Thursday, August 30, 2012

Dizziness in the Classroom - CO2 accumulation

Many students have fallen sleep during a class, this is a proven fact, but, do you think it has to do with the subject being boring? The teacher being boring? or the student is tired and hasn't a good sleep the night before?

The solution for some teachers is to tell that student to go outside and go refresh his face with water so he can wake up, and it seems to work, but, is it really one of the reasons the ones i said above?


Studies have found that the main reason for dizziness and drowsiness in a schoolroom is the increase of Carbon Dioxide (CO2) in the classroom air, effect of a poor ventilation and air exchange and renovation. This means that educators wont have to keep feeling they are boring (even if they are sometimes, lets face the facts) or the subject itself is boring or the fact that the student is really tired.


The average person exhales up to 2 pounds of Carbon dioxide, this gas is colorless and odorless and cannot be monitored if its not by sensors. Some schools have already placed sensors connected to the ventilation system in order to have a controlled environment and keep the air always fresh to avoid Carbon Dioxide accumulations.

Technology has help the humanity in many ways, but, do you think its necessary to install these devices in order to keep a classroom fresh? These devices control and make decisions with the Fan and ventilation systems adjusting the speed and exchange rate, but wouldn't it be just enough to provide classrooms with proper ventilation and proper maintenance? most of the time the ventilation systems decay because or poor maintenance and the fact that the filters are never replaced or a broken fan is never fixed.

Some schools cannot afford these kind of equipment, for EACH classroom as it is necessary, but even if the school can in fact afford it, wouldn't it be smarter to invest part of that money in replacing the entire ventilation system for a efficient system and better maintenance personal? instead of investing the money on a device that will only monitor and adjust the speed of a fan? and taking in consideration that even these devices will still need a proper maintenance and proper calibration every year, adding an extra cost to the budget.

I could be mistaken, and I'm not taking in consideration the energy consumption, because having a controlled system will lead to a efficient energy consumption only using full power when its needed. Nowadays classroom have become more crowded meaning that the levels of CO2 will raise to a high point easily.

Ive read that recently scientist have made a better device to detect carbon dioxide, developing a cheaper system that can be used by schools no matter the budget, its been said that these new devices wont require constant calibration and this is an example that in the future, this technology could be affordable.

But other problem faced is the amount of students placed on a single classroom, this is another important fact that leads on accumulation of Carbon Dioxide.

So what you think? Let me know your opinion about this, Do you agree we should all take our desks and go outside and do our classes there?

Sunday, August 12, 2012

Acids Nomenclature Exercises

Ok, time to practice the Acids Nomenclature, this will help you through your school exams, and remember, anything can be achieved with a little practice.

Name these Acids with all 3 nomenclatures; remember to use the tricks we learned.


Name this Acid


Remember how to make Acid formulas? Now we just need to go backwards to figure out which oxidation number the metal is using. Take the oxygen subscript, multiply it by 2 and subtract the Hydrogen subscript.
Proper way tod etermine the oxidation number of the No metal on the Acid

Now that we know which it is, let’s find the correct suffix to use. It has 4 oxidation numbers:

+1 ----> Hip-----ous
+3 ----> -ous
+5 ----> -ic
+7 ----> Per------ic

Traditional nomenclature has this writing structure:


So we just need to fill the name of the Non-metal and the suffix

PerChloric Acid


Sulfur has a valence of +6 on this Acid (4x2) – 2 = 6

Sulfuric Acid              <--- Traditional


Nitrogen has a valence of +5.

Nitric Acid                 <--- Traditional


Chlorine has a valence of +1

Hypochlorous Acid                <--- Traditional


Carbon has a valence of +4

Carbonic Acid                                   <--- Traditional


Chlorine has a valence of +5

Chloric Acid                                 <--- Traditional

Thursday, July 12, 2012

Laboratory Glassware: Burettes

This Glassware is widely known, also called Burets, it has a particular shape.


The burette has a long cylindrical shape, filled with volumetrical graduations along the cylinder, it has a stopcock with a plug and a bore, made generally out of glass, borosilicate or pyrex. Pyrex burettes are rarely seen, pyrex was build to resist heat but this glassware is used for volumetrical purposes and precision is needed, this cannot be achieved if the fluid is hot, because it will eventually cool down, changing the graduation of the glassware and its density aswell, that’s why most of these graduated glassware come with specification about the temperature on which they have been calibrated.

The most common volume found is 25 and 50 ml. But there are 100 ml burettes aswell.


Used mainly in titrations, to dose an exact volume of a reactant on a certain reaction. Some use it to measure liquid volumes but its not recommended as there are other glassware on a science lab for those purposes.

The first time I learned how to use this glassware was on laboratory science courses, when I was just starting at the university, it has a particular procedure to use it properly.

More Laboratory Glassware

Saturday, July 7, 2012

Laboratory Glassware: Boiling Flasks

This Laboratory Glassware is also known as Florence Flask, some variations called them Round-bottom flasks.

It’s used to contain or hold liquids and fluids; the shape is very characteristic, it has a round bottom and a long neck, and some have conical ground glass joints in the top commonly used to other standardized fittings.Made of glass or heat-resistant borosilicate glass.
The round bottom makes it hard to keep them upright, reason why it is commonly held at the neck by clamps on a stand.

Two or Three-necked boiling flasks are common in most laboratories.


As its names describes, its used for boiling liquids, the shape allows a more uniform heating or boiling, they are most used on distillations on rotatory evaporators, they are also used on reflux processes of laboratory-scale synthesis.

\More Laboratory Glassware

Saturday, June 2, 2012

The Periodic Table of Metal

I was browsing through the web looking for nice looking periodic tables and never thought i would find something like this, i really liked it so i decided to share it here, i hope you guys enjoy it. There is a white version too. Click on the image to see it larger.

Source: I found it on this guy's gallery ilookingyou

Sunday, April 15, 2012

Learning about Chemical Reactions

For those having trouble learning about how and why some Compounds act the way they do, i found a nice video that could help you with this, you could show it to your teacher in school, im sure they will like it too. Enjoy

Friday, February 10, 2012

Solar Techonology

The energy of the light is part of your existence. Without it life wouldn’t have been able to grow, and if it suddenly ended, life would disappear.

The relationship between the man and the Sun has always been filled with mystery and confusion. Since the men started to consider the sun a God, the explanations about the light and energy we get from it were variants, but we have always known how to take advantage of its effects.

The first farmers discovered, many thousand years ago, the relationship that exists between the hours of sunlight exposure and the speed of growth of some vegetables, but until the scientists clarified the process of Photosynthesis, said relationship was difficult to explain.

Some villages in the ancient times came to develop mirrors and lens capable to concentrate the light, but besides on rare occasions, people only took advantage of some of the reflective and refractive properties of the light, without knowing how to explain the energetic properties.

 In places with high sun exposure times and clean atmosphere, is possible to obtain part of the domestic electricity from the Sun. Through big panels, provided with a high number of photovoltaic cells, its possible to transform the solar energy into electricity to warm the house, make run the appliances, get hot water and all those things we usually get thanks to the energy from the electric companies. All of this thanks to a clean and economic system.

The sunlight going mainstream

The human beings have learnt to use the sun light better. Little and big experiments have been developed to make our lives more comfortable. Greenhouses use the sunlight to maintain its elevated inner temperature; in cold weather places, the homes have big windows to use better the light and heat from the sun. There are experimental electric centrals that transform the energy through photovoltaic cells.

The invention of the artificial light


So far we have seen examples of how the solar energy can be transformed into other forms of energy. However, human beings also have learnt to produce light from other energetic sources.

Our ancestors discovered that anything that burns produces certain amount of light, but it took a long time to find materials that could burn slow enough and produce significant amount of light. The torches, the candles and candiles were the only acceptable result produced after thousand of years, until in the XIX century some experiments were developed to use the gas and petroleum as lighting systems. 

 At the end of that century a really effective system of artificial illumination was found: the light bulbs that could produce light from electricity. Inside there was a metal filament; when electricity flows, the filament heats ‘til incandescence and produces light. For the filament to not burn, Oxygen must be removed from the inside of the bulb. Many electric lamps have been developed; some don’t have filaments, but gases capable to emit light.

Thursday, January 12, 2012

Solar Powered Cars

Solar cells are capable of producing a reasonable amount of electric energy from solar light. This has stimulated the imagination of many creative people around the world.

One of the most attractive uses for the photo electricity –electricity produced by light– are the vehicles powered by solar energy. So far, tests on airplanes, boats and cars have been performed with different results. A light airplane, which had all the roof covered by solar cells capable of producing enough energy to move an electric engine, was able to fly over the English Channel. 

Each year on Australia an original race is celebrated where only solar powered cars run. The participants have to travel from side to side the Australian continent and most of them don’t finish. The average speed accomplished by these cars is between 50 and 80 Km per hour.

The disadvantage of vehicles directly powered by photovoltaic cells is that they only work well on places with a exceptionally clear and sunny weather.

As usually happens on the high technology business, Japan is one of the pioneers on solar energy applications to transportation. The main inconvenient of using solar energy on vehicles is the necessity of using heavy accumulators or batteries that occupy too much space. This is because of the need of store energy for the vehicle when there is no solar light available. The batteries store the energy when solar light is abundant.

A possible dream 

In the 60’s, experts around the world worked in a project that could look as science fiction. It involves launching an enormous space station to convert solar energy into electricity and send it to the earth in form of microwaves.
The space station would have 3 main parts: a solar collector of 6 Km long by 2.5 Km width, build of mirrors and photovoltaic cells; a energy central and a microwave transmitter. Despite its cost, an installation of this magnitude could be rentable on the long run thanks to the fact that the energy efficiency of solar cells is higher outside the earth’s atmosphere. This microwaves could be transformed into electricity again on earth. 

The microwave transmitter space station project has never go further than in paper, many hoped that this could have been the end of the fossil fuels. Nevertheless, some day we could have to give a chance to these exotic and crazy methods to obtain efficient energy for men.

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