Microscale Chemistry: Experiments in Miniature Pdf, Epub, Ebook

MICROSCALE CHEMISTRY: EXPERIMENTS IN MINIATURE PDF, EPUB, EBOOK

A microscale study of gas diffusion Observe the diffusion of the gases ammonia and chlorine, and their relative rates as a function of molecular weight. Microscale chemistry experiments use small quantities of chemicals and simple equipment. When turning on the water supply, always start the water slowly and carefully to prevent hoses from coming loose and wetting the lab bench. All weighings must be made into a previously weighed " tared " container. Step 4. After bending the copper wire back up the side of the centrifuge tube so that the Craig tube is held securely inside it see 'B' below , the centrifuge tube is inverted see 'C' below. Science News. Method B - solvent lighter than water Recrystallizations Back to Index Recrystallizations can be carried out using a conical reaction vial and conventional vacuum filtration to collect the crystals on a small filter paper, or in a Craig tube , which is a device designed specifically for recrystallization of very small quantities of materials. Chemistry World. Back to Index Microscale experiments involve quantities on the order of mg at most, and it is thus important to be able to weigh solid substances to the nearest milligram. Microscale equipment can also provide insight into whether or not a reaction will be successful without wasting larger quantities of material. Create carbon dioxide from marble chips and acid, then test for its reaction with barium hydroxide by observing the carbonate precipitate. Learn how to carry out microscale experiments for greener chemistry teaching — and less washing up. Elias Kalogirou and Eleni Nicas introduce a selection of very small-scale chemistry experiments for school. Infrared Spectroscopy, by Jennifer Farmer. Commonly called "labs on a chip," microfluidic systems are used to study and analyze very small-scale chemical or biological New Titles. Further ideas are provided in the teacher notes. Depending on your choice of solvents, you may be directed to set up the apparatus in the fume hood. The cooled vapors condense and drip back down into the reaction vessel. Gas Chromatography Techniques. Make certain to have a place for the round bottom flask to sit, either supported by a clamp or a cork ring before adding in reagents. The glass is a made from borosilicate material, which resists themoexpansion and is often used for bakeware in the kitchen. With the clamp loosely connected to the stand, maneuver the ground glass joint of the condenser securely into the neck of the round bottom flask and with your other hand tighten the clamp to the stand. It is important that enough cotton is used to collect all the solid being filtered; however, the amount used should not be so large that the flow rate throught the pipet is significantly restricted. Sign in Register Search. Once crystallization is complete, a 3" piece of copper wire is wrapped around the barrel of the inner plug of the Craig tube see 'A' below , and a Centrifuge tube is placed over top of it. Well 2 1 drinking-straw tip of sodium bicarbonate 5 drops of hydrochloric acid solution. Unlike the precipitation reactions, this experiment does not use hypodermic needles, and so it is suitable for students from age Alternatively, the solid can be dissolved in the Craig tube and the liquid transferred to the test tube using a Pasteur pipet preheated with hot solvent. The mixture to be filtered is transferred to the filtering pipet with another Pasteur pipet. Glassware Joints. Open Access. The electrolyte ions migrate from the filter paper into the balls, where the deposit forms. The bath contains slightly more than 1 cm of sand - it is important to have enough to ensure good thermal contact with the reaction vial, but not so much that it is difficult to see the contents. EIROforum members:. Show health and safety information Please be aware that resources have been published on the website in the form that they were originally supplied. Because so little reagent is used in each hydrogel ball, the filled hypodermic syringes can be reused in the next chemistry lesson. If a condenser or internal thermometer is used, the distilling apparatus must be partially disassembled in order to do this. Hypodermic needles must be counted when given out and when given back, so that all are accounted for. This activity is provided by ASE and describes a novel way to conduct a number of chemistry experiments on a small scale with clearly visible results and needing a minimum of equipment. Microscale Reflux Setup. D The reaction has heated such that there is no noticeable liquid left in the reaction flask. Measuring an equilibrium constant on a microscale Use your microscale titration apparatus to determine the equilibrium constant for the reaction between silver I and iron II ions. Microscale Chemistry: Experiments in Miniature Writer

Microscale chemistry and green chemistry: complementary pedagogies. Journals Books Databases. Several reactions can be carried out on the same filter paper if gaps are left between the reaction spots. In Experiment 3, the students observe how acids react with carbonates. Acquiring a Melting Point. Question 2. Attach the cold water condenser with the proper pieces including seals. Ask for directions whenever you are unsure, do not guess. Findings from this study indicate that there were no significant attitude and motivation changes as a result of performing microscale experiments. Journal Reference : Daniel J. After the treatment, the same attitude and motivation questionnaire was administered to all the students with an additional 9 items regarding perceptions towards microscale chemistry experiments. To prepare the limewater saturated calcium hydroxide solution , fill a ml beaker one-third full with calcium hydroxide [Ca OH 2 ] and add distilled water up to the ml mark. Downloads Preview Download. Practical or laboratory classes were conducted every week for a duration of two and a half months. In Experiment 5, the students investigate the conductivity of distilled water, hydrochloric acid and sodium hydroxide solution. Vermaak, I. What do they do? For the past three years, however, we have been doing microscale chemistry experiments at our school — using one or two drops of each reagent. Round bottom flasks will not self-support since they have a round bottom, so using a cork ring is strongly recommended when preparing your reaction mixture to prevent your solvent from spilling on the bench. Historical Collection. ISSN From an educational point of view, chemistry without laboratory work was seen as a body of factual information and general laws which conveyed nothing of lasting power to the mind Layton, This study was conducted to answer the following questions: 1. In general, students have a positive view of microscale chemistry experiments. The glass is a made from borosilicate material, which resists themoexpansion and is often used for bakeware in the kitchen. Microscale chemistry benefits the environment and lab practices. Hold the condenser over the sink and disconnect the hose connected to the faucet first and allow the water to drain, invert the condenser and finally remove the last hose from the condenser while continually draining the water directly into the drain. In particular, he encourages the use of microscale experiments at school. Microscale Chemistry: Experiments in Miniature Reviews

For ideas, projects, methods, news and other resources, see the Scientix website. C To make sure no water leaks out. Magnetic Stir bars. The cooled vapors condense and drip back down into the reaction vessel. The role of laboratory in science teaching: neglected aspects of research. Back to Index Since one rarely works with volumes larger than mL, graduated cylinders are rarely used in microscale experiments. A phenomenon known as Braess's paradox has demonstrated -- in traffic patterns, electronics, springs -- that sometimes having more pathways to travel actually slows down traffic rather than speeds it up. They are available in different sizes, and can deliver accurate volumes of aqueous solutions from 0. Glassware Joints. Microscience kit. Eleni Nicas trained as a biologist and for the past six years has taught biology, chemistry and physics at middle school ages , currently at the 4th Junior High School of Pyrgos. Each part contain between 6 and 10 experiments and we have tried to use related compounds in these experiments. His findings indicated that a positive attitude change towards learning chemistry was associated with evidence of motivated behaviour, while a negative change was linked to less motivated behaviour. Turn the water off, and remove the cold water condenser and any attachments from the universal stand, without disconnecting the hoses. Boiling a liquid may cause a violent physical reaction in which parts of a liquid solution become superheated and vapor quickly discharges creating a bumping. If desired, the rate of filtration can be increased by genly applying pressure to the top of the pipet using a pipet bulb. Most commonly, the material is transferred to the filter by pouring, using a microspatula to help transfer the crystals from the vial to the filter. Taking a cue from a counterintuitive theory about traffic patterns, the scientists found that shortcuts aren't always the fastest way from point A to point B. Task Value Scale 2. Clean up a microscale oil spill and discuss the application of chemistry in tackling real-life environmental problems. A condenser is fitted on top of the conical vial. Redox reactions Carry out two redox reactions and observe and interpret the results. Laboratory Equipment for Reflux. However, findings from the survey conducted showed no significant difference in attitude and motivation before and after the treatment. In contrast, Madeira found that the interest and motivation of the students from Mozambican Junior Secondary Schools increased after using microchemistry kits.

Microscale Chemistry: Experiments in Miniature Read Online

Research in Science Education, 27 4 , Standard or Mini- Scale Reflux Setup. Image Credits. Pre and posttests were conducted before and after the treatment. However, his findings were limited to the number of experiments and students involved in his study. The steps involved are fundamentally the same as those performed in macroscale crystallizations with an Erlenmeyer flask and a Hirsch funnel:. Well 1 10 drops of lemon juice 2 drops of red cabbage indicator. Microscale chemistry: experiments in miniature focuses on the recent trend of developing smaller-scale experiments for use in the classroom. Microscale extraction of copper In association with Nuffield Foundation Reveal the relative positions of copper and hydrogen in the reactivity series. For quantities of materials in the 0. Collection of fractions is easiest with the ported Hickman head; the port is opened and the liquid in the well removed with a Pasteur pipet see 'C'. Because colourful compounds were used, the reactions were immediately visible and the products could be identified just from their colour. Each experiment takes place in a separate well of the packet. Precipitation reactions of lead compounds Identify which compounds would make good pigments by observing the colour changes of lead nitrate solutions when different anions are added. C To make sure no water leaks out. Recall, a closed system can never be heated. Set up the heating source underneath the reaction flask. This problem may be remedied by bending the tip of the pipet slightly in a flame. FIt the cold water condenser into the second clamp so that it holds it just underneath the water outlet. Experiments Rather than using normal, full-scale laboratory equipment, these experiments are carried out in a chewing-gum blister packet, from which the foil and the gum have been removed see image. In a recent study published in Nature, researchers from Saint Louis University along with colleagues from Northwestern University and Normandie Universite shared their discovery of a way to program built-in controls in a microfluidic network. The stir bar's motion is driven by the rotary action of a magnet, usually fixed within a hot plate. Displacement reactions of metals Examine the reactions between various metals and metal salt solutions. Issue They also suggested that more time should be devoted to practical work and perceived that chemistry practical work is relevant in daily life. The purpose of heating is to help promote reactions by providing the energy required to break and make bonds. This significant difference in their interest and motivation may be because their students have been exposed to less practical work in chemistry before the treatment whereas in the Malaysian context, the students have been used to traditional laboratory work in the lower secondary levels. The students were also asked to give open-ended comments in order to obtain their perceptions and feedback about microscale chemistry experiments. In the electrolysis of water experiment, the bubbles of evolved gas hydrogen at the cathode and oxygen at the anode were very visible figure 5. Laboratory Equipment for Reflux. Student perceptions towards the microscale chemistry experiments are presented in Table 7. Layton, D. The treatment of oil spills Clean up a microscale oil spill and discuss the application of chemistry in tackling real-life environmental problems. Although safety precautions are still necessary, the risk involved is lower with smaller volumes — and the students had no difficulties manipulating such small quantities. The students perceived that microscale experiments were easy to handle and they were very keen to do more experiments. Data for the test anxiety in Table 5 shows that responses for all items ranged between 3. It is a unique learning environment that is effective in helping students construct their knowledge, develop logical and inquiry- type skills and develop psychomotor skills. The kit uses a plastic microwell plate with two sizes of microwells. To draw the liquid into the pipet, expel the air from the pipet and then place the end of the pipet on the bottom of the tube, being careful not to trap any solid in the pipet. Observe and interpret the changes when drops of various anion solutions are added to drops of group 2 element cations. If desired, the rate of filtration can be increased by genly applying pressure to the top of the pipet using a pipet bulb. Is there any significant difference in student attitude towards chemistry laboratory work before and after doing microscale experiments? Hofstein, A. Vermaak, I. In Experiment 5, the students investigate the conductivity of distilled water, hydrochloric acid and sodium hydroxide solution. 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