According to the American Chemical Society, hands-on activities significantly enhance learning at all levels of science education. The American Chemical Society, or ACS, is the world’s largest association of individual chemical scientists and engineers, and its newest science education policies communicate the importance of hands-on learning in the science lab. ACS education programs begin pre-kindergarten and extend through undergraduate and graduate studies.
Hands-on activities are the basis for the laboratory portion of any science class and are essential for learning chemistry. A student enrolled in a hands-on chemistry course directly experiences laboratory chemicals, chemical properties and reactions as well as gaining familiarity with laboratory equipment and apparatus. There is simply no substitute for the real-life experience of hands-on training.
One good example demonstrating the superiority of hands-on learning over simulation or lecture is teaching a child to ride a bicycle. Putting a child on a bike and giving her a push teaches her much more in one minute than she could gain by watching videos of other children on bicycles or listening to a lecture on physics. Hands-on learning allows for deeper comprehension of scientific principles, and it benefits the American Chemical Society and the rest of the United States to campaign for a return to this inclusive style of education.
ACS has good reason to promote hands-on learning. A 1982 meta-analysis of 15 years of research including 57 studies of 13,000 students showed that students who participated in hands-on education scored 20 percent better than did students using traditional or textbook approaches. The students engaged in hands-on learning demonstrated gains in creativity, attitude, perception and logic. The National Assessment of Educational Progress noted that teachers who incorporated hands-on activities into the curriculum at least once a week out-performed their peers by more than 40 percent of a grade level in science.
No Child Left Behind act, or NCLB, appears to have had an unintended negative impact on hands-on learning, particularly for children at the elementary and middle school ages. Science is not a federally mandated assessment, so teachers and administrators instead focused on subjects compliant with NCLB assessments such as reading and math. Pupils who were students during the height of NCLB continue to struggle with this deficit well into their post-secondary education unless given an opportunity to catch up with adequate hands-on training in the laboratory. For many, this chance does not occur until high school or beyond, if at all.
Undergraduate and graduate institutions must offer hands-on opportunities in the laboratory to ensure graduates are able to meet and overcome the challenges of modern chemistry. Some of these advanced students will rely on these skills to solve real-world problems in the workplace while others return to the classroom to teach others. ACS challenges teachers to reach new goals of excellence and advocates certain measures to help educators achieve superiority, including requiring teachers to take undergraduate courses to ensure they are prepared to teach coursework and enhancing funding at all levels so that science teachers have access programs that allow them to expand and update their science knowledge base. ACS also encourages teachers and school systems to use technology to reach students with different learning styles. The ACS is also dedicated to improving the work conditions of science teachers, reduce attrition and improve safety in the classroom laboratory.
Some educators are tempted to take advantage of the shortcuts modern technology has to offer but teachers should choose wisely. Computer simulations are flashy and inexpensive but are not an adequate substitution for hands-on activities, even at the collegiate level. Educators must use computer simulation as a supplement to, not as a replacement for, hands-on learning. While intellectual curiosity should be piqued with internet searches, guided by lectures and accelerated with computer simulation and video, hands-on learning is still one of the most effective ways to instill confidence in knowledge and increased comfort with using laboratory and technical equipment.
ACS recognizes the special need for new assessment equipment at the undergraduate level. This equipment should assess a student’s understanding of science and the use of methods of science to give the instructor a fuller appreciation of the student’s grasp of science, not just his ability to recite scientific facts. Giving students access to a shared diode-array visible or UV-vis spectrometer to perform absorption, emission, fluorescence and reflectance experiments has so much more impact than just describing.
The American Chemical Society emphasizes the importance of a hands-on, inquiry-based approach to science to not only help students gain knowledge and understanding of scientific principles but also to teach students how scientists explore and make sense of the natural world. Hands-on learning teaches students to learn with the same tools used by professional scientists. It teaches them to think like scientists by creating hypotheses, making observations and performing inquiries. Students improve skill proficiency in scientific processes, such as laboratory work, graphing results and interpreting data.
Hands-on learning has been around since the days of Aristotle, who said, “What we have to learn to do, we learn by doing.” Hands-on learning enhances the student’s ability to test, sense, apply and learn. This type of learning involves and improves upon the art of questioning. Use hands-on, state of the art analytical instrumentation to revolutionize the way your students learn chemistry and science in your classroom laboratory.
“I hear and I forget, I see and I remember. I do and I understand”
Chinese proverb
"In the Beginning, There Was a Dog Kidney"
Friedrich Wöhler (1800-1882), German chemist. A student of Leopold Gmelin at Heidelberg and of the great Berzelius at Stockholm, Wöhler held teaching positions at Berlin and Cassel before accepting the chair in chemistry at Göttingen in 1836, where he remained for the rest of his life. An eclectic chemist, he is best known in the field of organic chemistry for his collaborative work with Liebig on the isomerism of the fulminate and cyanate radicals (1823) and on the chemistry of the benzoyl radical (1832), and for his synthesis of urea from ammonium cyanate, (1828) which was later interpreted as a decisive blow against the doctrine of vitalism. In the field of inorganic chemistry, he is best known for his isolation of the elements aluminum (1827) and beryllium (1828) and, in the field of chemical education, for the many 19th-century American chemists who came to study in his laboratory.
Courtesy of Professor William Jensen, Oesper Chair of the History of Chemistry and Chemical Education, University of Cincinnati
“Why do I have to learn junk I’ll never use in real life?” is arguably the most harrowing question to ever echo in a science or math classroom. For generations, an education in science, engineering or math has been mostly reserved for only those very bright students intending to pursue an advanced degree in one of those disciplines. Most of these students were white males, with strong social stigmas preventing females or students in minority groups from participating. Students who wanted to work in other professions or stay at home to raise kids often avoided science and math classes, thinking a working knowledge of these subjects unnecessary for a workaday life. Today’s fierce global economic climate does not allow modern student to cherry-pick skills to take into the workplace – even the most rudimentary jobs require a certain amount of technical sophistication and understanding of STEM subjects. While most students will not eventually work in a STEM field, they will enjoy life-long benefits from their experiences studying in a STEM-rich environment.
National Economy
A workforce well-educated in science, technology, engineering and math, or STEM, skills is now an absolute necessity to keep the United States in a competitive position in today’s global economy. According to a 2009 assessment of 15-year olds, the United States pulled a below-average ranking of 32nd in mathematics and an average rank of 23rd in science. These dismal statistics worry economists, industry leaders and politicians who recognize the power innovations science and technology has on the nation’s positions in the global markets. Knowledge is the engine that drives that innovation. Our nation needs an innovative strategy to its technical strength enough to compete in today’s global economy.
Improved Learning
One of the most obvious and innovative national strategies is to put STEM technology directly into the hands of high school students. STEM education transforms a teacher-centric classroom into a laboratory where curiosity and innovation propel discovery and learning. Cutting-edge STEM education tools replace dusty static textbooks with real-life technology. Lectures and memorization are swapped with curiosity and discovery, a more natural and long-lasting form of learning. The faces of students in an interactive STEM laboratory setting brighten as natural curiosity and inquisitiveness reawaken and reinvigorate their imaginations. The student shakes off her role as a passive learner and jumps right into the business of innovative thinking and learning. This type of exploratory thinking encourages valuable problem-solving and discovery skills students can use later in life, whether they plan to further their STEM education, go directly into the workforce or even stay at home and raise children.
Critical Thinking
Classes in STEM studies enhance critical thinking skills and require students to actively engage in a situation in order to find the solution. Students develop the same problem-solving skills in the secondary and post-secondary classroom as they will eventually use in the workplace. A savvy educator puts current technology into these students’ hands so they grow comfortable using these tools. Youngsters build STEM-specific proficiency along with critical thinking skills and familiarity with equipment as they go through secondary and post-secondary school or directly into the job market.
Increase Interest in STEM
Education in STEM studies during high school promotes interest in pursuing a post-secondary STEM degree. In a recent survey, four out of five STEM college students say they decided to study STEM while still in high school; more than half say that a specific class or a teacher, rather than a family member, got them interested in STEM subjects. This is especially true for women, with 68 percent of female students citing a teacher or a class as being the main motivation behind their decision to study STEM. Unfortunately, only one in five college STEM students say that elementary and high school adequately prepared them for college STEM courses. These students said it would have been helpful to take more STEM courses and for these courses to be more challenging.
Improved Collegiate Performance
The universities teaching advanced STEM courses would agree. One of the largest problems post-secondary institutions face is under-prepared freshmen. Universities and colleges yearn for entrants who are better educated in STEM subjects. Students entering STEM studies are woefully underprepared for collegiate courses and many students drop out before earning a degree.
Better Pay
Post-secondary STEM education results in better pay, even for workers who wind up in non-STEM positions. A person with a STEM degree will earn 13 percent more for the same job as another person without such credentials. This is especially true for women and minorities in STEM fields. While there is a gender and race gap associated with most other professions, women in STEM jobs make almost as much as their male counterparts.
The STEM skills learned in high school will serve a student well, even if she does not pursue a college degree or work in a STEM field. Even jobs in a big box store or fast food chain requires the use of hand-held electronic devices or scanners. Only repetitive, manual labor tasks do not require at least a fundamental education and the need for workers to perform this type of work has declined rapidly since the 1960s. Technology and robotics have replaced these workers with industrial machines. Today’s employers require interactive workers able to perform non-routine tasks based on a sound decision-making.
A secondary education rich in STEM studies benefits all students, whether they intend to pursue an advanced degree in the sciences or just work at the local discount store. STEM studies help students develop critical thinking skills, familiarize future workers with the equipment they will someday use and spark an interest in STEM fields. Improving secondary STEM education will improve our national workforce and enhance the way American workers do business.Discover all the learning solutions you can incorporate into your STEM laboratory.
Sparking a student’s interest in science, technology, engineering or math can launch her on a new career in the highly-lucrative and rapidly-expanding opportunities in STEM fields. Great pay, interesting work, job security and good working conditions are the norm for those holding a STEM degree or working in a STEM field, such as computer and information technology, engineering or life science. STEM fields are closing the gender gap, encouraging more women to reap the benefits of an education in science and technology. Solid STEM training benefits the workers of today and tomorrow.
Good Pay
Whether you earned a degree in a STEM field or you work in a STEM field without holding a diploma, STEM increases your average wages. A STEM worker with a bachelor’s degree will earn on average $7 more per hour than another person with the same credentials in a non-STEM occupation. Just holding a degree in a STEM field will increase wages. A person with a STEM degree makes 13 percent more doing the same job as a person without such an education. Those who study STEM or gain a degree in a STEM field have higher wages, even if they don’t ultimately work in a STEM field.
To put it in hard numbers, the Bureau of Labor Statistics, or BLS, reports the average annual wage for all STEM occupations was $77,880 in May of 2009. Natural science managers were the highest paid STEM workers, followed by engineering and computer science managers. These highest-paid workers held mean wages in excess of $100,000 or more.
Interesting Work
Working in a STEM job is exciting. All the cool things we love today are the result of the innovating and creative thinking of countless STEM workers, including our phones, computers and video games, live-saving medicines and other technical miracles. Whether a STEM worker uses her skills to bring a rare species of animal back from the brink of extinction or to design the automobile of tomorrow, work in a STEM field will always be challenging and highly rewarding.
Lower Unemployment
Workers in STEM jobs face a lower risk for unemployment than laborers in other fields. In 2010, unemployment rates among non-STEM workers were almost 10 percent, compared to only 5.3 percent unemployment among STEM workers. It is possible that this lower unemployment rate is due to the higher level of education among STEM workers; solid education, especially in STEM fields, reduces unemployment.
Increased Opportunities
The topic of STEM jobs and the education to get those lucrative jobs has never been hotter. The BLS projects STEM job growth to have grown 22 percent between the years of 2004 and 2014. Computer specialist occupations are expected to have grown much faster than average. Despite a sluggish national and global economy, STEM jobs continue to enjoy expanding opportunities for well-educated workers.
Decreased Gender Gap
There is a smaller economic gender gap in STEM jobs than in other professions, with women earning nearly the same income as men for performing a STEM job. Women who work in STEM fields make on average 33 percent more than women who work in non-STEM jobs. Many women with a STEM degree work in education or healthcare rather than in a STEM field.
Good Working Conditions
STEM jobs are usually performed inside air-conditioned offices or laboratories in technical parks located in nice sections of the country, such as southern California or Boulder, Colorado. Most of these jobs are quite safe, extremely exciting and always challenging. STEM workers typically share clean, quiet environments with other well-educated, like-minded professionals.
Before a worker enters the profitable and rewarding STEM field, he needs a solid STEM education. Early and secondary education is the key, whether a student plans to study STEM or enter a STEM field directly out of high school. Introducing students to science, technology, engineering and math at an early age can foster a passion that puts future workers on the right path, rich in financial and professional rewards.
http://educationupdate.com/archives/2011/NOV/HTML/col-stemjobs.html
http://www.bls.gov/opub/ooq/2007/spring/art04.pdf
http://www.bls.gov/opub/mlr/2011/05/art1full.pdf
http://www.esa.doc.gov/sites/default/files/reports/documents/womeninstemagaptoinnovation8311.pdf
"Annalen"
Justus von Liebig (1803-1873) Professor at Giessen (1824-1852) and Munich (1852-1873), Liebig's teaching laboratory at Giessen served as the model for the advanced training of chemists in the first half of the 19th century, including many foreign students from Great Britain and the United States, and, through his editorship (starting in 1832) of the journal, Annalen der Chemie und der Pharmacie (which is still published under the name of Liebig's Annalen), he exercised enormous influence on the early development of organic chemistry, agricultural chemistry, and physiology. He perfected organic combustion analysis (1837) and the counter-current laboratory condenser (1843), and, in collaboration with his close friend, Friedrich Wöhler, did pioneering work on the isomerism of fulminates (1823-1826) and the reactivity of the benzoyl radical (1832).
Courtesy of Professor William Jensen, Oesper Chair of the History of Chemistry and Chemical Education, University of Cincinnati
Carl Sagan once said, “It’s suicidal to create a society that depends on science and technology in which no one knows anything about science and technology.”
The United States is slipping behind other countries in awarding postsecondary STEM degrees. Between 1998 and 2006, the total number of STEM degrees grew by 23 percent in the United States. During this same period, Poland increased its number of STEM degrees by 144 percent and Taiwan boasted a 178 percent increase. China’s number of postsecondary STEM degrees exploded by a stunning 200 percent. In 2006, China awarded nearly double the number of postsecondary STEM degrees gained in the United States. The USA needs more STEM degrees if it hopes to compete in tomorrow’s global economy.
More STEM degrees mean more STEM jobs. Increasing the number of jobs in STEM fields is critical to the economic prosperity of both individuals and communities. Generally speaking, STEM jobs are some of the highest paying positions, with wages significantly above the US average. STEM jobs represent one of the fastest-growing segments of the job market, both in the United States and globally. Between 2008 and 2018, the number of STEM jobs is expected to have grown by 17 percent.
STEM occupations are associated with lower unemployment rates when compared to other professions. Students who graduate with a STEM degree but pursue jobs in non-STEM fields also make more money than those with degrees in other fields. Cities across the nation try to attract STEM professionals because civic leaders understand that the high pay and economic stability associated with STEM jobs benefits the economic and social fabric of the community.
The main pathway to a lucrative career in STEM fields is through postsecondary education. Getting bright minds into postsecondary programs poses a two-fold challenge to secondary educators – sparking interest in pursuing further education in STEM studies and properly preparing students to engage in higher learning. In most K–12 systems today, math and science subjects seem to have little to do with the real world. Students often ask, “When will I ever use this knowledge?” Students just don’t seem interested in STEM and educational institutions fail those few students leaning towards a STEM degree.
The National Governors Association explored this challenge in the December 2011 updated version of Building a Science, Technology, Engineering and Math Education Agenda. This committee examined the goals of the STEM agenda and outlined why this agenda is so important to the states and to the nation. They identified weak links in the system and outlined strategies to implement state-wide STEM agendas in ways that excite students about STEM studies and careers while giving them the tools to succeed in gaining a degree and securing a job.
The STEM agenda has two basic goals: expand the number of students entering postsecondary STEM studies and increase STEM proficiency in the general student population. The first goal improves the technical capabilities of the nation’s workforce while the second goal helps students implement concepts and problem-solving strategies gained through STEM studies into their everyday lives.
Proficiency in STEM facts, principles and techniques are just as beneficial to future employees of big-box stores as they are to the physicians and engineers of tomorrow. Integrating STEM concepts and hands-on learning into the regular curriculum will help the general student population hone critical thinking skills to recognize, evaluate and solve problems not related to science, technology, engineering or mathematics.
This study identified five areas that states are trying to improve upon in an effort to increase the number of interested students qualified to pursue postsecondary STEM studies. Inconsistent state standards, a shortfall of qualified instructors and failure to motivate student interest all prevent students from pursuing postsecondary studies in STEM. This study also suggests that students are not prepared for postsecondary STEM study because they lack hands-on learning and experience with laboratory equipment. Worse yet, many current postsecondary STEM studies do not properly prepare students to work in STEM fields.
Fortunately, the report by the National Governors Association contains solid research that provides direction to increasing the presence of STEM tools in your learning laboratory in a way that propels your students into postsecondary studies and high paying STEM jobs. Building a Science, Technology, Engineering and Math Education Agenda says that several studies correlate strong preparation in high school with improved STEM degree completion rates. Furthermore, certain high school instructional practices seem to be more effective than others, including doing hands-on experiments in science. Encouraging high school students to form workgroups also improves postsecondary STEM outcomes.
Use informal learning to help students make the connection between STEM classes and real-world applications. Field trips to museums, science centers and other public and private institutions showcase job opportunities for those with degrees in STEM fields. Many of these institutions provide hands-on activities using the same equipment professionals employ. The connections between STEM classes and real-world applications are reinforced when your students can then use these same pieces of equipment in their own classroom laboratories.
The National Governors Association notes that a “student’s ability to enter and complete a STEM postsecondary degree or credential is often jeopardized because the pupil did not take sufficiently challenging courses in high school or spend enough time practicing STEM skills in hands-on activities.” Hands-on learning chemistry labs improve a student’s experience in secondary school, giving her confidence to succeed in postsecondary STEM studies or in an entry-level non-STEM career.
Our nation’s security and economic stability rest in the capable hands of exceptional educators just like you. It is up to STEM educators to expand the knowledge of science and technology not only in collegiate hopefuls but in the student population as a whole. Improve your students’ chances of success competing in a global economy by training them the same chemistry laboratory equipment that universities and professionals use.
Science and technology bond together like carbon and hydrogen. One field benefits the other- scientific discoveries advance technological applications which then return more sophisticated research tools to the scientific community. Many of your chemistry students will graduate into a world that integrates science and technology into a singular platform that utilizes electronic data collection technology, a safer and more efficient mode of gathering and managing information. Give your freshman chemistry students the technological edge they need to facilitate learning while simultaneously freeing yourself from expensive hardware upgrades, viruses and archaic forms of monitoring student progress in your freshman chemistry lab.
When you switch to electronic data collection technology, you’ll immediately notice how much more available space you have in your general chemistry lab. In the typical, old-fashioned general chemistry lab, each student shared bench space with their own large, cumbersome PC. These PCs are at increased risk for virus infection, costly hardware and software upgrades and usually need to be replaced every three to four years. The MeasureNet MCAN, or Multifunctional Chemical Analysis Network, replaces up to 15 individual PCs with a single PC that is used by the instructor to monitor student activity and manage their data files, locally or on the cloud.
Student workstations integrate with a wide variety of probes and other chemistry laboratory apparatus that enable your chemistry lab students to accurately perform hands-on experiments in general chemistry, environmental chemistry, STEM and biochemistry labs. These hands-on lab exercises are critical for the students’ development of basic chemistry concepts.
Chances are good that students in your general chemistry lab are already technologically advanced and have used electronic data collection technology in high school. They are also quite accustomed to cloud computing from using products like Google Docs and Dropbox, where both software and files are saved online rather than on a personal computer. MeasureNet’s MCAN technology merges electronic data collection and cloud computing capabilities together. MCAN allows your student to measure and collect high resolution data in the lab and store it on the cloud for later analysis and lab report generation. Students, especially science students, will be excited to use the advanced technology MeasureNet MCAN offers. MeasureNet MCAN technology takes your students to the next level, giving your students the edge they need when whether they go on to industry or pursue advanced degrees in science.
Cloud computing also helps you monitor your chemistry lab students from the instructors PC to be sure they are conducting the experiment, collecting data and analyzing information properly. You can also monitor live data collection experiments remotely. Using the internet you can connect to MeasureNet MCAN workstations from outside the chemistry lab using a computer, tablet or smart phone.
MCAN electronic data collection technology can easily be in integrated into your current chemistry lab curriculum and can be adapted to fit a variety of teaching styles.
- POGIL
- STEM
- Self Directed
- Verification-style
- Inquiry-based Chemistry Labs
- Hands-on learning
You can easily integrate MeasureNet based experiments into your current lab curriculum. Here is a small sample of experiments that can be conducted with the MCAN technology.
- Gas Laws
- Colligative Properties
- Enthalpy of Reaction — Hess's Law
- Determination of the Heat of Neutralization of a Variety of Strong Acids and Bases
- Chemical Kinetics
- Determination of a Reaction Equalibrium Constant Using Absorption Spectroscopy
- pH and Buffer Solutions
- pH titrations and end-point determination using Drop Counter
- Identifying a Weak Unknown Acid
- Determination of the Molecular Weight of a Volatile Liquid Using the Ideal Gas Law
- Vapor Pressure and Heat of Vaporization
Using MeasureNet’s MCAN technology in your lab means you’ll spend less time working as a computer repair technician and more time teaching chemistry. The MeasureNet MCAN frees you from problems usually associated with PC-based systems. Virus removal and reimaging computers will be a thing of the past.
Get back to doing what you love – teaching chemistry to hungry minds – by replacing your old, worn out computers with intuitive space saving MCAN electronic data collection technology. Excite students in your general chemistry labs by using the same technically advanced instrumentation used by university research labs and real-world industry chemistry labs. Make your chemistry lab program exciting and technologically relevant to students by using electronic data collection technology in your labs.
The MCAN® Concept
The MeasureNet Multifunctional Chemical Analysis Network (MCAN® ) is an innovative analytical instrumentation eliminating a multitude of the obstacles that are associated with the PC-based lab systems. With the consolidation of student data acquisition workstations into a solitary network for each group of students, expensive hardware upgrades, computer viruses and the footprint of large equipment is eliminated.
The student workstations we provide interface with numerous kinds of probes as well as other apparatus that are utilized in chemistry laboratories. This allows for a broad range of general chemistry, physical chemistry and biochemistry lab experiments.
MeasureNet can be useful in a freshman chemistry lab or in advanced chemistry labs. Whether used in the freshman chemistry lab, biochemistry, STEM, or environmental chemistry laboratories, MeasureNet is an essential tool.
With MeasureNet, the student takes the measurements at their workstation and the results of those measurements can be stored and then monitored on a single central computer. This allows the instructor to follow student progress and data files. There is no need to contend with the multiple headaches that are associated with managing student lab data because MeasureNet can do it all for you.
Solutions in the Chemistry Lab with MeasureNet
- Less bench space due to energy efficient workstations with smaller foot prints.
- Securely Protected online data storage for students.
- Viruses and computer re-imaging are things of the past with MeasureNet.
- The collection of data electronically allows for more time being spent on the actual experiments.
- Eliminates the need to upgrade large numbers of computers every few years.
- The best quality, research grade chemistry probware is utilized to collect high-resolution data.
General Chemistry Lab Experiments Performed with MeasureNet
MeasureNet was designed to offer instructors considerable academic flexibility with its ability to support a wide range of experiments.
MeasureNet has the ability to support experiments for individual or collaborative student projects in a freshman chemistry lab or in an advanced lab.
The adoption of electronic data acquisition does not require the disposal of experiments that have been proven to build the students’ skills or enhance their understanding of imperative concepts. The longstanding experiments can very easily be integrated into curricula combined with the experiments appropriate for MeasureNet. Other experiments requiring conversion can be modified with the assistance of our curriculum specialists.
Title examples for Guided inquiry, Self-Directed, POGIL, Verification-style and STEM experiments utilizing MeasureNet are as follows:
- Specific Heat of a Metal
- Hot & Cold Packs- Dystan Medical Supply Company
- A Colligative Property of Solutions-Freezing Point
- Quality control at the GlassEX Company-Self-Directed
- Buffer & pH Solutions
- Proteins & Amino Acids
- Chemical Kinetics
- Gas Laws
- Voltaic Cells
- Substances Specific Heat
- Analysis of Metals Emissions
- Heat of Vaporization & Vapor Pressure
- Determining Chromium (VI) Concentrations using Absorption Spectroscopy
- Colligative Properties
- Determining the Cause of a Fish Kill Located in the Clark Fork of the Columbia River
- Identification of a Weak Unknown Acid
- Analysis of the Phosphorus in Cola
- Identification of an Unknown Metal-Self Directed
- Determining the Ka Value of a Weak Acid
- Determining the concentration of Acetic Acid in Vinegar
- Determining the Molecular Weight, with the use of the Ideal Gas Law, of a Volatile liquid
- Hess’ Law-Enthalpy of Reaction
- Analysis of the Phosphorus in Fertilizer
- Determining the Heat of Neutralization for Various Strong Bases & Acid
- Reaction Stoichiometry & Moles
- Determining a Reaction Equilibrium Constant with the Use of Absorption Spectroscopy
- Analysis of Emission of Aequeous Solutions from Group IA & IIA Metal Salts
Stanislao Cannizzaro (1826-1910) Professor at Alessandria (1851-1854), Genoa (1855-1859), Palermo (1860-1869) and Rome (1870-1910), Cannizzaro is best known for his discovery of the Cannizzaro reaction in organic chemistry for the conversion of aromatic aldehydes into the corresponding acids and alcohols, and his successful resolution of the atomic weight problem. Though Dalton had introduced the idea of extracting atomic weights from combining weights in 1803, he was unable to do this in a completely unambiguous fashion and, as a result, 50 years of chaos followed during which chemists used a variety of competing atomic and equivalent weight values. In 1858 Cannizzaro published a small pamphlet in which he reasserted Avogadro's earlier hypothesis (1811) that gas densities at equal pressures were directly proportional to molecular weights. Whereas Avogadro had attempted to extract atomic weights from the resulting molecular weights by using the stoichiometries of gas reactions - a procedure that could be applied only to a few elements - Cannizzaro showed how this same information could be extracted by using the gravimetric composition of an element's volatile compounds - a procedure that was virtually universal. With Cannizzaro's advance, chemists finally acquired a standard set of atomic weights and were able to determine unambiguous and universally accepted compositional formulas for their compounds.
Courtesy of Professor William Jensen, Oesper Chair of the History of Chemistry and Chemical Education, University of Cincinnati
Measurement of molecular fluorescence is an important analytical technique in chemical and biological sciences. The capacity of detecting very small fluorophore concentrations, or small changes in its concentration, combined with high specificity make this technique a very powerful analytical tool.
Kinetic methods for determining reaction rates are commonly used. While most experiments are designed to determine the order of a particular reaction in order to gain insight to the reaction mechanism, kinetic methods are also used for quantitative analysis. Determination of the initial reaction rate is one way of quantitatively analyzing a compound within a suitable reaction system.
The following experiment is designed to introduce students to both of these concepts, fluorescence and kinetics as analytical method. This combined technique has the advantage of increased analyte specificity over equilibrium-based fluorescence measurements. As only the compound that is reacting is causing a change in the measured fluorescence signal, steady-state interferences are largely eliminated.
Thiamine (vitamin B1) is essential for the metabolism of carbohydrates and normal function of he nervous and cardiovascular systems. Severe vitamin B1 deficiency will eventually lead to beriberi, characterized by abnormal functions of the muscular and nervous systems, as well as heart and brain abnormalities. Vitamin B1 occurs naturally in foods like whole grains, nuts, vegetables, pork, and liver.
Thiamine (TM), a non-fluorescent compound, has been found to be oxidized selectively by mercuric oxide (HgO) at a rate suitable for monitoring with standard fluorescence spectrometers.1 The oxidation product, thiochrome (TC), is fluorescent with a strong absorbance maximum at 367 nm and fluorescence emission at 444 nm. Deprotonation of TM yields a non-fluorescent tricyclic intermediate (CI), which is oxidized to TC as outlined in Scheme 1. Immediate oxidation of CI is essential to avoid the formation of several non-fluorescent productions.1 Thus, it is important to follow the sequential addition of reactants as outlined below... To view the complete experiment Click Here.