Is Refractometry Useful In The Microscale Organic Chemistry Lab

Organic Chemistry I Chm 336 Lab 3

Samantha Truckly _____/30Experiment Title: Boiling Point, Refractive Index, and Introduction to Gas ChromatographyDate : February 13th, 2018Laboratory Partners: Selina and MackenzieGoals: To identify an organic compound using its boiling point and refractive index as well as using a gas chromatogram to find the mass percentage of a mixture. Procedure:D2: Determining the Boiling Point of an Unknown Liquid1. Obtain unknown liquid, boiling chip, craig tube, clamps, heat block, thermometer, and nomograph. Record unknown liquid number in lab notebook. 2. Add 0. 3-0. 5 mL of unknown and boiling chip to test tube. 3. Clamp tube in heat block and suspend thermometer so the end of the bulb is 0. 5 cm above the liquid. 4. Heat slowly. Once the temperature is stable, record the temperature in lab notebook. 5. Identify the unknown liquid and record in the lab notebook. 6. Calculate the percent error between the obtained boiling point and the actual boiling point. Record in notebook.

Digital Refractometers Universal Concentration Meters

By Angelo DePalma, Ph.D Partial Reprint Originally Published April 6th, 2011, for original seeLab Manager Refractometers are instruments that quantify and identify chemicals and materials based on their refractive index . A unique property related to the speed of light as it passes through a substance, RI is defined as the ratio of the speed of light in a vacuum relative to its speed in the test material.For example, the RI of pure water is 1.33, meaning that light passes through a vacuum 1.33 times faster than it does through water.Since light also changes direction as it passes from one medium to another, RI is conveniently measured as a function of this unique angle of refraction. Everyone is familiar with how a partially submerged stick seems to bendas it enters water. Refractometers quantify RI by measuring the angle formed by light as it leaves air and enters the test object.

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What to look for

Surface Plasmon Resonance And Localized Surface Plasmon Resonance

Surface plasmon resonance/localized surface plasmon resonance refer to the excitation of collective electron charge oscillations on planar metal surfaces or onto the surface of metallic nanoparticles by incident light. The oscillation leads to a wavelength-dependent reduction in the overall reflection, which presents an absorption peak in the reflection/scatter spectrum. As the SPR is very sensitive to the RI near the metal surface , it is widely used to develop RI sensors and biosensors . Unlike most other types of sensing schemes, metal plane/particle/nanohole arrays represent an indispensable part of the sensing system, which also offers unique opportunities for function appending and upgrading. A. Barik et al. utilized a gold nanohole array-based optofluidic device for label-free detection of analyte molecules, of which the nanohole array also generated gradient dielectrophoretic force to accumulate the measured biological analytes . Real-time detection was over 1000 times faster than the classic diffusion method for 1 pM analyte concentration. S. Kang et al. combined RI sensing with surface-enhanced Raman spectroscopy in silverâgold layered bimetallic plasmonic crystals to conduct quantitative and qualitative measurements simultaneously . D. Zhang et al. developed a unique nanoscale cup array coupling electrochemistry to LSPR spectroscopy measurement, offering a novel method by which to evaluate complex electrochemical reaction processes .

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Using The Abbe Refractometer

1. Make sure the unit is plugged in. Then turn the on off switch to ON. The light at the end of the moveable arm should come on.

2. Open the hinged sample prisms. NOT touching the prisms at all, place a few drops of your liquid on the lower prism. Then, swing the upper prism back over the lower one and gently close the prisms. Never touch the prisms with any hard object or youll scratch them.

3. Raise the light on the end of the moveable arm so that the light illuminates the upper prism. Get out your dime and, with permission of your instructor, tighten the light source swivel arm lock nut as it gets tired and lets the light drop.

Fig. 104 Your sample through the lens of the refractor.

4. Look in the eyepiece. Slowly, carefully, with very little force, turn the large scale and sample image adjust knob from one end of its rotation to the other. Do not FORCE!

5. You are looking for a split optical field of light and dark . This may not be very distinct. You may have to raise or lower the light source and scan the sample a few times.

6. If you see color fringing at the boundary between light and dark , slowly turn the compensating prism adjust until the colors are at a minimum. You may now have to go back and readjust the sample image knob a bit after you do this.

7. Press and hold the scale/sample field switch. The refractive index scale should appear . Read the uppermost scale, the refractive index, to four decimal places.

Fig. 105 A refractive index of l .4398.

Questions Astudent Measures The Refractive Index Of A

So in this question we have a thin converting lens of refractive index. New. This is equal to 1.5 and power has plus five diabetes. Okay. And when this lens is immersed in a liquid, it acts as a diverging lens.

So in this question we have a thin converting lens of refractive index. New. This is equal to 1. 5 and power has plus five diabetes. Okay. And when this lens is immersed in a liquid, it acts as a diverging lens. Diverging lens of focal length F equals 200 centimeters. So we have to determine the refractive index of the liquid. Okay, so we know that poverty it is equal to one by F. And one by F. From the formula it is equal to mutual minus Mulan new to buy a new one minus one and one by our one minus one by. Are you okay? So for the first situation this situation when power is five chapter or we can stay here. One by F is plus five plus five. This is equal to new to which is 1. 5 and we won which will be here so minus one and one by carbon minus one by our. Okay, okay. So this is can be written as also so we can right here that this will be equal to five, this is equal to 0. 5 after solving it and one by our one minus one by our. Okay, so suppose this is a very question number one for the second situation when the liquid medium is used.

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New Areas For Exploration: Volume Sensing

Currently, most RI sensors are developed based on near-field optics, which uses evanescent waves in the subwavelength region. Dramatically decayed evanescence has marked light-analyte interaction, indicating high sensitivity, but its spatial interaction is intrinsically limited by the attenuation characteristics of evanescent waves. On the other hand, some bio-analytes tend to measure 20â30 μm in diameter in this case, organisms deep inside the cells are outside of the evanescent field and cannot be measured accurately. For RI sensors working on evanescent waves, only the sample in contact with the sensing surface can be measured, which hinders the detection of naturally suspended samples. Furthermore, because the spatial measurement range is expanded from nearly 2D to 3D, volume sensing is a feasible way to increase light-analyte interaction. In volume sensing, the lightwave can completely permeate the targeted sample and detect every particle in the solutionânot only the sample attached to the sensing surface. Hence, this method is particularly useful for monolithic biological samples and analytes in low-concentration solutions, which is a rising research subject offering clear advantages in a host of applications.

Laboratory / Abbe Refractometer

Abbe Refractometer are highly reliable classic instrumentswhich measure Refractive Index. Compared with other types ofrefractometers, the Abbe refractometer are capable ofmeasuring liquid and solid samples such as plate glasses,plastic sheets, and other solid films. They have sapphireprisms and sealed optics. A computer interface is usuallya standard feature for printing and data download. Productivityfeatures include flow through modules and temperaturestabilization accessories. Therefore, this style of instrument cangive good accuracy on most sample types, not just sugar.

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Advanced Methods For Performance Enhancement

According to Equation , FOM can be optimized from two angles: sensitivity and quality factor. Improving sensitivity depends mainly on enhancing the light-analyte interaction however, strong light-analyte interaction also indicates intense absorption from solvent, where are often water or phosphate-buffered solution with certain concentration. Therefore, spatially accumulating or attracting interested particles to the area with the strongest light-analyte interaction via external field/force or a microfluidic sorting structure is an effective way to avoid the influence of solvent absorption. Furthermore, cascaded/hybrid structures, such as coupled resonator-induced transparence and Vernier effect , improve the Q factor and sensitivity synchronously and contribute to resolving the interaction-absorption dilemma.

Is Refractometry Useful In The Microscale Organic Chemistry Lab

Microscale and Macroscale Techniques in the Organic Laboratory by Pavia, Donald, Lampman, Gary, Kriz, George, Engel, Randall. Buy Microscale and Macroscale Techniques in the Organic Laboratory by Pavia, Donald, Lampman, Gary, Kriz, George, Engel, Randall online on Amazon.ae at best prices. Fast and free shipping free returns cash on delivery available on eligible purchase.

This book deals with the instrumentation and theory behind the many methods that are dealt with in an organic laboratory. The examples and the questions at the end of each chapter reflect the readings, which is a plus. But then again, if you are looking for a book that pushes you to think critically and outside the box, this book is not for you. This book is clear-cut and simple to understand and it does not ask you to exert your mental capacity in solving the questions. Overall, good find, good book, good price.

Video advice: 204 Refractometer

Is Refractometry Useful In The Microscale Organic Chemistry Get answers to: Is refractometry useful in the microscale organic chemistry A student measures the refractive index of an organic liquid. The value is 1.2821 at 18 degree C. What is the corrected refractive index? Is refractometry useful in the microscale organic chemistry lab? Explain. Do impurities raise or lower the refractive index of a liquid? Explain.

Answer to Solved Is refractometry useful in the microscale organic.

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Richard A Paselk Curator

Refractometry has been a major tool in the chemical laboratoryto determine concentrations of solutions and as an aid in identifyingunknown substances since the late nineteenth century. In principleevery substance has a unique refractive index, n, whichcould be used in its identification. However, in reality refractiveindex is of limited value since the values of n for millionsof organic compounds are in the range of 1.25 – 1.8, and no instrumenthas the ability to parse this range to this degree.1

Refractometry Definition Measuring Refractive Index

Refractive Index Measurement or Refractometry is the method of measuring substances refractive index and assess their composition or purity. Refractometry is a technique that measures how light is refracted when it passes through a given substance. Snells Law which is also known as The Law of Refraction describes the formula behind the refraction:

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Determination Of Alcohol Content In Alcoholic Beverages Using 45mhz Benchtop Nmr Spectrometer

Meden F. Isaac-LamAcademic Editor: Received

Abstract

Alcohol or ethanol is considered the most widely used recreational drug worldwide, and its production, consumption, and sale are strictly regulated by laws. Alcohol content of alcoholic beverages is about 350% v/v. Analytical methods to determine the alcohol content must be reliable, precise, and accurate. In this study, the amount of ethanol in several alcoholic beverages was determined using a 45MHz low-field benchtop NMR spectrometer. Internal standard and standard addition analytical methods were utilized to quantify ethanol. For both methods, acetic acid or acetonitrile was used as internal standard to quantify alcohol content by using the peak area corresponding to the methyl peaks of ethanol, acetic acid, or acetonitrile. Results showed that internal standard method gave values of percent alcohol that are in close agreement with the indicated label as confirmed by running the samples in a 400MHz high-field NMR spectrometer using acetic acid as internal standard. This study demonstrates the utility of a benchtop NMR spectrometer that can provide an alternative technique to analyze percent alcohol in alcoholic products.

1. Introduction

2. Materials and Method

2.1. Materials

2.2. Sample Preparation

2.3. 1H NMR Spectroscopy

3. Results and Discussion

4. Conclusion

Competing Interests

Laboratory Techniques In Organic Chemistry Fourth Edition

Request a sample or learn about ordering options for Laboratory Techniques in Organic Chemistry, 4th Edition by Jerry Mohrig from the Macmillan Learning Instructor Catalog.

Laboratory Techniques in Organic Chemistry is the most comprehensive and detailed presentation of the lab techniques organic chemistry students need to know. Compatible with any organic chemistry lab manual or set of experiments, it combines specific instructions for three different kinds o. . .

• Jerry R. Mohrig

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Parameters For Sensor Characterization

Sensitivity, defined as the magnitude in shift of the characteristic wavelength versus the change in a sampleâs RI, is a key parameter describing RI sensor performance. However, for measurement response down to the sensorâs detection limit , many factors should be considered: the shape of the resonant peak, noise sources, and signal intensity, among others. According to X. D. Fanâs detailed analysis, a sensor with lower sensitivity but a sharper resonance peak has higher resolution . Thus, to accurately describe sensor performance, a comprehensive evaluation that includes sensitivity and quality factors is crucial. Several novel parameters, such as figure of merit or detectivity , have been proposed in some papers. FOM is defined as the ratio of sensitivity to full wave at half maximum as Equation , which can take both of the sensitivity and Q value into consideration, thus the performance of the sensor can be characterized accurately by using a single parameter.

Carl Zeiss Abbe Refractometers

The Carl Zeiss company was the originator and home of the Abberefractometer for much of its history. Ernst Abbe published hisNeue Apparate…. 2 in which he discussedthe theory and described instruments he had developed for themeasurement of refractive index using prisms and by total reflection.It is here that he first describes the Abbe refractometer he inventedin 18693 for determining the refractive index of fluids. This initial instrument includes Amici prisms andis essentially the same as a modern Abbe refractometer, thoughwithout temperature jacketing. Initially, Carl Zeiss producedthis instrument for internal use, and for special clients. Itwasn’t until after 18814 that the Abbe refractometerwas offered in Zeiss microscope catalogs, though without illustrations.Carl Zeiss published its first instrument catalog in 1893, a resultof the formation of a new optical instruments department underthe direction of Dr. C. Pulfrich.5 The Abbe refractometerfeatures prominently in this catalog, both with and without waterjacketed prisms, and as the Wolney Butter refractometer.

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Determining Concentrations Of Solutions

Determining the concentration of a solute in a solution is probably the most popular use of refractometry. For example, refractometer-based methods have been developed for determining the percentage of sugar in fruits, juices, and syrups, the percentage of alcohol in beer or wine, the salinity of water, and the concentration of antifreeze in radiator fluid. Many industries use refractometer-based methods in quality control applications.

In most cases the refractive index is linearly related to the percentage of dissolved solids in a solution . By comparing the value of the refractive index of a solution to that of a standard curve the concentration of solute can be determined with good accuracy. Many refractometers contain a “Brix” scale that is calibrated to give the percentage of sucrose dissolved in water.