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

Os procedimentos laboratoriais em química orgânica normalmente utilizam equipamentos e técnicas de vidraria padrão. Béqueres e frascos Erlenmeyer são frequentemente usados para misturar e armazenar solventes simples. Os frascos de fundo redondo com gargalo curto ou longo são utilizados para reacções a altas temperaturas ou vácuo. Isso ocorre porque a forma redonda é mais resistente a rachaduras nessas condições.
As reações de aquecimento são um procedimento comum de laboratório. No entanto, um bico de Bunsen geralmente não é usado para compostos orgânicos porque eles são inflamáveis. Ao aquecer uma reação em um béquer ou frasco Erlenmeyer, normalmente é usada uma placa quente com um agitador magnético. Ao aquecer uma reação em um balão de fundo redondo, um banho-maria ou manta de aquecimento é usado para acomodar a forma do balão.
Muitas reações devem ser aquecidas a uma determinada temperatura por um período específico de tempo para prosseguir. Essas reações são realizadas sob refluxo. Uma configuração de refluxo usa um frasco de fundo redondo contendo um solvente cujo ponto de ebulição se sobrepõe à temperatura ideal da reação. Um condensador é instalado no frasco e a água fria entra no braço inferior e sai pelo braço superior. À medida que a mistura é aquecida e agitada, o solvente evapora e depois condensa de volta para o frasco, preservando o volume de reação.
Outra técnica comum usada no laboratório de química orgânica é a filtração, que é um método para separar sólidos de líquidos. A filtração por gravidade é a técnica de filtragem mais simples usada para separar sólidos insolúveis granulares. Essa configuração consiste em um frasco Erlenmeyer, um funil cônico e um pedaço de papel de filtro dobrado. A mistura é despejada no funil e o líquido passa para o frasco, chamado filtrado. Os sólidos permanecem no papel de filtro.
Uma técnica de filtragem mais rápida é a filtragem a vácuo. Aqui, um funil de Büchner é conectado a um frasco de filtro usando um adaptador de borracha. O frasco do filtro se parece com um frasco Erlenmeyer, mas tem um braço lateral que conecta o frasco ao vácuo por meio de um tubo de vácuo. Em seguida, um pedaço plano de papel de filtro é colocado dentro do funil e umedeço um pouco antes que o aspirador seja ligado lentamente. O líquido é sugado através do papel de filtro para o frasco, enquanto o sólido é retido no papel de filtro.
 Neste laboratório, você realizará uma reação simples para formar ácido benzóico, permitindo que você pratique técnicas simples de química orgânica, como pesar sólidos, medir volume e realizar filtração a vácuo. Em seguida, você praticará a técnica de reflexo usando tetrahidrofurano.

técnicas básicas de química orgânica

Vidraria em Química Orgânica
Existem peças padrão de vidro que são usadas no laboratório de química orgânica. Os copos e os frascos Erlenmeyer são normalmente usados para mistura simples ou para reter solventes, mas não devem ser usados para medir o volume, a menos que seja necessário apenas um volume aproximado. Os artigos de vidro podem ser divididos nas seguintes categorias:
<ol>
	<li style="font-size:17px">Vidraria volumétrica – Isso inclui vidraria, como cilindros graduados, pipetas de vidro volumétrico e frascos volumétricos. O objetivo desses itens é medir ou dispensar um volume preciso de uma substância. Um cilindro graduado é geralmente usado para medir volumes em um laboratório orgânico. O cilindro graduado tem uma forma cilíndrica longa com marcações de volume na lateral. É essencial usar o menor cilindro graduado possível para o volume necessário, a fim de minimizar o erro. Por exemplo, um cilindro graduado de 25 mL é adequado para medir 20 mL de reagente, mas não é preciso medir um volume menor, como 5 mL. No entanto, não use um cilindro graduado de 25 mL para medir 100 mL medindo quatro volumes de 25 mL; é melhor usar o cilindro graduado de 100 mL.</li>
	<li style="font-size:17px">Contenção de reação – Essas peças especializadas podem ser usadas para abrigar uma reação química orgânica. Frascos de fundo redondo são um exemplo desta vidraria. Ao contrário dos frascos Erlenmeyer, os frascos de fundo redondo fornecem mais área de superfície e, portanto, fornecem aquecimento ou resfriamento mais uniforme. Os frascos de fundo redondo são usados para realizar reações sob alto calor ou vácuo porque seu formato redondo é mais resistente a rachaduras. Nesta categoria também estão vidrarias especializadas conhecidas como condensadores, que são usadas para coletar vapores gasosos e condensá-los de volta à fase líquida a ser coletada.</li>
	<li style="font-size:17px">Filtração – Essas peças de vidro são usadas principalmente para ajudar a isolar precipitados de uma mistura de reação. Para isolar precipitados sólidos, é necessário um aparelho de filtração. A configuração mais simples utiliza um funil de vidro preso a um frasco Erlenmeyer. Dentro do funil há um pedaço de papel de filtro. A mistura de reação contendo o sólido é despejada no funil e a gravidade puxará o líquido para dentro do frasco, deixando para trás o sólido. Isso é conhecido como filtragem por gravidade. No entanto, essa configuração pode exigir um longo período de tempo para filtrar o sólido. Uma configuração de filtragem a vácuo substitui o frasco Erlenmeyer por um frasco a vácuo com um braço lateral e o funil de vidro por um funil de filtro de porcelana conhecido como funil de Büchner. Este braço lateral é conectado a uma fonte de vácuo. Como antes, a mistura de reação é despejada no funil do filtro e a filtragem é auxiliada pela força do vácuo.</li>
	<li style="font-size:17px">Separação – Esses frascos ou funis especializados são usados principalmente para extrações em fase líquido-líquido, que é uma técnica que permite a separação de produtos usando solventes com diferentes polaridades ou hidrofobicidades. Esses líquidos imiscíveis formarão uma solução heterogênea que se separa em duas fases. Os funis separatórios têm uma válvula conhecida como torneira na parte inferior, permitindo a separação das fases despejando-as em um novo recipiente.</li>
	<li style="font-size:17px">Transport – Este copo consiste principalmente em garrafas ou frascos com uma tampa correspondente. Esta vidraria é usada principalmente para transportar materiais potencialmente perigosos com segurança.</li>
	<li style="font-size:17px">Uso geral – Esta categoria é composta por artigos de vidro, como béqueres, frascos Erlenmeyer, hastes de vidro e quaisquer outras peças diversas.</li>
</ol>
Pesagem de reagentes orgânicos
Os reagentes orgânicos podem vir em várias formas, e é importante praticar uma boa técnica de laboratório ao obter esses reagentes para uso em experimentos. Sempre revise a MSDS de um reagente para determinar os perigos potenciais ao trabalhar com ele. Os reagentes sólidos devem ser medidos usando recipientes de pesagem ou papel de pesagem e o tipo apropriado de balança.
Se for necessária uma medição precisa, use uma balança analítica. Se uma grande quantidade de reagente for usada, use uma balança de carregamento superior. Coloque um barco de pesagem ou papel de pesagem na balança e aperte o botão "tara". O recurso de tara anulará a massa do papel de pesagem. Sempre use espátulas para transferir reagentes sólidos do suprimento para o recipiente de pesagem. Nunca reutilize a mesma espátula para reagentes diferentes, pois isso pode contaminar os reagentes de estoque. E nunca devolva o excesso de reagente ao frasco de estoque. Em vez disso, descarte-o da maneira apropriada, conforme as instruções.
Ao transferir o sólido para o recipiente apropriado, use um pequeno funil para despejar cuidadosamente o sólido dentro. Se restar algum sólido, utilizar uma pequena quantidade do solvente a utilizar no recipiente de pesagem e transferi-lo para o balão.
Os líquidos orgânicos podem ser medidos usando vidraria volumétrica, como um cilindro graduado. Calcular o volume do líquido utilizando a sua densidade e, em seguida, tarar o balão de reacção na balança. Utilizar uma pipeta ou um cilindro graduado para transferir o volume directamente para o balão de reacção. Siga as diretrizes para o tipo específico de vidraria. Nunca reutilize o mesmo pedaço de vidro para vários reagentes e nunca devolva o excesso de reagente aos frascos de estoque de líquidos. Para líquidos, c
Aquecimento de reações orgânicas
Às vezes, o calor é necessário para permitir que ocorra uma reação química orgânica. No ambiente geral de laboratório, o calor é comumente aplicado usando um bico de Bunsen com uma chama direta de gás. Nos laboratórios de química orgânica, uma chama aberta de um bico de Bunsen pode criar uma situação perigosa. Os reagentes orgânicos, particularmente os solventes, são altamente combustíveis e alguns formam vapores com relativa facilidade. Por esse motivo, os bicos de Bunsen não são usados em laboratórios de química orgânica.
Em vez disso, banhos de aquecimento, placas de aquecimento ou mantos são usados para fornecer uma fonte indireta de calor. Placas de aquecimento com funcionalidade de agitação magnética são usadas para aquecer béqueres e frascos Erlenmeyer. As mantas de aquecimento são projetadas para aquecer com segurança um frasco de fundo redondo com volumes variados. Os banhos-maria são usados quando a temperatura da reação não precisa exceder 100 °C. Uma reação em vidraria é imersa em banho-maria aquecido por uma placa quente. A temperatura é modulada para a faixa apropriada. Se a temperatura necessária precisar exceder 100 °C, mas não 250 °C, um manto de silicone pode ser usado. Se a temperatura exceder 250 °C, pode-se usar um banho de areia.
Muitas reações requerem ser aquecidas a uma certa temperatura por longos períodos de tempo para que prossigam. No entanto, se uma reação for aquecida por um longo período de tempo, o solvente pode evaporar, causando uma perda da solução de reação. Em vez disso, uma configuração de refluxo é freqüentemente usada, que usa um frasco de fundo redondo contendo um solvente. O ponto de ebulição do solvente se sobrepõe à temperatura ideal da reação. O balão de fundo redondo é preso a um suporte e um condensador é montado no frasco. A água fria flui através do condensador do braço inferior para o braço superior enquanto a mistura é aquecida e agitada. À medida que a mistura é aquecida, o solvente evapora e depois condensa de volta para o frasco, preservando o volume de reação.

Técnicas Básicas de Química Orgânica

Vidraria em Química Orgânica
Existem peças padrão de vidro que são usadas no laboratório de química orgânica. Copos e frascos Erlenmeyer são ...

Education

JoVE Lab Manual

Química

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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ideal gas law

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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Reaction Heat, Hess’s Law, and Calorimetry

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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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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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proper lab notebook keeping

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

Melting point helps identify an organic compound by showing the temperature where a solid turns into a liquid at 1 atmosphere of pressure. It is a physical property, like solubility, density, color, and electronegativity. Because the exact start of melting is hard to measure, the result is reported as a range. The lower end is when the first drops of liquid appear. The upper end is when the last solid has melted. Scientists compare this range with literature values to help identify a compound. <br...

boiling points

Boiling Point and Vapor Pressure

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recrystallization

Purifying Crystals by Solubility

Purifying crystals by solubility is a key organic chemistry technique. Recrystallization uses differences in solubility to separate a desired solid product from starting materials, solvent, and impurities. It is one of the three standard purification methods, along with distillation and extraction. Solubility is the maximum amount of a substance that can dissolve in a fixed volume of solvent at a given temperature. Different solutes dissolve in different solvents, and their behavior can vary...

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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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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How Dyes Absorb Visible Light

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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

Vídeos abrangentes e focados no currículo para instrutores e alunos de cursos introdutórios de laboratório de química

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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

Prepare-se para ensinar Técnicas Básicas de Química Orgânica com este guia do instrutor de 3 minutos. Abrange as principais etapas de preparação para o laboratório Chemistry no JoVE Lab Manual.

Preparação do Instrutor para Técnicas Básicas de Química Orgânica em Chemistry - 4.4K+ visualizações | JoVE Lab Manual

Siga os procedimentos passo a passo de Técnicas Básicas de Química Orgânica neste vídeo de protocolo estudantil de 16 minutos. Parte da coleção Chemistry no JoVE Lab Manual.

Protocolo do Estudante para Técnicas Básicas de Química Orgânica em Chemistry - 30K+ visualizações | JoVE Lab Manual

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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