As I said in the introduction I created this blog as part of an assignment in my English class and today is the conclusion of this project. Basically, I am very grateful and satisfied to have the opportunity of share information about the field that I am studying. I have to say that I learned a lot of this experience and I improve some skills and knowledge about different fields related to Chemistry.
I cited from my introduction: Chemistry Around Us is the title of this blog and I named like that because I am member of the American Chemistry Society and as members we say: “Chemistry is not limited to beakers and laboratories. It is all around us, and the better we know chemistry, the better we know our world.”-ACS. Definitely I could prove that there is a lot of things that we can study that are relate to chemistry and we do not have to be inside the laboratory. Also, as we saw during all these weeks, we are every day exposed to chemical behaviors of the nature...We just have to open our eyes and be curious. Chemistry is around and inside in all of us!!
Finally, I feel glad of comply my purpose with this blog. And I hope that I have catched all your atention and that you understood and learned a lot as much as me. Today is the conclusion of this blog project but is not the end of new information and discoveries in chemistry neither the information that I wrote is the blog is the unique information of this field. Therefore, I want you to reflect all the time about the news and share it with your social cycle. At the end, you, all the people around you including me, that see or heard the information that you are sharing, ALL OF US will be able to understand better the world in where we all live.
Now, I invite you to see the videos below and read the information that I already shared every day (in the case that is your first time visiting this blog). If you have information to share or questions, let me know!! To me is important be in contact and share knowledge to maintain the world informed.
Hello guys! As we know any technology is an important tool in science. Chemistry is not the exception. In fact there is an important sub career of Chemistry that integrates this science, math and the technology of computer programs and data base to obtain results, predict or create models. Today, I am going to talk about Computational Chemistry and I will explain some chemical properties that were analyzed and results that I personally obtained during a research project that I did this semester.
The term computational chemistry is generally used when a mathematical method is sufficiently well developed that it can be automated for implementation on a computer (John Wiley & Sons, Inc. 2001). Models, which are a simple way of describing scientific results are commonly used in this type of science field. Those models are made with a wide range of diverse computational programs. The primary focus of computational chemistry is solving chemically related problems by calculations. Although a computer is not able to do all the work a scientist can perform, computational chemistry has the ability to take big amounts of data and organize it effectively resulting in visual graphs, which help understand molecule interactions better; this being one of the biggest contributions from this field. There’s a wide range of information used in science (especially chemistry) that is able to be applied in computational chemistry. For example, it helps to answer questions about certain molecules like:
1. Which geometrical arrangements of the nuclei correspond to stable molecules?
2. What are their relative energies?
3. What are their properties (dipole moment, polarizability, NMR coupling constants, etc.)?
4. What is the rate at which one stable molecule can transform into another?
5. What is the time dependence of molecular structures and properties?
6. How do different molecules interact? (John Wiley & Sons, Inc. 2007).
Also, computational chemistry is useful when it comes to determining if an experiment with certain molecules would be viable. Since it can be used to determine how different molecules interact in various terms like polarity and electronegativity, before investing time and money in an experiment a scientist is able to use computational chemistry in order to have an idea of how (and with molecules) the experiment should be followed.
Programs like R studio and Gabedit (ORCA), are very useful in the field of computational chemistry; both of them having a different way of translating the chemical and mathematical information. R studio being more focused towards the mathematical analysis with graphs of molecules that are built with Gabedit which is used in order to have a more visual experience of those already built chemical molecules and its various interactions.
The basics of any computer program consist of a doing a few simple tasks such as:
1. Performing a mathematical operation (adding, multiplying, square root, cosine,) on one or two numbers.
2. Determining the relationship (equal to, greater than, less than or equal to, . . .) between two numbers.
3. Branching depending on a decision (add two numbers if N > 10, else subtract one number from the other).
4. Looping (performing the same operation a number of times, perhaps on a set of data).
5. Reading and writing data from and to external files. (John Wiley & Sons, Inc. 2007).
Specifically, in my research project certain chemical properties of organic compounds were analyzed, such as: polarity, electronegativity, dipole moment, intermolecular force and redox potential. Polarity is the lack of symmetry in terms of molecular charges. Electronegativity being the attraction of a given atom for the electrons of a covalent bond while an intermolecular force is the force applied in those attraction and repulsion acts between molecules (Jane Reece et al. 2014). Dipole moment is the mathematical product of the separation of the ends of a dipole and the magnitude of the charges and a redox potential is the tendency of molecules to be reduced (acquire electrons).
If you want to read more about this field go to my references. Do not forget to see the images below! (those images are part of my product in the research)
Thank you,
Stephanie
GRAPH CREATED WITH R STUDIO PROGRAM: POTENTIAL ENERGY OF DIFERENTS MOLECULES
MOLECULES CREATED WITH GABEDIT
References:
Computational Chemistry [Internet]. [Updated 2001]. J. Wiley &
Sons inc.; [cited 2016
May
29]. Available from: http://www.enu.kz/repository/repository2014/Computational-chemistry.pdf
Introduction to Computational Chemistry [Internet]. [Updated
2007]]. J. Wiley $ Sons
inc.;
[cited 2016 May 29]. Available from: http://karin.fq.uh.cu/qct/books/Jensen_Introduction%20to%20Computational%20Chemistry%202nd%20ed.pdf
Lynch E, Speelman A, Curry B, Murillo C, Gillmore J. 2012.
Expanding and Testing a
Computational Method for Predicting the Ground
State Reduction Potentials of Organic Molecules on the Basis of Empirical
Correlation to Experiment. ACS. 77(15):6423–6430.
Méndez Hernández D, Gusta D, Moorea T, Gillmorea J,
Montano L, Moore A, Mujica,
V.
2015. Building and testing correlations for the estimation of one-electron
reduction potentials of a diverse set of organic molecules. Physical Organic
Chemistry. 28(5):320–328.
Reece J, Urry L, Cain M, Wasserman S, Minorsky P, Jackson R. 2014.
Campbell
Hello guys, remember in a previous entry that I was talking
about Biochemistry? I have to say that I found good news about a discovery in this
field that I want to share with you today.
First, let’s recap what is biochemistry? Biochemistry is
the branch of science that explores the chemical processes within and related
to living organisms. It is a laboratory based science that brings together
biology and chemistry. By using chemical knowledge and techniques, biochemists
can understand and solve biological problems.
In this field, according
to a controversial new study by scientists and researchers at the University of
Georgia in the United States found that de obesity can be provoked by environmental
chemical conditions. The exposure to
some chemicals found every day in cleaning products, cosmetics and other types
could affect the amount of fat stored in the body.
Phthalates are one of the groups of substances that pollute
more frequently households. They are substances of priority if we want to
prevent health problems at home. They present in many products, from plastic
objects soap, to nail polish. But an increasing number of analysis shows that
these substances could be damaging the health of people, argues Lei Yin,
University of Georgia (UGA) in the US city of Athens, and co-author of the
research. According to her, the phthalate exposure could be associated very
closely with the increased incidence of certain types of diseases, including
obesity.
As we know, obesity is currently one of the major
problems in industrialized nations, and of course, the development of such
obesity is contributed by both genetic components as food. However, as
indicated Xiaozhong "John" Yu, co-author of the study, environmental
exposure may also play a significant role.
Since it had found levels of phthalates in human fluids in
previous studies, the research team wanted to see if one in particular commonly
known as BBP, had an effect on fat accumulation in cells. They used mouse cells
to create in vitro models and with those models they could analyze how exposure
to BBP affected the lipids place inside them. Some phthalates have been demonstrated
that cause reproductive toxicity when exposure to them reaches high levels, but
the link between a modest level of exposure, such as with BBP, and undue weight
gain had not yet been thoroughly explored. The results of experiments on investigation
indicate that the BBP caused a response in cells that promotes accumulation
therein lipid droplets in such high amounts suggesting that BBP exposure could
lead to obesity.
If you are want additional information of the research read the abstract of the research or go to references, copy and paste the links. Remember see the image and video below!!
Thank you, Stephanie R.
Abstract:
Benzyl butyl phthalate (BBP) has been known to induce developmental and reproductive toxicity. However, its association with dysregulation of adipogenesis has been poorly investigated. The present study aimed to examine the effect of BBP on the adipogenesis, and to elucidate the underlying mechanisms using the 3T3-L1 cells. The capacity of BBP to promote adipogenesis was evaluated by multiple staining approaches combined with a High Content Cellomics analysis. The dynamic changes of adipogenic regulatory genes and proteins were examined, and the metabolite profile was identified using GC/MC based metabolomic analysis. The High Content analysis showed BBP in contrast with Bisphenol A (BPA), a known environmental obesogen, increased lipid droplet accumulation in a similar dose-dependent manner. However, the size of the lipid droplets in BBP-treated cells was significantly larger than those in cells treated with BPA. BBP significantly induced mRNA expression of transcriptional factors C/EBPα and PPARγ, their downstream genes, and numerous adipogenic proteins in a dose and time-dependent manner. Furthermore, GC/MC metabolomic analysis revealed that BBP exposure perturbed the metabolic profiles that are associated with glyceroneogenesis and fatty acid synthesis. Altogether, our current study clearly demonstrates that BBP promoted the differentiation of 3T3-L1 through the activation of the adipogenic pathway and metabolic disturbance.
Hello guys!!!, remember the last post about the periodic table? I found interesting news about the periodic table that I want to share with you today. This good news is also an inspirational example that we should always have in mind that we can discover important things in our world.
There is a lot of persons that work hard every day to find new elements of the periodic table and it was possible found them. In Japan, Russia and the US have spent several years gathering enough evidence to convince experts from Iupac and its physics equivalent, the International Union of Pure and Applied Physics, of the elements’ existence. They confirmed four new elements with atomic numbers of 113, 115, 117 and 118. Now, the seventh row of the periodic table is complete.
Here some of the properties of those elements:
· The four are highly unstable super heavy metals that exist for only a fraction of a second. They are made by bombarding heavy metal targets with beams of ions, and can usually only be detected by measuring the radiation and other nuclides produced as they decay.
· Element 113: currently known by its placeholder name ununtrium, is the first to be discovered in east Asia. It was created by Kosuke Morita’s group at the RIKEN Nishina Center for Accelerator-based Science in Japan, by firing a beam of zinc-70 at a target made of bismuth-209. The group first claimed to have created the element in 2004, but there was still some uncertainty at that time because of the instability of one of its decay products. They followed up these experiments with more convincing evidence in 2012.
· Elements 115 (ununpentium) and 117 (ununseptium) were discovered by groups collaborating across three institutions, Lawrence Livermore National Laboratory in the US, the Joint Institute for Nuclear Research in Russia and Oak Ridge National Laboratory in the US. The Lawrence Livermore-Joint Institute for Nuclear Research collaboration is also credited with having fulfilled the criteria for discovering element 118 (ununoctium) in work published in 2006.
· Now that the elements have been officially discovered, the institutions responsible will get to choose permanent names for them. But it will be a while before the textbooks and posters can be updated, as the new names and symbols will have to be approved by the inorganic chemistry division of Iupac and submitted for public review. Various rules govern the names that can be given to new elements, which can be inspired by nature, mythology, people, properties or places.
· ‘The symbol is particularly important,’ says Soby. ‘They have to go through all the archives to check if it has ever been used before. It has to be unique.’ She adds that the timing is hard to predict, but estimates the process will take between four and six months.
These groups and others are now likely to turn their attention to elements beyond the seventh row. This presents fresh challenges, partly because the targets used for bombardment experiments would have to be made of super heavy, short-lived elements themselves. So far, no one claims to have discovered 119 or any elements heavier than it. Researchers are hopeful that an ‘island of stability’ may exist beyond element 118, allowing production of further super heavy elements, although exactly where this island can be found or whether it exists at all is still a matter of debate. ‘We just don’t know when that [sighting] will be … it could be next week, it could take a year or 10 years even when someone claims a discovery they have to prove it,’ says Soby. ‘It’s a great unknown right now.’
Do not forget see the video, See you next week, Stephanie R.
The majority of persons when I talk about
chemistry spontaneously think on a periodic table. The reason of that is because
chemistry studies the elements which are de basis unit of the matter. It is very
important know about the periodic table no matter if you will study any career
different of chemistry. The periodic table provides a lot of information that
help to understand the elements behavior and why they interact the way they do
to create or produce beautiful things of the nature. Basically, we all need go
to the periodic table to understand the how the world works. Today, I am going
to talk about the periodic table and a big part of the information that it provide
us.
The periodic table: The periodic table of the
chemical elements displays the organizing principles of matter. The table is a
tabular depiction of the chemical elements and their characteristics. Russian
chemist Dmitri Mendeleev is generally credited with the invention of the
periodic table. The layout of the table has been refined and extended over
time, as new elements have been discovered and new theoretical models have been
developed to explain chemical behavior.
·Each
element is placed in a specific location because of its atomic structure.
·Each
row and column has specific characteristics. The elements found in column share
certain similarities and the elements in rows share different characteristics.
·When
you look at the periodic table, each row is called a period. All of the
elements in a period have the same number of atomic orbitals. There is a
maximum of seven electron orbitals which is also the number of rows in the
periodic table.
·The
periodic table also has a special name for its vertical columns. Each column is
called a group.
·The
elements in each group have the same number of electrons in the outer orbital. Those
outer electrons are called valence electrons and they are involved in chemical
bonds with other elements. They are responsible of the chemical reactions.
·As
you keep counting the columns, you'll know how many electrons are in the outer
shell. But there are exceptions to the order when you look at the transition
elements, which are the elements from column 3 to 12. Sometimes they are
identifies as columns B and the others that are not transition metals are
identified as column A.
·Transition
elements add electrons to the second-to-last orbital.
·Groups
1-2 (except hydrogen) and 13-18 are termed main group elements.
·Main
group elements in the first two rows of the table are called typical elements.
·The
first row of the f-block elements (That are usually located below the table) are
called lanthanoids. The second row of the f-block elements is called actanoids.
·The
following names for specific groups in the periodic table are in common use:
oGroup
1: alkali metals
oGroup
2: alkaline earth metals
oGroup
11: coinage metals (not an IUPAC approved name)
oGroup
15: pnictogens (not an IUPAC approved name)
oGroup
16: chalcogens
oGroup
17: halogens
oGroup
18: noble gases
· Metals: In the periodic table, you can see a stair-stepped line starting at Boron (B), atomic number 5, and going all the way down to Polonium (Po), atomic number 84. Except for Germanium (Ge) and Antimony (Sb), all the elements to the left of that line can be classified as metals. These metals have properties that you normally associate with the metals you encounter in everyday life: o They are solid (with the exception of mercury, Hg, a liquid).
o They are shiny, good conductors of electricity and heat.
o They are ductile (they can be drawn into thin wires).
o They are malleable (they can be easily hammered into very thin sheets).
o Metals tend to lose electrons easily. When they lose electrons and as a superscript number with a positive sing like Mg2+, they are called cations.
· Nonmetals: Except for the elements that border the stair-stepped line, the elements to the right of the line are classified as nonmetals (along with hydrogen). Nonmetals have properties opposite those of the metals: o The nonmetals are brittle, not malleable or ductile, poor conductors of both heat and electricity, and tend to gain electrons in chemical reactions. When they gain electrons and as a superscript number with a negative sing like O2-, they are called anions.
· Metalloids: The elements that border the stair-stepped line are classified as metalloids. The metalloids, or semimetals, have properties that are somewhat of a cross between metals and nonmetals. o Metalloids tend to be economically important because of their unique conductivity properties (they only partially conduct electricity), which make them valuable in the semiconductor and computer chip industry.
Finally, as we can see there is a lot of information that the periodic table can provide us. I exhort you to see the image and videos below. If you have questions or doubts let me know.
My future career goals are to get accepted in a
Graduate school for study MD and PhD in Biochemistry. But no matter what are
your future goals is important search information and have knowledge about the
field that you want to study. Now, let’s talk about briefly how this idea of study
biochemistry evolved and what is this field.
Briefly, this idea evolved in this way:
I have to say that my parents suffer fibromyalgia
disease. This disease does not have cure and it can be hereditary, etc... I
took a class of chemistry and was my lab teacher the person who inspired me to
study biochemistry to can help my parents. I like biology and chemistry so why
not? Then I look for information and I concluded definitely to study it.
Biochemists have to understand both the living world
and the chemical world. Even if you don’t want to become a biochemist, you'll
still have to understand atoms and molecules as a biologist. The key thing to
remember is that biochemistry is the chemistry of the living world. Plants,
animals, and single-celled organisms all use the same basic chemical compounds
to live their lives. Biochemistry is not about the cells or the organisms. It's
about the smallest parts of those organisms, the molecules. It's also about the
cycles that create those biological compounds.
In other
words, biochemistry is the branch of science that explores the chemical
processes within and related to living organisms. It is a laboratory based
science that brings together biology and chemistry. By using chemical knowledge
and techniques, biochemists can understand and solve biological problems. Biochemistry
focuses on processes happening at a molecular level. It focuses on what’s
happening inside our cells, studying components like proteins, lipids and
organelles. It also looks at how cells communicate with each other, for example
during growth or fighting illness. Biochemists need to understand how the
structure of a molecule relates to its function, allowing them to predict how
molecules will interact.
Biochemistry
covers a range of scientific disciplines, including genetics, microbiology,
forensics, plant science and medicine. Because of its breadth, biochemistry is
very important and advances in this field of science over the past 100 years
have been staggering. It’s a very exciting time to be part of this fascinating
area of study.
What do
biochemists do?
· Provide new ideas and experiments to
understand how life works
· Support our understanding of health
and disease
· Contribute innovative information to
the technology revolution
· Work alongside chemists, physicists,
healthcare professionals, policy makers, engineers and many more professionals
To conclude, my purpose to show you my
experience is because sometimes we know that we like more than one field and we
think that we cannot fusion them or study them all. That is totally false!! Now
I exhort you to look for information of all the fields that you like and see
how you can mix them because that is totally possible.
Do not forget see the video and if you want to
know more about biochemistry go to my references. (Copy and paste the link)
We all can be important persons in science or other fields. We all can get the inspiration of something and create innovate things that are important for the humanity. I am going to present a resume of a new of C&NE that is an example of inspiration in simple things.
Gecko feet are covered with microscopic, spatula-shaped hairlike features that allow them to run up walls and across ceilings. The millions of microhairs are called setae. Each seta is between 30 and 130 micrometers long and branches out to end in several hundred flattened tips called spatulae. This unique structure allows the gecko’s toes to have unusually close contact with the surfaces it climbs. The close contact allows intermolecular forces which are significant at short distances, to hold the gecko to the wall.
As we know, molecules can attract each other at moderate distances and repel each other at close range. The attractive forces are collectively called "van der Waals forces". Van der Waals forces are much weaker than chemical bonds, and random thermal motion around room temperature can usually overcome or disrupt them.
Researchers have previously mimicked these features by creating materials with flat-topped microscopic pillars that cling to surfaces via van der Waals interactions. A new take on adhesives inspired by sticky gecko feet has led to soft, stretchy silicone patches that conduct electricity and cling fast to skin, even when underwater. The material could be used as comfortable, low-cost, reusable electrocardiography (ECG) electrodes for heart monitoring. Today’s disposable silver-based ECG electrodes have rigid metal parts and use glues that can irritate the skin. They can come off when wet or from too much movement, limiting a user’s ability to shower or exercise during longer periods of monitoring.
The new material could also be “crucially important in next-generation skinlike technologies for wearable electronics,” says John A. Rogers, a materials science professor at the University of Illinois, Urbana-Champaign, who was not involved in the work. Rogers and others are developing conformable tattoolike sensors to monitor fitness and various health conditions. The new material could make such devices more durable while doubling as an electrode.
Finally, Ronald S. Fearing, an electrical engineering and computer science professor at the University of California, Berkeley, says that such low-cost, nontoxic, skin-compatible electrodes may “find applications in interfaces for prosthetic devices, or perhaps even for monitoring muscle performance while exercising.” And unlike present-day ECG electrodes, he says, “long-term wear could be an option.” The KAIST team hopes to create other gecko adhesive variations by adding materials other than carbon. “For example, fillers with functionalities such as thermal conductivity, magnetism, and luminosity are excellent candidates for realizing different types of multifunctional, self-adhesive platforms,” Jeon says.
If you want to read more about this new, go to references. Do not forget see the images below. Thank you! Stephanie
A scanning electron micrograph shows 15-µm-tall pillars made of a polydimethylsiloxane composite containing carbon nanotubes and graphene powder. The soft, stretchy material conducts electricity and sticks to various surfaces, including skin.
I remember growing up and learning all about solids, liquids and gases. When I get accepted in college I learned that exist other states or phases of matter. The books and the information on internet almost always says that “there are only 3 states of matter, solid liquid and gas”. But is important to know that that ones are “the three most well-known types of matter” or “the three types of matter we are most scientifically familiar with”
The most common types of changes in the phases of matter consists of changing its physical characteristics not chemical characteristics .The best way to think of a phase changing the physical nature of a substance is with the common example of water, ice, and steam. They can occupy nearly the same region of space, and be in completely different phases. Consider a glass of ice water. The ice is in a solid phase, the water is in the liquid phase, and the humid air consisting of the evaporating gas is in another phase. While chemically they are the same, what makes them in different phases is that they are physically distinct from each other.
Most types of matter can transition into these physically different phases based on the amount of heat present. For instance, everyone knows that if you add heat to a solid it will usually transition into a liquid at least to most part of the matter. If you continue adding heat, the material will transition into a gas.
At least there are 13 different states of the matter. That number approximately quadruples the number of the basic sates that we all know. Is very important to know it because we can contribute to our scientific education and correct our professor even email a lot of companies that produce the books that we have to buy. And at the same time we stop the myth of the three states that is continuing forward to next generations from child to professional adults.
Some examples of other states of the matter are:
1. Plasma: If you continue to add heat you will turn that gas into plasma. Plasma is an ionized gas, it means that the atoms that compose it have broken away from some of its electrons. Thus, the plasma is similar to gas but composed of anions and cations (ions with negative and positive charge respectively), separated from each other and in free state, so it is an excellent conductor. A clear example is the sun.
2. When you continue cooling a substance to almost absolute zero, you can get what is known as a Bose-Einstein condensate. Due to the need to keep substances at extremely low temperatures, these condensates have not been proven to occur naturally in our universe, although theoretically they could exist.
3. Other, even less known, phases of matter involve the substance’s magnetic characteristics. The most recent example was published in the journal “Nature” in December of 2012. Researchers at MIT were able to grow a crystal (a solid) that had magnetic characteristics of a liquid. While most magnetic solids have defined positive and negative areas within the substance, known as magnetic moments, this crystal’s specific magnetic moments fluctuated constantly without outside influence. Not only were they able to discover this new type of matter, but simultaneously they discovered something of a new type of magnetism!
4. Super-solid: This material is a solid in the sense that all of the atoms of helium (4) that compose it are frozen in a rigid crystalline film, similar to as are the atoms and molecules in a solid normal as ice. The difference is that, in this case, "frozen" does not mean "stationary". So, As the film helium-4 is so cold (just a tenth of a degree above absolute zero), begin to prevail the laws of quantum uncertainty. Indeed, helium atoms begin to behave as if they were solid and fluid simultaneously. In fact, in the right circumstances, a fraction of helium atoms begin to move through the film as a substance known as "super-fluid," a fluid that moves without any friction.
As technology advances, scientists use ever more sophisticated techniques that allow us to know more about the world we live.
See the videos below and share your opinion with me. If you want to read more about this topic see the references.
As always
I say:“Chemistry surprises you with the simplest
things that you used to do in life”.
Now, I am
going to ask you: Have you ever seen people adding salt to ice in an ice cream
maker? Have you ever traveled to countries where the snow is falling and in the
next day people sprinkle salt on icy roads? The reason
that people do this is not an alien behavior; they do because salt lowers the
temperature at which water freezes. So, the question is how chemistry explains
this? The temperature enough to make water harden into ice is 32 degrees
Fahrenheit or 0 degrees Celsius. But when you sprinkle salt on ice, salt which
is a compound called sodium chloride, interrupts the freezing process of the
water. Some of the ice will melt because the salt pulls some water away from
its crystal form (ice) and also mixes with the thin layer of water on top of
the ice. This creates more saltwater, which will melt more ice. The dissolved
salt will also prevent the melted ice (now water) from refreezing. Molecularly,
salt slows the action of water molecules trying to join together into crystals
to form ice or snow. Now, the temperature to form ice again is about -10°C. For
example: on a winter road, the salt allows the ice to melt when the ambient
temperature is below freezing. In other words, for the mixture of salt and ice
or salt and water, it has to be colder than 0° C or 32° F to freeze. The
depression of freezing point of water by salt is an example of the colligative
properties of solutions.
The
colligative properties are: freezing point depression, boiling point elevation,
osmotic pressure and vapor pressure lowering. To understand how these
properties work I am going to explain briefly the concept of solution. In general, a solution is a homogeneous mixture
composed of a solute and solvent. The solute is the minority component which in
this case is the salt and the solvent is the majority component which in this
case is the water. The colligative properties depend on the number of particles
(solute) that were dissolved in solution (that contain solvent). Basically, the
more salt (solute) is added to the same amount of water (solvent), the lower
its freezing point will be.
Let’s use
chemistry in our favor to can go out in winter without the snow covering us at
all.
I want to
know others chemistry tricks that you use to combat the snow? Let me know which
are yours and remember see the video and photo below. Also, if you want to read more about colligative properties go to the references.
Yes, I am sure that you read the title
twice because you cannot pronounce it in the first try. Now, you are smiling
because what I said before is true. Do not worry I had to pronounce it almost
25 times to explain to my colleagues what that is? Let’s talk about luminescence in Chemistry or
best known as Chemiluminescence.
Everyone at once has seen glowsticks in a night club, fireflies or beautiful
jellyfishes glistening, but from where comes the illumination of those things
or species? The answer is simple, is because the Chemiluminescence. This is the
production of light from a chemical reaction. Two chemicals react to form an
intermediate in excited state (high energy), which is de-energized releasing
some of its energy as photons of light.
For example: Luminescent reactions of fireflies use ATP (adenosine
triphosphate) as a source of energy. The structure of molecules that produce
the light in fireflies varies from species to species, but they are generically
called luciferins. When fireflies glow, the luciferin is oxidized to produce an
excited complex, which falls back to the ground state, releasing a photon of
light. That light is what we see at night into the woods.
Fluorescent jellyfish are probably the epitome of chemiluminescence and
bioluminescence sophistication. They have a protein capable of receive high-energy
light (typically in the range of UV) called GFP (Green Fluorescence Protein)
that emits fluorescence in the range of green light (Although biotechnological
modifications have gotten proteins that emit virtually the entire visible
spectrum). Jellyfish are not nearly the only bioluminescence’s marine life, it
is believed that more than 90% of animal species average and abyssal ocean
portion emit some kind of bioluminescence. Also, there have been a series of
experiments investigating aequorin, a protein found in certain jellyfishes,
which produces blue light in the presence of calcium and therefore can be used
in molecular biology to measure calcium levels in cells.
Other way to see chemiluminescence… I think that everyone in a particular
moment has seen Action or Police movies which have scenes where a forensic
scientist investigates if in a zone there is blood present. And he or she does
it using an apparatus with light that show in seconds the blood stains.
Basically, in real life forensic scientists use reactions of luminol to detect
blood at the crime scene. A mixture of luminol in a dilute solution of hydrogen
peroxide is applied in the area where they suspect that is the blood. The iron
in the hemoglobin of blood accelerates the reaction and when the room is dark
and if blood is present, a blue glow, lasting 30 seconds is observed. Forensic
investigators can record the glow by using photographic film, which can be used
as evidence in court of blood in the scene.
Some scientists have proposed other ideas for utilizing chemiluminescence
in the future; from detect important ions in biological processes to have fluorescent
fishes as decoration. What other alternatives you think is useful for us, based
in this natural phenomenon and the concept of chemiluminescence?
As I said before my
purpose with this blog is not only share information that you cannot understand
or you do not like it or bores you. I want to catch your attention with chemistry;
science is not boring at all. Everyone in a moment dreams to have super powers
or abilities to do magic. Now, I have to tell you: that dream IS POSSIBLE WITH
CHEMISTRY!!
Chemists use reactions to produce different compounds. The majority of
magic chemistries are related to mix the correct things to have the most surprising
products. There is a many types of chemical reactions
that chemists do but the most used to magic chemistries are: oxidation-reduction,
combustion, synthesis, decomposition, substitution
or single replacement or metathesis. Doing these reactions
correctly we can produce: invisible inks, substances that change mysteriously
of color, water that muddies blowing air, an egg fry without oil and heat,
lemonade that turns into wine, white sugar becomes in black coal. It looks like
magic, but it is the product of chemistry and its reactions. And that is why I
call it magic chemistries.
You can use chemistry
in your favor to surprise other persons during a magic show or to have fun with
your family or friends or use it in science projects to catch the attention of
your public.
Below are the
scientific or chemical concepts behind two chemical tricks that you can do
carefully and with the consent of your parents:
1)Set money on fire and watch it burn out without damaging
the bill.
A combustion reaction occurs between alcohol and oxygen, producing heat
and light (energy) and carbon dioxide and water.
C2H5OH + 4 O2 -> 2 CO2 + 3 H2O + energy
When the bill is soaked an alcohol-water solution, the alcohol has a
high vapor pressure and is mainly on the outside of the material (a bill is
more like fabric than paper, which is nice, if you've ever accidentally washed
one). When the bill is lit, the alcohol is what actually burns. The temperature
at which the alcohol burns is not high enough to evaporate the water, which has
a high specific heat, so the bill remains wet and isn't able to catch fire on
its own. After the alcohol has burned, the flame goes out, leaving a slightly
damp dollar bill.
Materials: dollar bill, tongs, a lighter, salt, solution of
50% alcohol and 50% water (you can mix 95% alcohol with water in a 1:1 ratio,
if desired)
Procedure:
1.Prepare the alcohol and water solution. You can mix 50 ml of water with
50 ml of 95-100% alcohol.
2.Add a pinch salt or other colorant to the alcohol/water solution, to
help produce a visible flame.
3.Soak a dollar bill in the alcohol/water solution so that it is
thoroughly wet.
4.Use tongs to pick up the bill. Allow any excess liquid to drain. Move
the damp bill away from the alcohol-water solution.
5.Light the bill on fire and allow it to burn until the flame goes out.
2)Smoking fingers.
Phosphorus is a chemical element that can take several forms, called allotropes. The type of phosphorus in the striker of match
boxes is red phosphorus. When you burn the striker, the phosphorus is vaporized
and condenses into a solid onto the cool metal surface. This is white
phosphorus. The element has not changed identify just the structural
arrangement of the atoms. Rubbing your fingers together produces enough heat
from friction to vaporize the phosphorus into what appears to be smoke.
White phosphorus readily reacts with oxygen in air
to form a flammable compound. Because of this, one of the earliest uses of the
purified element was to make matches. The early phosphorus-based matches were dangerous, containing enough phosphorus
to poison a person. Modern matches are called "safety" matches
because they don't use highly toxic chemicals. The smoking fingers trick used
to be a popular school science demonstration. It is not performed much anymore
because of concerns about the risk from the phosphorus, but if you do the trick
infrequently, the dose of phosphorus is small. You can lessen the exposure by
wearing thin, disposable gloves and taking care not to breathe the vapor.
Materials: matchbox of safety matches, cold water faucet or
chilled pan, scissors, lighter
Procedure:
1.Cut out the striker portion of a matchbox from a box ofsafety
matches.
Trim off any paper around the striker.
2.Fold the striker in half, striker-sides facing each other.
3.Set the folded striker on top of the running cold water faucet or a
refrigerated metal pan.
4.Use a lighter to set fire to the
striker. Ignite both ends. Then run the lighter along the length of the folded
striker. It won't burn to ash, which is fine.
5.Discard the burned striker.
6.You will see a brown residue that has been deposited along the top of
the faucet or metal pan. Run your fingertip along the residue to pick it up.
Never is too late to make happy other persons, let’s make happy them
with chemistry. I invite you to read more of magic chemistries in the
references and see the videos below.
