order to establish a factual opinion which then actually occurs
Something which is the end or result of an event (deed, decision); Requirements or circumstances preceding it

Chemical change is a change that produces new substances. New substances produced there are those who can return to their original form and some are not able.

• Causes of chemical reactions:

1. Occurs due to burning.

2. Occurs due to mixing of substances.

3. Occurs due to the flow of electricity.

The chemical reaction equation is written as follows:

A and B reactants

C and D reaction products.

In the reaction equation there is a symbol of the form of substance: s (solid), aq (aqueous), l (liquid) and g (gas).

• Characteristics of chemical reactions:

A. Making gas

B. Formation of precipitate

C. Discoloration

D. Temperature changes

• Various kinds of chemical reactions:

1. Decomposition

2. Oxidation

3. Reduction

4. Neutralization

5. Precipitation

6. Exchange

7. Fermentation

• How to control the speed of the reaction can be done by changing:

A. Reaction temperature

B. Concentrations of reagents

C. Touch surface area

D. Catalyst

C. Chemical Reactions in Everyday Life

1. Corrosion

2. Decomposition of food

3. Fireworks

• Division of Material Nature

Based on the ability of substance

1. Physical properties: properties that can be observed without changing the identity of the substance.

Example: melting point, boiling point, heat conductivity, electric conductivity, density, hardness level etc.

2. Chemical properties: properties related to the ability of the substance to react to form other substances.

Example: the ability of a substance to react with oxygen, water, acid etc.

 Decay

       If food and drink are left too long, after a certain period of time the food and beverages will decay which is usually characterized by a change in appearance, such as discoloration and the appearance of a foul odor. The emergence of discoloration and foul smell indicates that there are new substances that were not present in the food and drink. Thus, decay is one example of chemical change

Unprocessed foods will worsen, when stored and consequently ingested. Butter, cheese, bacon, dried fruits and some traditional food products are derived from various processing processes to make excessive use of food. Regardless of the conversion from food examination to a more permanent form, however, a large amount of food is still losing every year as a consequence Of various types of food rot. It has been estimated that between 10 and 20 percent more food has been fully available if the mushrooms can be completely prevented.

Drying, decomposition, contamination with dirt from chemicals and damage by animals or insect pests occur when they all become part of food rot. In many cases, this short decay can be avoided if care is taken in transporting and storing food. The occurrence of unwanted chemical reactions, such as oxidation, also causes decay. The most important cause of food decay, however, is the attack of micro-organisms with or Such as yeasts and bacteria.

CORROSION

In general, corrosion is the destruction of metal objects due to environmental influences. The corrosion process can be explained electrochemically, for example in the process of ironing which forms iron oxide (F2O3.nH2O). Electrochemically, the process of ironing is an iron oxidation event of iron by oxygen from the air.

A. CORROSION OF DEFINITION

 Corrosion in iron due to conta with water. In the iron there is anode and there is a cathode.

Anode: Fe (s) → Fe2 + (aq) + 2e- Eo = +0,44 V

Codes: O2 (g) + 2H2O (l) + 4e- → 4OH- (aq) Eo = +0.40

---------------------------------- +

Cell reaction: 2Fe (s) + O2 (g) + 2H2O (l) → 2Fe2 + (aq) + 4OH- (aq) Eo = +0.84 V

The Fe2 + ion then undergoes further oxidation by reaction:

4Fe2 + (aq) + O2 (g) + (4 + 2n) H2O (l) → 2Fe2O3.nH2O + 8H + (aq)

Based on the potential value of the reaction, iron is an easily corrosive metal. Other metals with electrode potential values ​​greater than 0.4 V will be difficult to corrosive, since they will produce Eoreact <0 (negative) when in contact with oxygen in the air. The metals of silver, platinum, and gold have electrode potentials greater than 0.4 V so it is difficult to experience corrosion.

B. CORROSION / CORROSTING CAUSE FACTORS

1. Water and air humidity Judging from the reaction that occurs in the corrosion process, water is one important factor for the ongoing corrosion. Humid air that contains moisture will accelerate the process of corrosion.

2. Electrolyte Electrolyte (acid or salt) is a good medium for the transfer of charge. This results in the electrons being more easily attached to the oxygen in the air. Rain water contains acid, while salt water contains salt. Therefore rainwater and seawater are the main causes of corrosion. 3. Uneven metal surfaces Uneven metal surfaces facilitate the occurrence of poles of charge, which will eventually act as anode and cathode. Smooth and clean metal surfaces will cause difficult corrosion, because the poles that will act as anode and cathode are difficult to form.

4. The formation of electrochemical cells If two different metals are potentially tangent to the aqueous or moist environment, electrochemical cells may form directly. The lower potential metal will immediately release the electrons when in contact with a higher potential metal and will be oxidized by oxygen (O2) from the air. This results in faster corrosion occurring in potentially low metals, while potentially high metals are even more durable. For example, a rivet made of copper to connect iron would cause the iron around the rivet to rust more quickly.

 

C. HOW TO PREVENT CORROSIONS Corrosion events are difficult to prevent, but can be inhibited in the following ways: 1. Controlling the atmosphere to keep it from moisture and plenty of oxygen, for example by making the air environment free of oxygen by passing CO2 gas. 2. Prevent metals intersect with oxygen in the air as well as water. Prevention is done in the following way. A. Paint it The paint layer prevents direct iron contact with oxygen and water. Only if the paint is scratched or peeling, then corrosion begins to occur and can spread under the paint that is still intact. Examples that use this technique are on boats, bridges and cars. B. Gives oil, oil or fat The oil and grease layers prevent direct contact of iron with oxygen and water and should be applied periodically. Examples that use this technique are on the moving parts of the machine, like a car engine. C. Gives a plastic coating The plastic layer prevents direct iron contact with oxygen and water. Only if the plastic is peeling off, corrosion begins to occur. Examples that use this technique are on kitchen items, such as dryer racks.

The neutralization reaction is a reaction in which acids and bases react in an aqueous solution to produce salt and water. The liquid sodium chloride produced in the reaction is called salt. A salt is an ionic compound comprising a cation of a base and an anion of an acid. A salt is essentially any ionic compound that is neither an acid nor a base.

C. Reaction of Strong-Acidic Acid

When equal amounts of strong acids such as hydrochloric acid are mixed with strong bases such as sodium hydroxide, the result is a neutral solution. The reaction product does not have either acidic or alkaline characteristics. Here is the equation of the molecular balance reaction.

HCl (aq) + NaOH (aq) → NaCl (aq) + H2O (l)

The chemical reaction occurring in a water solution is more accurately represented by the net ion ion equation. The complete ionic equation for neutralizing hydrochloric acid with sodium hydroxide is written as follows:

H + + Cl- + Na + + OH- → Na + + Cl- + H2O

Since both acid and base are strong, they are fully ionized and so on written as ions, as NaCl is formed as a product. Sodium ions and chloride ions are the spectator ions in the reaction, thus producing the following reskai as a clean ionic reaction.

H + + OH- → H2O

All strong acid neutralization reactions with strong bases are clean ionic reactions of hydrogen ions combined with hydroxide ions to produce water.

What if the acid is a diprotic acid such as sulfuric acid? The equilibrium equation of molecules now involves a ratio of 1: 2 between acid and base.

H2SO4 (aq) + 2NaOH (aq) → Na2SO4 + 2H2O (l)

In order for the reaction to be fully neutralized, twice as much NaOH mole should react with H2SO4. The soluble sodium sulfate salt, and so on the same clean ionic reactions. Different mole ratios occur due to other polyprotic acids or bases with some hydroxides such as Ca (OH) 2.

D. Fermentation is the process of energy production in cells in anaerobic state (without oxygen). In general, fermentation is one form of anaerobic respiration, however, there is a clearer definition that defines fermentation as respiration in an anaerobic environment with no external electron acceptor.

Sugar is a common ingredient in fermentation. Some examples of fermented products are ethanol, lactic acid, and hydrogen. However, some other components may also be produced from fermentation such as butyric acid and acetone. Yeast is known as a material commonly used in fermentation to produce ethanol in beer, wine and other alcoholic beverages. Anaerobic respiration in the mammalian muscle during hard work (which has no external electron acceptor), can be categorized as a form of fermentation that produces lactic acid as a by-product. Accumulation of lactic acid is what plays a role in causing fatigue in the muscle.

. Alcohol fermentation

Alcohol fermentation is a reaction of conversion of glucose to ethanol (ethyl alcohol) and carbon dioxide. Organisms that play the role of Saccharomyces cerevisiae (yeast) for the manufacture of tape, bread or liquor. Chemical reaction:

C6H12O6 → 2C2H5OH + 2CO2 + 2 ATP

2. Fermentation of lactic acid

Lactic acid fermentation is a respiration that occurs in animal or human cells, when oxygen demand is inadequate due to overwork

Inside the lactic acid muscle cells can cause symptoms of cramps and fatigue. Lactates that accumulate as waste products can cause tired and painful muscles, but are slowly transported by blood to the liver to be converted back into pyruvate. Glucose is broken down into 2 pyruvic acid molecules through glycolysis, forming 2 ATP and 2 NADH.

3 Vinegar fermentation

It is an example of a fermentation that takes place in aerobic state. This fermentation is done by acetic acid bacteria (acetobacter aceti) with ethanol substrate. The energy produced is 5 times greater than the energy produced by anaerobic alcoholic fermentation.