Biodiesel production

The "sustainable energy" is the energy that is produced and used in ways that support long-term human development in the social, economic and ecological.

Access to energy, including sustainable energy, is inseparable from a sustainable future for the developing world. Access to energy transforms the lives of those who lack energy resources and improve their living standards.

Energy services have a profound effect on productivity, health, education, climate change, food security and water and communication services. Lack of access to clean energy, affordable and reliable hinders social and economic development. Some 1,400 million people lack access to modern energy, while 3,000 million depend on "traditional biomass" and coal as the main energy sources.

Biodiesel appears as an alternative to petroleum fuels, but no longer controversial.

This topic has aroused the curiosity of many people, and so I consider it is important that teachers of chemistry are informed about biodiesel production enterprises in our country. This is an important issue that can be worked in different years of high school.

the main producer of biodiesel production in Uruguay is the plant of the company ALUR. For further information about biodiesel production look at an interesting video in the following link: 

http://www.alur.com.uy/images/videos/2012/biodiesel/biodiesel-1.html

Spirometry: redox reactions

The alcohol digested by a person is not chemically modified in the bloodstream. As blood passes through the lungs, some of the alcohol molecules is immersed in air bags lung (alveoli), because of the alcohol in the blood is evaporated due to its high volatility. The alcohol concentration in the alveolar air is related to the concentration of alcohol in the blood.
Because alcohol exhaled in breathing can be determined by various mechanisms and through an established relation the concentration of alcohol in blood can be determined . This allows to know the relation of alcohol in blood without having a sample of it, but simply with breathing and get it.

The alcohol in  breath is examined using a device called a breath analyzer.

The chemical operation of these devices is explained by a redox reaction.
A driver's breath sample is introduced into the analyzer where it reacts with potassium dichromate in an acidic medium.
The reaction is represented by the following equation:

3CH3CH2OH + 2K2Cr2O7 + 8H2SO4___________  3CH3COOH + 2Cr2(SO4)3+2K2SO4+11H2O

In this reaction, ethanol is oxidized to acetic acid and chromium (IV) ion dichromate, reddish-orange ion is reduced to chromium (III), green. The intensity of the color change is directly related to the level of alcohol in exhaled air and therefore also in the blood.
Silver nitrate used is a catalyst which causes the reaction to go faster.

The theme redox reactions it would work only in the second year of high school where the student already has got various skills needed for the construction of this new knowledge.
I leave an activity where they can work the above.

Experimental Activity

Redox reactions

Previous activities:

> Find out about the alcohol content of different drinks usually consumed.

> Make calculations of the shots required to prepare 100ml of solution at different concentrations.

Objective:

> Explain the operation of the spirometer through redox reactions.

> Observe the color change that occurs in response to varying concentrations of alcohol

Rationale:

                                       > Redox reactions

                                       > Oxidizing agents, reducing

                                       > Alcohol

                                       > Limiting reagent

Materials:         

                       > test tubes

                       > Tweezers

                       > Bohemian glass

                       > Flask

                       > Burner

                       > Pipette

                       > Ethanol 95% v / v

                       > Potassium dichromate 5% m / v

                       > Distilled water

Procedure:

                   > Prepare 100 ml of an ethanol solution of 5% v / v, 10% v / v 20% v / v respectively.

                   > Place in 3 test tubes 10 ml of potassium dichromate 5% m / v

          > Place in 3 tubes the same volume of 0.5 ml of ethanol solution with different concentrations.

                   > Place the tubes in water bath for a few minutes and observe the changes

This practice is intended students to link the themes from a corpuscular view with macro phenomena. The concentrations of ethanol previously reacted are linked with different graduations of the most common beverages.

This is a practice that is not a quantitative but rather qualitative.

bibliography:

                 > Sanmarti, Neus "The design of teaching units" Autonomous University of Barcelona

                 > Laborde, Gustavo "designing lesson plans" and "Planning in Education"

                 > Atkins "principles of chemistry"

They were also used to support materials during the course of General Chemistry I

My conception of science

Once you set a theme or concept there are several ways to approach the teaching of it.

Personally, I consider appropriate to develop teaching strategies based on a model of conceptual change because this way the concept really can be assimilated.

A strategy based on conceptual change involves considering the previous ideas of students.

To change previous wrong ideas we need a methodology in which they figure out this ideas are not true actually. We force to face up situacions which these wrong concepts don't solve the problem and it's here when the new right concepts appear.This is the start to make change.

The teacher plays a key role in the process of teaching. They should not introduce concepts already finished or abstract but they should encourage them with a spirit of inquiry and guide them to construct knowledge.

It is necessary to take into account the student context in which this process takes place.

The teacher must be able to transcend the abstract idea of science to be applied in the day-by-day situations. Science should be used as a tool to understand the world around us and not as a set of abstract knowledge.

Chemestry teacher

From the origins of the universe, so far, a series of transformations have shaped our world. There are two key players in these transformations: matter and energy are converted into each other at every turn.

Every day, without realizing it, we use the transformations of matter and energy; for example when we turn the gas or firewood into heat through combustion.

Chemistry is the branch of science that studies matter and its transformations, and personally I consider it very attractive.

It's for this reason and for my vocation in teaching chemistry that I decided to follow this career. 

x

LOTI framework

The technology implementation is very important because it can enrich the teacher’s task and make easier the students learning. I consider that my level of implementation is quite low for different causes; a proof of this is my difficulty using this blog. However, I try to improve my performance day by day. 

                                                  

                                                   

Omega 3 and Omega 6:

Fats, as higher energy reserves, are highly useful for the organism. It is therefore useful to be present in the body in proper amounts.

The basic components of fats are fatty acids. Among them there are a variety of substances known as omega 3 and 6. Omega fatty acids are denominated as within the core for the reason that the human body does not produce. This causes that must be ingested through proper nutrition.

Scientific research has shown that, in the geographical areas where these acids are very present in the daily diet, levels of atherosclerosis and cardiovascular disease are just existing.

Analysis of food in these areas led to the conclusion that the common elements of these regional diets, fatty acids Omega 3 and 6, are responsible for such virtues.

The functions of omega 3

The fatty acids have an effect of decreasing the levels of cholesterol and triglycerides, and in turn reduce platelet aggregation in the arteries. This implies that the blood circulating platelets do not adhere to each other, thus preventing clot formation.

Other features of the Omega-3 highlights its intervention in the formation of cell membranes, make up most of the brain tissue being nerve cells are rich in Omega-3 fatty acids, and converted into prostaglandins, substances an important role in the regulation of the cardiovascular, immune, digestive, reproductive and have anti-inflammatory effects.

Fatty acids Omega 3 and Omega 6 are polyunsaturated fats appear as oils. Linoleic omega 3 and omega linoleic and arachidonic 6. As EPA and DHA in fish and seafood.

Foods containing omega 3 and 6

Fatty acids Omega 3 and 6 are found in high concentrations in fish, and to a lesser extent seed and vegetable oils such as flax, soybeans, pumpkin and walnuts. Its use reduces serum cholesterol levels, TAG, consecutive ischemic damage to heart attack and stroke by reducing the viscosity of the blood and blood pressure.

To prevent these types of conditions is useful consumption of 400 grams per week (two servings) of fish.

                                     What is DENSITY ?

DENSITY is a physical property of matter, as each element and compound has a unique density associated with it. Density defined in a qualitative manner as the measure of the relative "heaviness" of objects with a constant volume.

For example: A rock is obviously more dense than a crumpled piece of paper of the same size. 

A styrofoam cup is less dense than a ceramic cup.

Density may also refer to how closely "packed" or "crowded" the material appears to be - again refer to the styrofoam vs. ceramic cup.

                                              

Theory of meaningful learning of Ausubel:

For a long time thought that learning was synonymous with behavior change, this, because prevailing behaviorist perspective of educational work, but it can be said with certainty that human learning goes beyond a simple change of behavior leads to a change in the meaning of experience.

Educational psychology tries to explain the nature of learning in the classroom and the factors that influence these psychological foundations provide the principles for teachers to discover for themselves the most effective teaching methods, since trying to find means by "trial and wrong "is a blind procedure and therefore unnecessarily difficult and uneconomical (Ausubel: 1983).


Ausubel suggests that student learning depends on prior cognitive structure that relates to the new information, is meant by "cognitive structure", the set of concepts, ideas that an individual has in a particular field of knowledge and its organization .

In the process of learning orientation is vital to know the student's cognitive structure, not just about knowing how much information you have, but what are the driving concepts and propositions and their degree of stability.

       

The most amazing part of the human body

The brain

It's amazing the ability of the human brain that receives information from the outside world through the sensory system, which we receive through the senses and keep in our memory.
It is remarkable that the brain is capable of keeping information and bring it to light only when the person needs it.
Another great function that has the brain is to send instructions to cuepro through the motor system. This is responsible for making the whole body to function.
Finally the brain also controls how fast or as slow the heart has to go through the homeostatic system.

Story about the discovery of the atom

    The discovery of the atom was a very slow development.
    Democritus was the first to say that matter is composed of atoms, and that they were indivisible.
    Dalton later, in 1803 launched his atomic theory of matter. It said that all known matter is made up of atoms, and these were the smallest that could divide the matter is, they were indivisible.


I leave the link of a video so you can see the discovery of the atom and have developed different theories to the course of history.

http://www.youtube.com/watch?v=zX3jsE_ZYi4

Chemestry s Nobel Prize 2011

Dan Shechtman was awarded a Nobel Prize in Chemestry in 2011 by having proposed the quasicrystals theory. This fact has changed the way of understanding the solid structure.

Next I introduce a picture of quasicrystals, a paragraph of the official Nobel Prize page and its link.

I hope you will enjoy it.

"In quasicrystals, we find the fascinating mosaics of the Arabic world reproduced at the level of atoms: regular patterns that never repeat themselves. However, the configuration found in quasicrystals was considered impossible, and Dan Shechtman had to fight a fierce battle against established science. The Nobel Prize in Chemistry 2011 has fundamentally altered how chemists conceive of solid matter."




http://www.nobelprize.org/nobel_prizes/chemistry/laureates/2011/press.html

A GOOD LINK

http://phet.colorado.edu/en/simulation/glaciers

I want to share this link whit you, it`s about chemetry and physics`s interactive simulation.
I hope that you enjoy

Hello, I am Alfredo. 

Welcome to my new blog