Name: organic lab glassware and safe handling
Uploaded: 2020-03-26T07:22:27.000Z
Duration: 3 min 8 s
Channel: JoVE

K12 Standards

Texas Essential Knowledge and Skills

High School

Chemistry

CHEM.1

CHEM.1.D

Basic Organic Chemistry Techniques

Les procédures de laboratoire en chimie organique utilisent généralement des équipements et des techniques de verrerie standard. Les béchers et les erlenmeyers sont souvent utilisés pour mélanger et maintenir simplement des solvants. Les flacons à fond rond à col court ou long sont utilisés pour les réactions à haute température ou sous vide. En effet, la forme ronde est plus résistante à la fissuration dans ces conditions.
Les réactions thermiques sont une procédure de laboratoire courante. Cependant, un bec Bunsen n’est généralement pas utilisé pour les composés organiques car ils sont inflammables. Lors du chauffage d’une réaction dans un bécher ou un erlenmeyer, une plaque chauffante avec un agitateur magnétique est généralement utilisée. Lors du chauffage d’une réaction dans un ballon à fond rond, un bain-marie ou un ballon chauffant est utilisé pour s’adapter à la forme du ballon.
De nombreuses réactions doivent être chauffées à une certaine température pendant une durée spécifique pour se dérouler. Ces réactions sont effectuées sous reflux. Une configuration à reflux utilise un ballon à fond rond contenant un solvant dont le point d’ébullition chevauche la température optimale de la réaction. Un condenseur est monté sur le ballon, et l’eau froide entre par le bras inférieur et sort par le bras supérieur. Au fur et à mesure que le mélange est chauffé et agité, le solvant s’évapore puis se condense à nouveau dans le ballon, préservant ainsi le volume de réaction.
Une autre technique couramment utilisée dans le laboratoire de chimie organique est la filtration, qui est une méthode pour séparer les solides des liquides. La filtration par gravité est la technique de filtration la plus simple utilisée pour séparer les solides granulaires insolubles. Cette configuration se compose d’un erlenmeyer, d’un entonnoir conique et d’un morceau de papier filtre plié. Le mélange est versé dans l’entonnoir et le liquide passe dans le ballon, appelé filtrat. Les solides restent sur le papier filtre.
Une technique de filtration plus rapide est la filtration sous vide. Ici, un entonnoir Büchner est relié à une fiole filtrante à l’aide d’un adaptateur en caoutchouc. Le ballon filtrant ressemble à un erlenmeyer, mais il est doté d’un bras latéral qui relie le ballon au vide via un tube à vide. Ensuite, un morceau plat de papier filtre est placé à l’intérieur de l’entonnoir et mouillé légèrement avant que l’aspirateur ne soit lentement allumé. Le liquide est aspiré à travers le papier filtre dans le ballon, tandis que le solide est retenu sur le papier filtre.
 Dans ce laboratoire, vous effectuerez une réaction simple pour former de l’acide benzoïque, ce qui vous permettra de pratiquer des techniques simples de chimie organique, comme le pesage des solides, la mesure du volume et la filtration sous vide. Vous pratiquerez ensuite la technique réflexe à l'aide de tétrahydrofurane.

techniques de base de la chimie organique

La verrerie en chimie organique
Il existe des pièces de verrerie standard qui sont utilisées dans le laboratoire de chimie organique. Les béchers et les erlenmeyers sont généralement utilisés pour un mélange simple ou pour contenir des solvants, mais ils ne doivent pas être utilisés pour mesurer le volume, à moins que seul un volume approximatif ne soit nécessaire. La verrerie peut être divisée dans les catégories suivantes :
<ol>
	<li style="font-size :17px">Verrerie volumétrique - Cela inclut la verrerie telle que les cylindres gradués, les pipettes en verre volumétriques et les flacons jaugés. Le but de ces articles est de mesurer ou de distribuer un volume précis d’une substance. Un cylindre gradué est généralement utilisé pour mesurer les volumes dans un laboratoire organique. Le cylindre gradué a une forme cylindrique longue avec des repères de volume sur le côté. Il est essentiel d’utiliser le plus petit cylindre gradué possible pour le volume nécessaire afin de minimiser les erreurs. Par exemple, un cylindre gradué de 25 ml est suffisant pour mesurer 20 ml de réactif, mais il n’est pas précis pour mesurer un volume plus petit, comme 5 ml. Cependant, n’utilisez pas une bouteille graduée de 25 mL pour mesurer 100 mL en mesurant quatre volumes de 25 mL ; il est préférable d’utiliser le cylindre gradué de 100 ml.</li>
	<li style="font-size :17px">Confinement de la réaction - Ces pièces spécialisées peuvent être utilisées pour abriter une réaction chimique organique. Les flacons à fond rond sont un exemple de cette verrerie. Contrairement aux erlenmeyers, les flacons à fond rond offrent une plus grande surface et offrent donc un chauffage ou un refroidissement plus uniforme. Les flacons à fond rond sont utilisés pour effectuer des réactions sous haute chaleur ou sous vide car leur forme ronde est plus résistante à la fissuration. Dans cette catégorie se trouvent également des verreries spécialisées appelées condenseurs, qui sont utilisées pour collecter les vapeurs gazeuses et les condenser dans la phase liquide à collecter.</li>
	<li style="font-size :17px">Filtration - Ces morceaux de verrerie sont principalement utilisés pour aider à isoler les précipités d’un mélange réactionnel. Pour isoler les précipités solides, un appareil de filtration est nécessaire. La configuration la plus simple utilise un entonnoir en verre attaché à un erlenmeyer. À l’intérieur de l’entonnoir se trouve un morceau de papier filtre. Le mélange réactionnel contenant le solide est versé dans l’entonnoir, et la gravité tirera le liquide vers le bas dans le flacon, laissant derrière lui le solide. C’est ce qu’on appelle la filtration par gravité. Cependant, cette configuration peut nécessiter une longue période de temps pour filtrer le solide. Une installation de filtration sous vide remplace l’erlenmeyer par un erlenmeyer avec un bras latéral et l’entonnoir en verre par un entonnoir filtrant en porcelaine appelé entonnoir Büchner. Ce bras latéral est fixé à une source d’aspiration. Comme précédemment, le mélange réactionnel est versé dans l’entonnoir du filtre et la filtration est facilitée par la force du vide.</li>
	<li style="font-size :17px">Séparation - Ces flacons ou entonnoirs spécialisés sont principalement utilisés pour les extractions en phase liquide-liquide, qui est une technique qui permet de séparer les produits en utilisant des solvants de différentes polarités ou hydrophobies. Ces liquides non miscibles vont former une solution hétérogène qui se sépare en deux phases. Les entonnoirs séparateurs sont dotés d’une vanne connue sous le nom de robinet d’arrêt au fond, permettant de séparer les phases en les versant dans un nouveau récipient.</li>
	<li style="font-size :17px">Transport - Cette verrerie se compose principalement de bouteilles ou de flacons avec un bouchon correspondant. Cette verrerie est principalement utilisée pour transporter en toute sécurité des matériaux potentiellement dangereux.</li>
	<li style="font-size :17px">Utilisation générale - Cette catégorie comprend des objets en verre tels que des béchers, des flacons Erlenmeyer, des tiges de verre et toute autre pièce diverse.</li>
</ol>
Pesage des réactifs organiques
Les réactifs organiques peuvent se présenter sous plusieurs formes, et il est important de pratiquer une bonne technique de laboratoire lors de l’obtention de ces réactifs pour une utilisation dans des expériences. Examinez toujours la fiche signalétique d'un réactif pour déterminer les dangers potentiels lors de l'utilisation de celui-ci. Les réactifs solides doivent être mesurés à l’aide de bateaux de pesée ou de papier de pesée et du type de balance approprié.
Si une mesure précise est requise, utilisez une balance analytique. Si une grande quantité de réactif doit être utilisée, utilisez une balance à chargement par le haut. Placez un bateau de pesée ou du papier de pesée sur la balance et appuyez sur le bouton « tare ». La fonction de tare annulera la masse du papier de pesée. Utilisez toujours des spatules pour transférer les réactifs solides de l’alimentation au bateau de pesée. Ne réutilisez jamais la même spatule pour différents réactifs, car cela pourrait contaminer les réactifs d’origine. Et ne retournez jamais l’excès de réactif dans la bouteille de stock. Au lieu de cela, jetez-le de la manière appropriée comme indiqué.
Lors du transfert du solide dans le récipient approprié, utilisez un petit entonnoir pour verser soigneusement le solide à l’intérieur. S’il reste du solide, utilisez une petite quantité de solvant à utiliser sur le bateau de pesée et transférez-le dans le ballon.
Les liquides organiques peuvent être mesurés à l’aide d’une verrerie volumétrique, telle qu’un cylindre gradué. Calculez le volume du liquide à l’aide de sa densité, puis tarez le ballon de réaction sur la balance. À l’aide d’une pipette ou d’un cylindre gradué, transférer le volume directement dans la fiole de réaction. Suivez les directives du type spécifique de verrerie. Ne réutilisez jamais le même morceau de verrerie pour plusieurs réactifs et ne retournez jamais l’excès de réactif dans les flacons de liquide. Pour les liquides, c
Réactions organiques de chauffage
Parfois, la chaleur est nécessaire pour permettre à une réaction chimique organique de se produire. Dans le cadre général du laboratoire, la chaleur est généralement appliquée à l’aide d’un bec Bunsen avec une flamme de gaz directe. Dans les laboratoires de chimie organique, une flamme nue provenant d’un bec Bunsen peut créer une situation dangereuse. Les réactifs organiques, en particulier les solvants, sont hautement combustibles et certains forment des vapeurs avec une relative facilité. Pour cette raison, les becs Bunsen ne sont pas utilisés dans les laboratoires de chimie organique.
Au lieu de cela, des bains chauffants, des plaques chauffantes ou des manchons sont utilisés pour fournir une source indirecte de chaleur. Des plaques chauffantes avec fonction d’agitation magnétique sont utilisées pour chauffer les béchers et les flacons Erlenmeyer. Les ballons chauffants sont conçus pour chauffer en toute sécurité un ballon à fond rond de volumes variables. Les bains-marie sont utilisés lorsque la température de la réaction n’a pas besoin de dépasser 100 °C. Une réaction dans la verrerie est immergée dans un bain-marie qui est chauffé par une plaque chauffante. La température est modulée à la plage appropriée. Si la température requise doit dépasser 100 °C mais pas 250 °C, un manchon en silicone peut être utilisé. Si la température doit dépasser 250 °C, un bain de sable peut être utilisé.
De nombreuses réactions nécessitent d’être chauffées à une certaine température pendant de longues périodes pour se dérouler. Cependant, si une réaction est chauffée pendant une longue période, le solvant peut s’évaporer, provoquant une perte de solution réactionnelle. Au lieu de cela, une configuration à reflux est souvent utilisée, qui utilise une fiole à fond rond contenant un solvant. Le point d’ébullition du solvant chevauche la température optimale de la réaction. Le ballon à fond rond est fixé à un support et un condenseur est monté sur le ballon. L’eau froide s’écoule à travers le condenseur du bras inférieur au bras supérieur pendant que le mélange est chauffé et agité. Au fur et à mesure que le mélange est chauffé, le solvant s’évapore puis se condense dans le ballon, préservant ainsi le volume de réaction.

Techniques de base de la chimie organique

La verrerie en chimie organique
Il existe des pièces de verrerie standard qui sont utilisées dans le laboratoire de chimie organique. Les béchers et les flacons Erlenmeyer sont ...

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JoVE Lab Manual

Chimie

organic lab glassware and safe handling

Organic chemistry labs use specific glassware, careful weighing steps, and controlled heating to keep reactions safe and accurate. Beakers and Erlenmeyer flasks are often used for mixing or holding solvents, but they are not meant for measuring volume unless only an approximate amount is needed.

Volumetric glassware is used when a precise volume matters. This group includes graduated cylinders, volumetric pipettes, and volumetric flasks. A graduated cylinder is commonly used in the organic lab because it has volume markings along a long cylinder. It is best to choose the smallest cylinder that can measure the needed amount. For example, a 25-mL graduated cylinder can measure 20 mL, but it is not accurate for a small volume like 5 mL. It is also better to use a 100-mL graduated cylinder for 100 mL than to measure four separate 25-mL portions.

Other glassware is built to hold reactions or help them proceed under specific conditions. Round-bottom flasks provide more surface area than Erlenmeyer flasks and allow more even heating or cooling. They are useful for reactions under high heat or vacuum because their round shape is less likely to crack. Condensers are another important type of glassware. They collect vapor and turn it back into liquid so it can be collected again.

Glassware is also used for filtration, separation, transport, and general lab work. To remove solid precipitates, a simple gravity filtration setup uses a glass funnel, filter paper, and an Erlenmeyer flask. The liquid passes through while the solid stays behind, but the process can take a long time. A vacuum filtration setup is faster and uses a vacuum flask with a side arm, a B&amp;uuml;chner funnel, and a vacuum source. For liquid-liquid phase extractions, separatory funnels are used to split immiscible liquids into two layers. These flasks and funnels separate products by using solvents with different polarities or hydrophobicities. The stopcock at the bottom lets the layers be drained into a new container. Bottles and vials with matching caps are used for safe transport of hazardous material. Beakers, Erlenmeyer flasks, glass rods, and other mixed-purpose items fall into the general use category.

Organic reagents also need careful handling during weighing and transfer. Students should always check the reagent MSDS, or material safety data sheet, for hazards first. Solid reagents are measured on weighing boats or weighing paper with the correct balance. Use an analytical balance for precise mass and a top-loading balance for larger amounts. After placing the weighing boat on the balance, press tare to zero out its mass. Transfer solids with spatulas, but never use the same spatula for different reagents. Do not return extra reagent to the stock bottle. Instead, discard it as instructed. A small funnel can help move the solid into the reaction vessel, and any residue on the boat can be rinsed in with a small amount of the solvent being used.

Liquids are measured with volumetric glassware such as a graduated cylinder. Their volume can be calculated from density, and the reaction flask can be tared on the balance before transfer. A pipet or graduated cylinder is then used to add the liquid directly to the flask. The same piece of glassware should not be reused for multiple reagents, and excess liquid should never go back into the stock bottle. When heat is needed for an organic reaction, a Bunsen burner is avoided because organic solvents and vapors can ignite easily. Instead, labs use hotplates, heating baths, or heating mantles. Hotplates with magnetic stirring heat beakers and Erlenmeyer flasks. Heating mantles are made for round-bottom flasks. Water baths are used when the reaction temperature stays below 100 &amp;deg;C. Silicone mantles are used when the temperature must be above 100 &amp;deg;C but below 250 &amp;deg;C, and sand baths are used above 250 &amp;deg;C. For long heating times, a reflux setup helps prevent solvent loss. A round-bottom flask with solvent is clamped to a stand, a condenser is attached, and cold water flows from the bottom arm to the top arm while the mixture is heated and stirred. The solvent vapor condenses and returns to the flask, which keeps the reaction volume steady.

Organic Lab Glassware and Safe Handling

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Balancing Equations and Reactant Limits

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Oxidation States in Redox Reactions

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Gas Laws Behind the Ideal Gas Equation

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acid and base concentrations

Acids, Bases, and pH in Titration

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buffers

Buffer pH and the Common Ion Effect

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solubility

Solubility in Water and Other Solvents

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Flame Test Metal Color Clues

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balmer series

Hydrogen Emission Lines

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beer's law

Absorbance Spectra and Beer-Lambert Analysis

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concentration dependence

Reaction Order and Rate Constants

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temperature dependence

Reaction Rate, Arrhenius, and Catalysts

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Battery Power from Redox Reactions

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electrolytic cells

Electroplating with Electrolytic Cells

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Recording a Reproducible Lab Experiment

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basic organic chemistry techniques

Organic chemistry labs use specific glassware, careful weighing steps, and controlled heating to keep reactions safe and accurate. Beakers and Erlenmeyer flasks are often used for mixing or holding solvents, but they are not meant for measuring volume unless only an approximate amount is needed. Volumetric glassware is used when a precise volume matters. This group includes graduated cylinders, volumetric pipettes, and volumetric flasks. A graduated cylinder is commonly used in the organic lab...

melting points

How Impurities Change Melting Points

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boiling points

Boiling Point and Vapor Pressure

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recrystallization

Purifying Crystals by Solubility

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extraction

Separating Mixtures with Solvent Extraction

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simple distillation

Separating Liquids by Boiling Point

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steam distillation

Steam Distillation and Low-Boiling Separation

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thin-layer chromatography

TLC Separation by Polarity

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column chromatography

Separating Mixtures by Polarity

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esterification

Ester Formation and Everyday Fragrances

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identification of unknown aldehydes and ketones

identification-of-unknown-aldehydes-and-ketones

Carbonyl Tests for Aldehydes and Ketones

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uv-vis spectroscopy of dyes

How Dyes Absorb Visible Light

Dyes absorb visible light because their molecular structure lets them interact with specific wavelengths. When light hits a substance, some light is absorbed and the rest is reflected or transmitted. The color we see depends on the wavelength that is reflected. A blue substance reflects blue light, around 430 to 480 nm, and absorbs the complementary orange region, around 590 to 630 nm. Compounds that do not absorb in the visible range appear colorless to the human eye. Light also has energy and...

identifying alcohols

Alcohol Tests for Primary, Secondary, and Tertiary

Alcohol tests can help sort alcohols by structure and reactivity. Alcohols are organic molecules with a hydroxyl group attached to an alkyl or aryl group, written as ROH. If the carbon with the hydroxyl group has one R group, the alcohol is primary. If it has two R groups, it is secondary. If it has three R groups, it is tertiary. Alcohols can also be aromatic when they contain a benzene ring. Phenol is the simplest aromatic alcohol. To identify an alcohol, chemists can use its chemical...

chemistry

Des vidéos complètes, axées sur le programme de cours pour les travaux pratiques de Chimie, adaptées à la fois aux professeurs et aux étudiants.

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Learn how high school organic chemistry labs use glassware, filtration, separatory funnels, weighing tools, and safe heating methods for reactions.

Organic Lab Glassware and Safe Handling | JoVE K12

Préparez l'enseignement de Techniques de base de la chimie organique avec ce guide instructeur de 3 minutes. Couvre les principales étapes de préparation pour le laboratoire Chemistry sur JoVE Lab Manual.

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Suivez les procédures étape par étape de Techniques de base de la chimie organique dans cette vidéo de protocole étudiant de 16 minutes. Fait partie de la collection Chemistry sur JoVE Lab Manual.

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Scientific Laws and Theories

Scientific Laws

In science, a law is defined as a concise, verbal or mathematical, statement that summarizes a vast number of experimental observations. ...

The Scientific Method

Chemistry is an empirical science. Scientists often pose questions to understand the chemistry in everyday life and seek answers to these questions. To ...

CHEM.1.A

What is an Experiment?

An experiment is a planned activity carried out under controlled conditions. The purpose of an experiment is to investigate the relationship between two ...

Study Design in Statistics

A study design is a set of techniques that allow a researcher to collect and analyze data from different variables defined for a specific research ...

Observational Studies

Observational studies are a type of analytical study where researchers observe events without any interventions. In other words, the researcher does not ...

Experimental Designs

An experimental design is a systematic process that allows researchers to evaluate the relationship between dependent and independent variables. There are ...

Randomized Experiments

The randomization process involves assigning study participants randomly to experimental or control groups based on their probability of being equally ...

Crossover Experiments

Crossover experiments, also called the repeated-measurements design, is a study design in which all experimental units are exposed to all treatments in ...

Controls in Experiments

When conducting an experiment, it is crucial to have control to reduce bias and accurately measure the dependent variables. It also marks the results more ...

Bias

Bias refers to any tendency that prevents a question from being considered unprejudiced. In research, bias occurs when one outcome or answer is selected ...

Blinding

Blinding is a commonly used method of not telling participants which treatment a subject is receiving. Blinding is a critical part of a randomized control ...

CHEM.1.B

Proper Personal Protective Equipment

Robert M. Rioux &#38; William A Elliott, Pennsylvania State University, University Park, PA
Hazards are many and varied in the laboratory, but the right ...

Emergency Eyewash and Shower Stations

Robert M. Rioux, Pennsylvania State University, University Park, PA
The Occupational Safety and Health Administration (OSHA) mandates that an emergency ...

Electrical Safety

Robert M. Rioux &amp; Suprita Jharimune, Pennsylvania State University, University Park, PA
Among the many hazards present in the laboratory, electrical ...

Working with Centrifuges

Source: Robert M. Rioux &amp; Suprita Jharimune, Pennsylvania State University, University Park, PA
Earth's gravitational force is capable of separating ...

Working with Hot and Cold Sources

Source: Robert M. Rioux &amp; Suprita Jharimune, Pennsylvania State University, University Park, PA
Working with extreme temperatures, both high and low, ...

guidelines-in-case-of-a-laboratory-emergency

Guidelines in Case of a Laboratory Emergency

Robert M. Rioux &amp; Zhifeng Chen, Pennsylvania State University, University Park, PA
The most common laboratory emergencies include chemical spills, ...

chemical-storage-categories-hazards-and-compatibilities

Chemical Storage: Categories, Hazards And Compatibilities

Source: Robert M. Rioux &amp; Taslima A. Zaman, Pennsylvania State University, University Park, PA
While the use of various chemicals in experimental ...

Safe Handling of Mineral Acids

Source: Robert M. Rioux &#38; Taslima A. Zaman, Pennsylvania State University, University Park, PA
A mineral acid (or inorganic acid) is defined as a ...

Handling Chemical Spills

Source: Robert M. Rioux &#38; Taslima Zaman, Pennsylvania State University, University Park, PA
Since chemicals are commonly used for laboratory research ...

Proper Use of Autoclaves

Robert M. Rioux &amp; Zhifeng Chen, Pennsylvania State University, University Park, PA
Autoclaving is one of the most commonly used methods in the ...

Fume Hoods and Laminar Flow Cabinets

Robert M. Rioux &amp; William A. Elliott, Pennsylvania State University, University Park, PA
Fume hoods and laminar flow cabinets are engineering controls ...

handling-air-and-water-sensitive-chemicals-using-a-schlenk-line

Handling Air- and Water-Sensitive Chemicals Using a Schlenk Line

Robert M Rioux, Ajay Sathe, Zhifeng Chen, Pennsylvania State University, University Park, PA
The use of reagents sensitive to oxidation or moisture ...

proper-operation-of-vacuum-based-equipment

Proper Operation of Vacuum Based Equipment

Source: Robert M. Rioux, Ajay Sathe &#38; Zhifeng Chen, Pennsylvania State University, University Park, PA
Vacuum is required for a number of laboratory ...

Operating the Glovebox

Robert M Rioux, Ajay Sathe, Zhifeng Chen, Pennsylvania State University, University Park, PA 
A glovebox is an isolated enclosure that is designed to ...

operation-of-high-pressure-reactor-vessels

Operation of High-pressure Reactor Vessels

Robert M Rioux, Pennsylvania State University, University Park, PA
The use of gases in a synthetic chemistry laboratory is essential for carrying out a ...

CHEM.1.C

Lab Techniques

Measurement Accuracy
The ability to repeat an experiment and get the same results, or reproducibility, is essential in scientific research. However, ...

Scientific Measurement and Lab Skills

Two-Dimensional Graphs
Some chemistry experiments take the form of directly changing one property of the system that you are studying otherwise known as ...

Proper Lab Notebook Keeping

Organic Lab Notebook Keeping
Record keeping is a vital skill in science and organic chemistry labs. Without proper notes, descriptions, quantities, or ...

Glassware in Organic Chemistry
There are standard pieces of glassware that are used in the organic chemistry lab. Beakers and Erlenmeyer flasks are ...

Measurement: Standard Units

Every measurement provides three kinds of information: the size or magnitude of the measurement (a number), a standard of comparison for the measurement ...

Measurement: Derived Units

The International System of Units or SI system, by international agreement, has fixed measurement units for seven fundamental properties: length, mass, ...

uncertainty-in-measurement-accuracy-and-precision

Uncertainty in Measurement: Accuracy and Precision

Scientists typically make repeated measurements of a quantity to ensure the quality of their findings and to evaluate both the precision and the accuracy ...

uncertainty-in-measurement-reading-instruments

Uncertainty in Measurement: Reading Instruments

Counting is the type of measurement that is free from uncertainty, provided the number of objects being counted does not change during the process. Such ...

CHEM.1.E

Scientific and engineering practices. The student, for at least 40% of instructional time, asks questions, identifies problems, and plans and safely conducts classroom, laboratory, and field investigations to answer questions, explain phenomena, or design solutions using appropriate tools and models. The student is expected to:

Organic Lab Glassware and Safe Handling

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