Kamis, 25 Mei 2017

The last task of wahyu mujiasih (chemical bond)

The last task of wahyu mujiasih (chemical bond)

Okay, please watch my video on :
  https://www.youtube.com/watch?v=3AGmwpSqfpo&t=8s

Chemical bond

A chemical bond is a physics process that is responsible for the interaction of attraction between two atoms or molecules that causes a diatomic or polyatomic compound to be stable. The types of chemical bonds are as follows:

A. Ionic bonds and covalent bonds
The octet rule is that most atoms tend to have eight electrons in the outermost shell. Atoms with electrons are a bit like 1H, 2He, and 3Li. Tend to have two electrons on its outer shell (duplet rule).
To obtain a stable electron array (eight or two electrons) on the outer shell of existing atoms tends to release electrons, others tend to capture electrons.

If the outer electrons 1,2, or 3 atoms tend to release electrons.
If the outer electron of 4.5.6 or 7 atoms tends to capture electrons.
If the outer electron 8, the electron array is stable.

Based on the tendency of atoms to release or capture electrons, there are two main types of chemical bonds:
1. The bond of ions (electrotalen), the bond between positive ions and negative ions. This bond occurs due to the transfer of electrons from one atom to another that causes the formation of positive ions and negative ions which then tugs so that ion bonds form.
This bond usually occurs between metals (atoms that tend to release electrons) with non-metals (atoms that tend to capture electrons).

Compounds that have ionic bonds include:
• Alkaline group (IA) [except H atoms] with halogen groups (VIIA). Examples: NaF, KI, and CsF
• Group alkali (IA) [except H atom] with oxygen class (VIA). Examples: Na2S, Rb2S, Na2O
• Group of alkaline earth (IIA) with oxygen class (VIA). Examples of "CaO, BaO, MgS

2. Covalent bond, the bond that occurs due to the use of electron pairs together. In the covalent bonds each of the atoms binds contribute a large electron.
If the donated electron pair (for use together) is only one atom then a covalent coordination bond is formed.
A covalent bond occurs between the same non-metallic element compounds (both tend to capture electrons).

The various covalent bonds are as follows:
1. Single covalent bond
Is a covalent bond with the number of pairs of electrons used together amounted to a pair.
2. Twofold covalent bonds
Double covalent bonds have two pairs (4 pieces) of shared electrons.
3. Triple covalent bonds
Number of pairs of electrons used in covalent bonds 3 copies of the answer is 3 pairs (6 pieces of electrons).
Differences of ionic and covalent bonds are as follows:
A. Ionic bonds
• In a pure state it can conduct electricity.
• Melting point and high boiling point.
• Everything is solid at room temperature.
B. Covalent bond
• In pure state can not conduct electricity.
• Low melting and boiling points.
• There are dense, liquid, and gas.

Sabtu, 20 Mei 2017

RPP k13 about chemistry


RPP k13 about chemistry 


Unit of Education        : SMA N 17 KAB. TEBO
Subject                         : Chemistry
Program                       : IPA
Class / Semester           : XI / 1
Time Allocation           : 3 x 4 JP

A. CORE COMPETENCY
1.1  Living and practicing the religious teachings it embraces.
1.2  Living and practicing honest, disciplined, responsible, caring (polite, cooperative, tolerant, peaceful) behavior, courteous, responsive and proactive and showing attitude as part of the solution to problems in effectively interacting with the social and natural environment And in placing themselves as a reflection of the nation in the association of the world.
1.3 Understanding, applying, analyzing factual, conceptual, procedural knowledge based on his knowledge of science, technology, arts, culture, and humanities with the insights of humanity, nationality, state and civilization on the causes of phenomena and events, and applying procedural knowledge to A specific field of study according to his or her talents and interests to solve problems.
1.4 Processing, reasoning, and recruiting in the realm of concrete and abstract realms related to the development of self-study in schools independently, and capable of using methods according to scientific rules.

B. BASIC COMPETENCY
2.1 Recognize the regularity of hydrocarbons, thermochemicals, reaction rates, chemical equilibrium, solutions and colloids as a manifestation of the greatness of God YME and knowledge of the existence of such order as the result of creative human thought whose truth is tentative.
• Demonstrate scientific behavior (having curiosity, discipline, honest, objective, open, able to distinguish facts and opinions, resilient, conscientious, responsible, critical, creative, innovative, democratic, communicative) in designing and experimenting and discussing the realized In everyday attitude.
• Demonstrate co-operative, courteous, tolerant, peace-loving and caring about the environment and cost-effective in utilizing natural resources.
2.6 Understanding collision theory (collision) to explain chemical reactions.
2.7 Analyze the factors that influence the rate of reaction and determine the order of the reaction based on experimental data.
2.6 Present an understanding of collision theory (collision) to explain chemical reactions.
2.7 Design, perform, and conclude and present experimental results of factors affecting reaction rate and reaction order.

C. COMPETENCE ACHIEVEMENT INDICATORS
3.1 Explain the meaning of the reaction rate
3.2 Mention 4 factors affecting the reaction rate
3.3 Determining the order of the reaction
3.4 Determine rate constants and reaction rate equations
3.5 Presents the results of a discussion of the occurrence of chemical reactions based on the collision theory
3.6 Presents the results of the discussion on the meaning of reaction rates
3.7 Design an experiment to determine the effect of concentration, the surface area of ​​the touch surface, and the temperature on the reaction rate
3.8 Conducting an experiment to determine the effect of concentration, the surface area of ​​the touch surface, and the temperature on the reaction rate
D. LEARNING MATERIALS

4.1 Reaction rate

The reaction rate is the magnitude of the addition of the concentration of reaction time reactions or the amount of reduction of reagent concentration per unit time.
PA + qB rC + sD
VA = - (d [A]) / dt = reducing the concentration of substance A per unit time
VB = - (d [B]) / dt = reducing the concentration of substance B per unit time
VC = + (d [C]) / dt = addition of C substance concentration per unit time
VD = + (d [D]) / dt = incremental concentration of D substance per unit time
The ratio of the reaction rate of the substances according to the reaction coefficient ratio
VA: VB: Vc: V¬D = p: q: r: s
(Super-intensive learning resolution compilation team, 2016: 187).
The rate of a chemical reaction is the number of moles of reactants per unit volume that react in a given time unit. A negative sign is used if X is a reagent and a positive sign is used if X is a reaction product. The overall rate of a chemical reaction generally increases if the concentration of one of the reagents is increased. The relation of reaction rate and concentration can be obtained from the experimental data. For the reaction, A + B → product can be obtained that the rate of reaction can be directly proportional to [A] x and [B] y. (K) is the reaction rate law or the reaction rate equation, where k is the reaction rate constant, x and y are integers that express the order of x to A and the order of y to B, Whereas (x + y) is the overall reaction order (Prayitno, Vol. X, No. 1, January 2007: 29).

4.2 Factors affecting reaction rate

Here are some factors that affect the rate of reaction are:
Temperature / temperature
When the temperature is increased, the kinetic energy of the reacting substance particles will increase so that the particles will move faster. Thus the collision will become more frequent and the reaction rate will increase.
In general, if the temperature is raised 10 º C the reaction rate becomes twice as fast (time is reduced by half).
              
V1 = 2 ^ (ΔT / 10) × Vo or t1 = (1/2) ^ (ΔT/10) × to
(Super-intensive learning resolution compilation team, 2016: 188).

Catalyst (catalyst)
A catalyst or a catalyst is a substance which can speed up a reaction by making another way (a new reaction step) having a lower activation energy (Ea). The catalyst is considered not to react because at the end of the reaction will be found again in the same amount (super-intensive learning resolution team, 2016: 188).
Concentration (M)
The increase of concentration (M) of the reagent causes the number of reagent particles of volume union will increase. This allows the collision to occur more and more so that the reaction rate increases. This factor applies only to solvent-aqueous reagents (aq) and gas (g) (the super-intensive learning resolution compilation team, 2016: 188).

Surface area (LP)
This factor is specific to solid material reagents. The wider the touch area of ​​the solid, the more the number of impacts will occur and the reaction rate is higher. For the same amount, sub-solids with finer measurements have a wider surface area (super-intensive learning resolution team, 2016: 188).

Reaction Rate Equation
The rate equation of the reaction can only be determined from the experimental data, thus the reaction rate (in general) can not be expressed only from the equation of the reaction.
For the reaction (A + B → C), the result of the experiment showed that the reaction rate equation is:
V = k [
A] ^ m [B] ^ n

With v = reaction rate m = reaction order to A
             K = reaction rate constant n = reaction order to B

E. LEARNING ACTIVITY
Meeting 1

Learning steps
1. Initial Activity
• Teachers prepare students physically and psychologically.
• Teachers deliver apersepsi to students with the aim of guiding students' memories on material that supports the material to be studied.
Apperception: what is a chemical reaction? Still remember about molarity / concentration?
Motivation: Analyze the rate of reaction in chemistry with speed
• Explain the learning objectives (indicators) or basic competencies to be achieved 15 Minutes

2. Core Activities
• Teachers involve learners looking for information on the topic or theme of the material to be studied, ie the concept of Reaction Rate
Observe :
• Students observe images / videos of some chemical reactions
Questioning:
• Teacher asks what causes a chemical reaction?
• Teacher asks why there are fast-running chemical reactions, such as bombs and slow-running ones such as rusting?
• The teacher provides the learner's Worksheet that is related to the learning materials
 
Gathering information
• Students work on LKPD in groups
• Individually within the group of students collecting related information from various sources
• Students seek information about the causes of chemical reactions
• Students complete information on collision theory to explain chemical reactions
• Students discuss the meaning of reaction rate
 
Associate
• Students analyze collision theory to explain chemical reactions
• Student concludes understanding of reaction rate
 
Communicate
• Students present the results of a discussion of the collision theory that led to the occurrence of chemical reactions
• Students present the results of a discussion on the understanding of reaction rates
• Students listen to the teacher's explanation of the completeness of the concept of collision theory and the understanding of the reaction rate

3. Final Activities
• The teacher guides the students to conclude the material already covered
• Teachers and students reflect on collision theory
• The teacher gives a final test or evaluation to find out how far students understand the material that has been learned (instilling an independent and honest value).
• The teacher notifies and asks the student to read in relation to the material to be discussed at the next meeting communicatively.
• The teacher closes the lesson by saying good-bye.
Meeting 2
Learning steps
1. Initial Activity
• Teachers prepare students physically and psychologically.
• Teachers deliver apersepsi to students with the aim of guiding students' memories on material that supports the material to be studied.
Apperception: Prerequisite in the form of the question "what is the rate of reaction?
• Teachers motivate learners about the factual process of daily life related to the topic of discussion to arouse students' interest and curiosity.
Motivation: "Look at the picture on the slide, what can give an opinion about the image?
2. Core Activities

Observe :
• Students observe images / videos about fast and slow chemical reactions
• Students observe analogue images of the reaction with catalyst and reaction without catalyst
asking :
• Teacher asks what causes a fast-running chemical reaction, such as a bomb and some that run slowly like a rusty?
• Teacher asks anything that affects the rate of reaction in chemistry, so there are chemical reactions that run fast and some are running slow?
• Teacher asks how is the effect of catalyst in reaction rate?
• The teacher provides the learner's Worksheet that is related to the learning materials
Gathering information
• Students work on LKPD in groups
• Individually within the group of students collecting related information from various sources
• Students seek information about the causes of slow, fast-running chemical reactions, and what are the things that affect them
• Students discuss the influence of these factors on reaction rates and their relation to collision theory.
• Students discuss how the catalyst works / influence in the reaction rate
• Students conduct experiments to determine the factors that affect the reaction rate
Associate
• Students conclude the effect of concentration, touch surface area, and temperature on the reaction rate and its relation to the collision theory
• Students analyze the effect of catalyst in reaction rate
• Students connect the catalyst factor to the effect of the catalyst present in the industry
• Students analyze experimental data to determine factors affecting reaction rate
• Students observe and record experimental data of factors affecting reaction rate
Communicate
• Students present the results of a discussion of the effect of concentration, touch surface area, and temperature on reaction rates and their relation to collision theory
• Students present the results of a discussion of the effects of catalysts in reaction rates and their role in the industry
• Students present the results of data analysis obtained from the experiment
• Students generate reports of experimental results using correct grammar
• Students listen to the teacher's explanation of the completeness of the concept of the factors affecting the reaction rate
 
3. Final Activities
• Teachers and students reflect on the material they have taught.
• The teacher gives a final test or evaluation to find out how far students understand the material that has been learned (instilling an independent and honest value).
• The teacher notifies and asks the student to read in relation to the material to be discussed at the next meeting communicatively.
• The teacher closes the lesson by saying good-bye.
Meeting 3

Learning steps
1. Initial Activity
• Teachers prepare students physically and psychologically.
• Teachers deliver apersepsi to students with the aim of guiding students' memories on material that supports the material to be studied.
Apersepsi: Prerequisite in the form of question "what are the factors that affect the rate of reaction?
• Teachers motivate learners about the factual process of daily life related to the topic of discussion to arouse students' interest and curiosity.
Motivation: "a semngat and support provided by the teacher"

2. Core Activities
Observe :
• Students observe a slide show featuring a reaction equation and a table containing the reaction rate data of the reaction in various concentrations based on the experimental results
asking :
• The teacher asks how to state the relationship between the overall reaction rate and the concentrations of the substances involved in the reaction?
• Teacher asks How to determine the rate of reaction of a reaction equation?
• Teacher asks how to define the reaction order and rate constant?
• The teacher provides the learner's Worksheet that is related to the learning materials
Gathering information
• Students work on LKPD in groups
• Individually within the group of students collecting related information from various sources
• Students discuss ways to express the relationship between the overall reaction rate with the concentrations of the substances involved in the reaction.
• Students discuss how to determine the equation of reaction rate, reaction order and reaction rate constant
Associate
• Students process the experimental data provided (in LKPD) to determine the order of the reaction, the reaction rate constant and the rate equation of the reaction
• Students cultivate and analyze experimental data provided to graph the reaction rate
Communicate
• Students present the results of discussion on how to determine the equation of reaction rate, reaction order and reaction rate constant (answer matter in LKPD)
• Students present graphs created based on data processing that has been done
• Students listen to the teacher's explanation of the completeness of the concept of collision theory and the understanding of the reaction rate

4. Final Activities
• Teachers and students reflect on the material they have taught.
• The teacher gives a final test or evaluation to find out how far students understand the material that has been learned (instilling an independent and honest value).
• The teacher notifies and asks the student to read in relation to the material to be discussed at the next meeting communicatively.
• The teacher closes the lesson by saying good-bye.

F. ASSESSMENT, REMEDIAL LEARNING AND WORKING

1. Type / assessment techniques
• Assessment of Attitude
Observation
• Knowledge Assessment
•Written test :
• Selecting an answer:
Multiple choice
• Supplying answers:
Description
• Skills Assessment
• Products

2. Assessment Instruments

3. Remedial and Enrichment Learning

2. SOURCE AND MEDIA LEARNING ASSESSMENT

A. Learning Resources
Chemistry Package SMA: Sudarmono, Unggul. 2013. Chemistry For SMA / MA Class XI Group of Mathematics and Natural Sciences. Jakarta: Erland.

Super-intensive learning resolution compilation team.2016. Super Intensive Learning Resolution.Jambi: Ganesha Operation

Prayitno, January 2007, Chemical Kinetics Study Mathematical Model of Cadmium Reduction Through Reaction Rate, Constance And Order Reaction In Electrochemical Process.volume X, No.1.Journal (online)

B. Media / Learning tools
• Infocus / power point
• Student Work Sheet (LKPD)
• Experimental tools & materials


Kamis, 18 Mei 2017

Predict Rendement of Product a Reaction


Predict Rendement of Product a Reaction 

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. [1] 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. The theoretical rendement is calculated based on the number of moles of the limiting reagent. For this calculation, it is usually assumed 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 percent of rendemen that is by using the following equations percent rendemen = weight yield / weight of yield divided by the sample weight multiplied by 100%
In determining the direction of a chemical reaction we must rely on an understanding based on a number of factors, and contributions that are not always easy to assess. Although the assessment is prone to error, but it is usually reliable where it seems reasonable to try, and that is certainly to answer ignorance.
In predicting chemical reactions there are several known factors such as, if the free energy of a reaction is known, then there is no problem predicting a chemical reaction. Then if only enthalpy changes are known, then predictions usually apply to room temperature but are more or less reliable as well for higher temperatures. If the reaction occurring in the solution and the oxidation potential of the involved compound is known then the prediction is relatively simple, and this oxidation potential buys a rough guide for possible reactions in the absence of a solvent. If the equilibrium constant is known, relating to ΔG0 = - RH in K gives us a change of free energy. But information like this is still lacking, so we must rely on our understanding of the preceding principles. For chemical reactions at room temperature the expected entropy changes are not so great that the relative strength of the reactants and the products produced will guide the course of the reaction. Here are the rules that may be useful and will be used.
 
Reactions tend to occur where the bonds of the orbital and some of the electrons are available and allow for attractive tensile interactions between atoms.

The types of reactions that are predicted by this kind are most only some of them as follows:
(1) Synthesis - a direct combination of elements or compounds,
(2) Substitution - transfer of one element or compound, from excessive complex combinations with other elements or compounds, and
(3) Metathesis - double decomposition, or exchange partner.

In chemistry, the Le Chatelier principle, also called Le Chatelier or "Equilibrium Law", can be used to predict the effect of changes in conditions of chemical equilibrium. This principle is named after Henry Louis Le Chatelier and sometimes from Karl Ferdinand Braun who discovered this principle independently. This principle can be expressed as:
When a system at equilibrium changes its concentration, temperature, volume, or pressure, the system adjusts (partially) itself to eliminate the effect of applied change and a new equilibrium is reached.
In other words, every time the system is in equilibrium disturbed the system will adjust in such a way that the effect of the change will be canceled.
This principle has various names, depending on the disciplines that use them (see homeostasis, a term commonly used in biology). The Le Chatelier Principle also serves as the basis for more general observations in society, [1] which roughly state that:
Any change in the status quo will produce the opposite reaction of the system in question.
In chemistry, this principle is used to manipulate the results of a reversible reaction, often increasing the reaction yield. In pharmacology, the binding of the ligand at the receptor can shift the equilibrium according to Le Chatelier principle, so as to explain the various phenomena of activation and desensitization of the receptor. [2] In economics, this principle has been generalized to help explain the price balance of an efficient economic system.
Example:
1. 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: