video about chemistry

Explanation about show cause and effect of chemical reaction

https://www.youtube.com/watch?v=LwD4H7KIWYQ

TM 15: Using english to Predict rendement of product a reaction

When cooking, it's frequently handy to predict what will happen when we mix a bunch of ingredients together. For example, if we're interested in making a delicious new salad dressing, we would have a very small chance of making anything edible if we had no way of knowing which ingredients would have the greatest chance of succeeding.

Likewise, it's often necessary for chemists to predict the chemical reactions that will take place when two chemicals are combined. For example, if we're adding a chemical to a tank of toxic waste to stabilize it, we'd be very unhappy if we failed to predict an explosive reaction..

An easy way to predict what reaction will take place when two chemicals are mixed is to identify the type of reaction that's likely to occur when the chemicals are combined. Of course, we mentioned before that these types of reaction are arbitrary, but they do sometimes have a useful purpose.

Here are some tips you may find handy in helping to predict the type of reaction that will occur if you know only the reactants. Keep in mind that not all combiations of chemicals will result in a chemical reaction these tips are handy only for helping to predict what would happen should they happen to react.

  The theoretical rendement is calculated based on the number of moles of the limiting reagent. For this calculation, it is usually assumed that there is only one reaction involved. The ideal chemical yield value (theoretical rendement) is 100%, a value highly unlikely to be achieved in its practice. Calculate the percentage of rendemen that is by using the following equations percent rendemen = weight yield / weight of yield divided by the sample weight multiplied by 100%.              

Hint when trying to predict products of chemical reactions  
                   
First look for obvious precipitation reactions - two aqueous salt solutions mixed together with one of the salts containing an ion that quite often is insoluble (such as Ca, Fe, Ag, Hg, Pb). Then looks for other possible precipitation reactions in which one of the above ions is present in an aqueous salt but the other solution is an acid which might provide an anion (like sulfate or chloride) that could precipitate with the above ion. Next identify easy acid/base reactions - in which you have an easily identifiable acid (nitric, sulfuric, hydrochloric) and a hydroxide salt as the base. Now look for easily identifiable redox reactions in which O2 is a reactant and probably an oxidizing agent and the other reagent is a hydrocarbon, a carbohydrate, a metal, etc. The hydrocarbon and carbohydrate will react to form carbon dioxide and water, and the metal will react to form oxides. Finally look for other redox reactions, such as when you have a pure metal interacting with a ion of another metal or an acid which could dissolve it to form a salt of the metal.

example: 

In 50 grams of urea fertilizer (CO (NH2) 2) there are 21 grams of nitrogen. The purity of urea fertilizer is ...
Answer:
If you find a question that asks for purity then all you have to compare facts with theory.
FACT in Problem:
In 50 grams of urea fertilizer (CO (NH2) 2) there are 21 grams of Nitrogen (N)

THEORY:

 

COMPARE:

LEARNING IMPLEMENTATION PLAN (RPP)

LEARNING IMPLEMENTATION PLAN (RPP)
ELECTROLITE AND NON ELEKTROLITE SOLUTIONS

Education Unit: ………..
Subject: Chemistry
Class / Semester: X / Even
Time Allocation: 6 JP x 45 minutes (2 weeks)

A. CORE COMPETENCE
1.1 Living and practicing the religious teachings it embraces.  
1.2 Live and practice honest behavior, discipline, responsibility, care (mutual assistance,    cooperation, tolerance, peace), courteous, responsive, proactive. And show attitude as part of the solution to various problems in interacting effectively with the social and natural environment and in placing ourselves as a reflection of the nation in the association of the world.
1.3 Behave environmentally friendly and thrifty in utilizing natural resources.
1.4 Processing, reasoning, and presenting in the realm of concrete and abstract realms related to the development of the self-study in the school independently, and able to use methods according to scientific rules.

B. BASIC COMPETENCIES AND INDICATORS
2.1 Behave honest, disciplined, responsible, polite, cooperative, and proactive in conducting experiments and discussions.
2.2 Demonstrate critical, thorough, and consistent attitude in presenting and interpreting data.
3. Analyze the properties of electrolyte solutions and non-electrolyte solutions based on their electrical conductivity.
3.1. Mention the notion of electrolyte and non electrolyte solutions
3.2. Identify the properties of electrolyte and non-electrolyte solutions through experiments
3.3. Grouping the solution into electrolyte and non-electrolyte solutions based on their electrical conductivity
3.4. Explain the cause of the ability of the electrolyte solution to deliver electrical current
3.5. Describe that the electrolyte solution can be an ionic compound and a polar covalent compound.
4. Design, perform, and conclude and present experimental results to determine the properties of electrolyte solutions and non-electrolyte solutions.
4.1 Design an experiment to investigate the nature of the solution based on its electrical conductivity
4.2 Conducting electrical conductivity experiments on some solutions.
4.3 Observe and record experimental data of electrical conductivity in some solutions.
4.4 Determine the nature of the solution based on the electrical conductivity of the electrolyte solution and the non-electrolyte solution.
4.5. Conclude that the electrolyte solution may be an ionic compound or a polar covalent compound
4.6 Communicate experimental results of electrolyte and non electrolyte solutions

MEETING I:
a. Purpose
Through experiments students can
1. Mention the notion of electrolyte and non electrolyte solution
2. Identify the properties of electrolyte and non-electrolyte solutions by experiment
3. Group solutions into electrolyte and non-electrolyte solutions based on their electrical conductivity
4. Explain the cause of the ability of the electrolyte solution to conduct electrical current
5. Describe that the electrolyte solution may be an ionic compound and a polar covalent compound.
6. Design an experiment to investigate the nature of the solution based on its electrical conductivity
7. Conducting electrical conductivity experiments on some solutions.
8. Observe and record experimental data of electrical conductivity in some solutions.
9. Conclude the properties of the solution based on the electrical conductivity of electrolyte solution and non-electrolyte solution.
10. Concluding that the electrolyte solution may be an ionic compound or a polar covalent compound
11. Communicate experimental results of electrolyte and non electrolyte solutions

b. Learning Materials 

1. Electrolyte and Nonelectrolyte Solutions
Fact

Ø  Conductor

Ø  Isolator

Ø  Solvent

Ø  Dissolved

Concept

Ø  Solutionnv olution

Ø   Ionization reaction

Principle

Ø  The role of ions in the conductivity of electric solutions (archenius theory)

Ø  Electrolyte strength

Procedure

Ø  Steps of experimental conduct of electrical conductivity in solution

C. Learning Methods
Approach : Scientific
Method: Experiments.
Learning model: Problem Based Leaning

D. Media and Learning Resources
1. Periodic table and power point Advanced Learning Chemistry 1B Unit 6
2. Facil Book: Advanced Learning Chemistry 1B, Nana Sutresna, Grafindo Media Pratama, 2013

E. Learning Activities
1. Introduction

A. Condition students to learn and motivate students on "Electrolyte and Non-Electrolyte" materials.
B. Apersepsi: asks about electricity.
     "Where did the electric current come from?"
     "Do we need electricity in our daily lives?"
C. Delivering today's core learning on electrolyte and non-electrolyte solutions.

2. Core

A. Guiding students in groups for Observing

 • Review the literature on electrolyte and nonelectrolyte solutions.
Questioning
• Ask the question of whether all the solutions can conduct an electric current? Why is it that when a flood can be stung by electricity? What are the benefits of electrolyte solution in life?
Collecting Data (Experimenting)
• Design an experiment to investigate the nature of the solution based on electrical conductivity and present the results to equalize perception.
• Conducting electrical conductivity experiments on several solutions.
• Observe and record experimental data of electrical conductivity in some solutions. Associating (Associating)
• Analyze experimental data to infer the properties of the solution based on their electrical conductivity (electrolyte solution and non-electrolyte solution).
• Group the solution by type of bond and explain it.
• Conclude that the electrolyte solution may be an ionic compound or a polar covalent compound
Communicating (Communicating)
Presents reports of experimental results on the electrical conductivity of strong electrolyte solutions, weak electrolyte solutions, and nonelectrolyte solutions.

3. Closing
a. Encourage students to conclude solutions that can conduct electrical current and its causes.
b. Encourage students to reflect and discover the values that can be picked from today's activities.

F. ASSESSMENT

1. Engineering and Forms of Instruments

Instrument	Shape Technique
·          Attitude Observation	·         Attitude and Rubric Observation Sheets
·         Performance Test	·         Pick Test Test
·         Written Test	·         Test Description and Options
·         Portfolio	·         Portfolio Guidelines

No Aspect is assessed
1 Realizing the existence of God YMK.
2 Conduct disciplined and thorough experiments.
3 shows diligence and responsibility in learning and working both individually and in groups

2. Sample Instruments
   a. Attitude Observation Sheet

No	Aspek yang dinilai	3	2	1	information
1	Realizing the existence of God Almighty
2	Conduct disciplined and thorough experiments
3	shows diligence and responsibility in learning and working both individually and in groups

Assessment Rubric Attitude

No	Aspek yang dinilai	Rubrik
1	Realizing the existence of God Almighty	3: Realize nothing happens in this universe without the will of Almighty God. 2: Little realize that nothing happens in the universe without the will of Almighty God. 1: Not realizing that something that happens in this universe without the will of God Almighty.
2	Conduct disciplined and thorough experiments	3: Experiment with discipline and meticulous . 2: Experiment with discipline and but not thoroughly . 1: Do not experiment with discipline and thoroughly .
3	Showing curiosity	3: Always ask the teacher critically. 2: Sometimes ask teachers critically. 1: Never Ask teachers critically....

b. Portfolio Sheet
Science Portfolio book Advanced Learning Chemistru 1Bpage 11.
Firstly prepare tools and materials independently, ie 3 pieces of 1.5 volt battery; Duct tape; A very clean bowl; Salt solution of kitchen; 125 mL tap water; 125 mL distilled water; Aluminum foil measuring 30 cm x 18 cm which is folded elongated so that the long plate is not wide; Also make the shorter-sized aluminum foil plate; One flashlight bulb (1.5 volts); And two clothesline clips. With group creativity, you can replace these tools and materials with easily accessible tools and materials.
Next, arrange the battery with a positive pole touch the negative pole of the other battery. Strengthen the circuit with duct tape. Then, press the short aluminum foil plate on the battery's negative pole using the hand. Next, dip the short plate into the water in a bowl. Ask one of your group mates to hold the series of batteries in order to stay submerged in water. Clip the long aluminum plate into the lower bulb. Then, attach the bottom of the bulb to the battery's positive pole. Observe the reaction symptoms that occur in the bulb. Repeat this experiment using well water, sugar solution, or salt solution. Watch critically with your group's friends, what's going on? Why is that? Discuss the experimental results with your friends and teachers.

                  

STUDENT WORKSHEET

1. Purpose: Observe the symptoms of conductivity of electric current in various solutions

2. Tools and Materials

1.       Tools
1. 100ml glasses (1)
2. Rock battery 1.5 v (4)
3. Power cable 40 cm
4. Small Bulb (1)
5. Carbon Rod (2)

2.      Materials
 1. Well water
2. Salt salt solution
3. Vinegar solution to eat
4. Alcohol
5. Sugar solution
6. Lime water

3. Hasil Pengamatan

Solution	Symptoms on the light bulb	bulbs Symptoms on carbon rods
1.      Well water
2.      Salt salt solution
3.      Vinegar solution to eat
4.      Alcohol
5.    Sugar solution
6.    Lime Water

4. Questions
A. Any solution that shows the symptoms of light bulb?
B. What solutions show symptoms of bubbles on carbon rods?
C. What solutions do not show both symptoms above?

5. Conclusions
 What is the conclusion of the above experiment?

TM 14: Using english to report

Chemical reactions of egg shells and vinegar

CHAPTER I
PRELIMINARY

  1.1 Background
Eggs are a source of protein needed by the body. As an animal protein producer, eggs become a mandatory breakfast for those who work all day long, especially children of growth age. Eggs commonly consumed by the community are eggs produced from groups of aves or poultry. Eggs are protected by hard and dense shells. The usual part of eggs is consumed inside. Though egg shell can be processed into flour that can be consumed.
Vinegar or acetic acid is one of the foods that give a sour taste to food. Acetic acid is included in a class of weak acids used as a water softener and acidity regulator in the food industry. We must have seen a toothpaste advertisement showing an egg test and acetic acid or vinegar. In the ad we can see the eggs are soaked with vinegar into a mushy and the shells become cracked.
We definitely think the change in eggs is a way to get toothpaste products. Without us know the texture changes in eggs and eggshells were influenced by acetic acid. What substance is contained in the eggshell and why its texture is changed will be known based on observations of practicum chemical reactions of egg shells and vinegar.
Not only with vinegar, but with various types of acidic solutions, egg shells also cause different reactions. In other words, eggshells also have different effects on different types of acidic solutions. For example just like eggshells reacted with vinegar, of course, the reaction that occurs on the eggshell will be different from the chemical reaction process that occurs egg shell reacted with sulfuric acid.
In the experiments conducted by the authors, the authors reacted eggshells with various acidic solutions, such as the Javanese acid solution, orange solution, HCl solution, H2SO4 solution, and vinegar solution. Because the reaction that occurs on the egg shell against each of the different solutions, the authors also examine it in this paper in order to find out more about the process that occurs about chemical reactions.

1.2 Problem Formulation
4 What is the process that occurs in chemical reactions?
5 Why a chemical reaction can occur? What is the cause?
6 What happens to eggshells after reacting with acidic solutions?

1.3 Purpose of Writing
1. To find out how the process that occurs in chemical reactions.
2. To know why a chemical reaction can occur and what causes it.
3. To find out what happens to the eggshell after being reacted with acidic solutions.

1.4 Research Benefits
1. To learn, to know and understand all the lessons related to chemical reactions and how the process of chemical reactions occurs.
2. For teachers, to know and pay attention to the students to be creative in analyzing, understanding and working in the process of learning about chemical reactions and the process of chemical reactions.

CHAPTER II
LITERATURE REVIEW

2.1 Regarding Chemical Reactions
Chemical reactions are transformations / changes in molecular structure. This reaction can result in the incorporation of molecules to form larger molecules, dividing molecules into two or more smaller molecules, or controlling the atoms in the molecule. Chemical reactions always involve the formation or breaking of chemical bonds.
Chemical reactions are also a natural process that always produces inter-altered chemical compounds. 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.
Different chemical reactions are used together in chemical synthesis to produce the desired product of the compound. In biochemistry, a series of enzyme-catalyzed chemical reactions form the metabolic pathway, in which synthesis and decomposition are usually impossible in the cell.
Chemical reactions are the result of conversion of chemical compounds. Compounds that are initially involved with a chemical reaction are called reaction materials. The chemical reaction material is generally characterized by chemical changes, and produces one or more generally different results from the reaction material. From before, chemical reactions involve the movement of electrons in forming and breaking chemical bonds, although the general concept for chemical reactions, in the form of chemical equations, can be used for the transition of particles of unity, as well as nuclear reactions.
Different chemical reactions are used in chemical synthesis to get the desired result. In biochemistry, a series of chemical reactions are catalyzed by an enzyme that forms a metabolic pathway, and its synthesis and decomposition are usually impossible under conditions within the acting cell.

2.2 Regarding Eggs
Eggs are one of the animal food ingredients consumed besides trading, fish and milk. Generally the eggs consumed come from the types of birds, such as chickens, ducks, and swans. Eggs are food ingredients that are very familiar with our daily lives. Eggs as a source of protein has many advantages, among others, the amino acid content is most complete compared to other foodstuffs such as fish, meat, chicken, tofu, tempeh, and so on.
Eggs have a delicious flavor that is favored by many people. Eggs also function in a wide variety of food processing.In addition, eggs including food sources of protein are relatively cheap and easy to find. Almost everyone needs eggs (Mietha, 2008).
Eggs are one of the most complete food ingredients of nutrition. In addition, this food is also versatile because it can be utilized for various purposes. The composition consists of 11% egg shells, 58% white, and 31% egg yolks. Nutritional content consists of 6.3 grams of protein, 0.6 grams of carbohydrates, 5 grams of fat, vitamins and minerals in 50 grams of eggs (Sudaryani, 2003).

2.3 Regarding the Skin of the Egg and its Content
The eggshell is the outer layer of the egg that serves to protect all the egg parts from injury or damage (Anonymous, 2003). The formation of egg shells takes a very long time on the uterus in the oviduct. Calcium content during the first four hours ranged from 2.2%, which increased to 5.6% every hour for the next sixteen hours. Ayambetina uses the animal feed and calcium framework available, for the formation of the outermost shell of the egg. Approximately 47% of the calcium framework is diverted for the formation of the outer shell of the egg (Panda, 1995).
For laying hens, kandungankalsium must be higher as long as the cattle still produce eggs, karenakalsium is needed for the forming of the outer skin (Darmono, 1995). When viewed with a microscope then the egg shell consists of 4 layers:
1. Cuticle layer
The cuticle layer is a transparent protein that coats the surface of the eggshell. This layer coats the pores on the eggshell, but its nature still passable gas so that the exit of water vapor and CO2 gas.
2. Foam coating
This layer is the largest part of the eggshell layer. This layer comprises a protein and a lime layer comprising calcium carbonate, calcium phosphate, magnesium carbonate and magnesium phosphate
3. Mamilary layer
This layer is the third layer of an eggshell composed of cone shaped layers with a round or oval cross section. This layer is very thin and consists of woven proteins and minerals.
4. Membrane layer
This layer is part of the deepest layer of eggshell. It consists of a dual layer of membrane that envelops the entire contents of the egg. The thickness of approximately 65mikron (Nasution, 1997). The chemical composition of the eggshell consists of 1.71% protein, 0.36% fat, 0.93% water, crude fiber 16.21%, ash 71.34% (Nasution, 1997).
 Based on the results, chicken egg powder contains calcium 401 ± 7.2 gram or about 39% calcium, in the form of calcium carbonate. There is pulastrontium of 372 ± 161 μg, toxic substances such as Pb, Al, Cd, and Hg are present in small amounts, as well as V, B, Fe, Zn, P, Mg, N, F, Se, Cu, and Cr Schaafsma, 2000).

2.3 What is an Acidic Solution?

Acidic solution is an acidic solution. Acidic solution if dissolved in water will produce H + ions. The definition of acid according to the pictorial dictionary is a substance that forms hydrogen ions in solution; Containing hydrogen that can be replaced with metals to form salts. Some acids are corrosive and most acids can alter an indicator.
In the above information has been mentioned about the nature of acid, one of which is corrosive. What is corrosive? Have you ever noticed rust on iron? Do you know what is rust? The event of rust or commonly known to us as corrosion is one result of corrosion.
According to the pictorial dictionary (2000), Corrosion is a slow, destructive destruction of a metal due to the activities of chemicals such as atmospheric acid or oxygen, eg copper deposited in the open air will corroded and form a green layer. In addition there are several other properties of the acid that produces H + ions, PH <7, is corrosive, turning the Blue litmus into Red.
Here are some examples of acid solutions, namely: HCl (Chloride Acid), H2SO4 (Sulfuric Acid), CH3COOH (Acetic Acid / Acid Vinegar), orange juice, and others. Classification of acid solution, by its nature Acid solution is divided into 2 kinds, namely strong acid and weak acid. Strong acids are acids which when dissolved in water most or all of their molecules turn into H + ions. Strong Acid Examples: HCl, H2SO4, HBr, HI. Weak acid is an acid that when dissolved in water only a small part of its molecule turns into H + ion. Weak Acid Example: CH3COOH.

CHAPTER III
RESEARCH METHODOLOGY

3.1 Research Methods
The method used in this study is a descriptive method of analysis, which describes the process of chemical reactions that occur in eggshells when reacted with acidic solutions.

3.2 Place and Time of Research
1. Place of Research
This research was conducted at Chemistry Chemistry Room of SMA Plus Negeri 2 Banyuasin III.
2. Time of Research
The study was conducted on Wednesday exactly on September 9, 2015.

3.3 Data Collection Method
Methods of data collection conducted in this study are as follows:
1. Literature review
The collection of necessary information and data is obtained from books and the internet.
2. Observation
This study was conducted by observation or data collection through observation and recording of symptoms directly on the object of research (egg shell reaction to various solutions - solutions that are acidic)
3. Documentation
This study was conducted by taking a picture of the object of research (eggshell reacted with various solutions - the solution is acidic).

3.4 Data Analysis Method
Data analysis method used to analyze data result of this research is qualitative analysis method.

3.5 Research Methods
3.5.1 Tools and Materials:
- Tools:
1. Glasses of chemicals
2. Erlenmeyer Pumpkin
3. Funnel
4. Reaction tube shelf
5. The reaction tube
6. Spatula metal
7. Spatula glass
8. Pipette
9. Filter paper

- Material :
1. Eggshell
2. Vinegar to eat
3. Javanese Acid
4. Orange
5. H2SO4
6. HCl
7. Aquades

3.5.2 Working Steps:
1. Javanese acid is inserted into a glass of kmia, then mixed aquades and stirred using a metal spatula.
2. Javanese acid that has been mixed with aquades, then filtered using filter paper that folded into the funnel.
3. The funnel is then placed on top of Erlenmeyer flask and poured the solution of tamarind acid.
4. Take a filtered Javanese acid solution using a pipette, then put into a test tube.
5. Insert the eggshell into the acid solution using a metallic spatula.
6. Look at the reaction that occurs on the material that has been mixed in the test tube.
7. Do the same with HCl solution, H2SO4 solution, vinegar and citrus solution.
8. HCl solution, H2SO4 solution, and vinegar do not need to be added aquades. In this case, aquades only decampurkan with tamarind and citrus juice, so as to produce a solution of tamarind and orange solution.

CHAPTER IV
RESULTS AND DISCUSSION

4.1Results
During the experiment, the authors collected data through experiments performed. In this case, the authors record the observations of chemical reactions occurring on the material that has been reacted at the time of the lab. Here are the results of observations about experiments performed by the author:

No.	No. Materials That Observed	Results Observation
1.	Egg shell + orange juice + aquades	-        - The surface of the solution is a bit of foam. - The surface of the egg shell is a bit of foam. -Color of turbid white solution. - The egg shell is not lifted to the surface of the solution.
2.		-The surface of the solution is a bit of foam. - There is no foam on the surface of the eggshell. - Color of brownish solution. - The egg shell is not lifted to the surface of the solution.
3.	Eggshell + Vinegar	-The surface of the solution is a lot of foam.       - On the surface of the egg shell there is a lot of foam. - Color of clear solution. - The egg shell is lifted alternately to the surface of the solution.
4.	Egg shell + H2SO4	- The surface of the solution is a bit of foam. - There is no foam on the surface of eggshells. - The color of the solution is clear. - The egg shell is not lifted to the surface of the solution.
5.	Eggshell + HCl	- The surface of the solution is a lot of foam. - In the surface of the egg shell there is a lot of foam. - The color of the solution is clear. - The eggshell is immediately lifted to the surface of the solution as a whole.

4.2 Discussion   
1. What is the process that occurs in chemical reactions?
Chemical reactions are a natural process that always results in the conversion of chemical compounds. 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.
Different chemical reactions are used together in chemical synthesis to produce the desired product of the compound. In biochemistry, a series of enzyme-catalyzed chemical reactions form a metabolic pathway, in which synthesis and decomposition are usually impossible Chemical properties are characteristics of a substance stating whether the substance can undergo certain chemical changes.
Chemical change is a change that changes the identity of matter in a matter. In the chemical change formed a new substance. The occurrence of a chemical reaction can be known from the changes caused by the reaction. Some of these changes are the formation of sediment, the occurrence of color changes, the formation of gas, and the presence of temperature changes.
1. Chemical Reactions Produce Sludge
Around us there are many chemical reactions that can produce sediment. Reactions which include examples of chemical reactions that produce precipitates include the carbonate compound at the bottom of the pan when boiling water.
When lime water is blown, there will be a reaction between lime water and carbon dioxide from the breath. The occurrence of the reaction can be observed the formation of white calcium carbonate (CaCO3) that settles on the bottom of the glass if left for a while.
Precipitation by chemical reactions has long been used for water purification processes. The muddy well water mixed with mud can be clarified with the addition of alum. Tawas will tie the particles of mud particles to clot and eventually settle.
2. Chemical Reactions Produce Color Changes
Apples that are cut and left for a while, over time will turn brown. This color change indicates that the chemicals in apples have reacted with oxygen in the air. The reaction between the starch starch solution with iodine tintur can be known from the color change that occurs. Color clear starch solution, brown iodine. If both are mixed will form a blue color.
If added vitamin C then iodine will react with vitamin C to form other chemicals that are colorless. So the occurrence of chemical reactions can be known from the color changes that occur. Household tools made of metal, these objects will gradually change color. The tool of iron will rust so that it becomes black, copper tools will change color to greenish, the tool from silver will change color to black. The color change indicates that there has been a chemical reaction to the devices. The color of the clothes we wear will fade as it reacts with the chemicals contained in the detergent.
In the practicum performed by the author, a chemical reaction occurs when the egg shell changes to foam on its surface and causes it to rise above the surface of the solution. In this case, a chemical reaction has occurred in the egg shell because the egg shell reacts to an acidic solution.

2. What happens to eggshells after being reacted with acidic solutions?
The egg shell undergoes different chemical reaction processes in each of the reacted solutions. At the time of the practicum, the author has observed that when the shell is reacted with vinegar, the thing that occurs on the eggshell is that the egg shell has a lot of foam on its surface and the eggshell can rise to the surface of the solution by itself.
Another case with the reaction that occurs when the egg shell has reacted with Javanese acid, it happens that the teur skin does not experience any reaction or in other words, egg shell does not give any reaction while being experimented. However, why in one solution such as a vinegar solution can cause foam on the surface of the egg shell and cause the eggshell to lift to the surface of the solution?
 This is because acetic acid can bind calcium contained in the eggshell. Vinegar is categorized in acidic substances, meaning vinegar has the ability to damage some substances such as, calcium is the main component of the egg shell. Egg shells are mostly made of calcium carbonate, using acid then the skin is soluble, not only with vinegar but with HCL or H2SO4 any of these can occur.
However, why do bubbles arise when the egg is soaked with vinegar solution? That's because the gas bubbles that appear when the reaction takes place are the result of the reaction of vinegar and eggshell. The bubbles are carbon dioxide gas because after being felt by hand, the surface of the glass is warm.
However, What substance is the result of the reaction? Substances resulting from this reaction are calcium acetate ((CH 3 COO) 2 Ca}, carbon dioxide (CO 2), and water (H2O). This indicates that Vinegar has the ability to damage some substances such as, calcium is the main component of egg shell. Vinegar is needed in egg coloring, because vinegar and water react with a layer of protein molecules that cover the surface of the egg shell so that the surface becomes positively charged and attracts the molecules. Dye molecules that are negatively charged. Eggs added with vinegar in a color solution are more concentrated than eggs whose solution is not vinegar. Vinegar-soaked eggs are 20% larger in size because the vinegar solution seeps into the egg.

CHAPTER V
CONCLUSIONS AND SUGGESTIONS

5.1 Conclusion
From the experiments conducted by the author, obtained some conclusions:
1. Chemical reaction is a process that always produces changes in chemical compounds.
2. Chemical reactions can occur because they are caused by characteristics that cause chemical reactions, such as discoloration, resulting in precipitates, producing gas and producing temperature changes.
3. The eggshell will experience a chemical reaction to an acidic solution, but with different processes.