Name: separating mixtures with solvent extraction
Uploaded: 2020-03-26T07:22:28.000Z
Duration: 2 min 55 s
Channel: JoVE

抽出は、混合物から成分を分離する技術です。抽出については、すでにご存じでしょう。お茶を淹れるときはいつでも、カフェインやフレーバーなどの水溶性化合物が茶葉からお湯に抽出されます。これは固液抽出の一例です。
液液抽出は、混合物が2つの非混和性液相に溶解する別のタイプの抽出です。溶媒は非混和性、つまり混合せず、別々の相でなければなりません。液液抽出は、より密度の高い溶媒が底に沈殿し、密度の低い溶媒が上に座るように、分離漏斗で行われます。その後、各溶質化合物は、最も溶解しやすい相に移動します。したがって、極性の異なる溶媒を選択することが重要です。
一般に、非極性溶質は有機相に分配され、極性溶質は水相に分配されます。分配係数Kは、有機相の溶質濃度と水相の溶質濃度の比です。溶質が分離すると、2つの異なる相が収集されます。両方のフェーズで各コンポーネントの残留物が存在する可能性が高いことに注意してください。
酸塩基抽出は、溶解度の違いに基づいて酸性化合物と塩基性化合物を分離する特殊なタイプの液液抽出です。酸は水に溶解するとプロトンを提供する化合物であり、塩基はプロトンを受け入れる化合物であることを思い出してください。
酸性化合物を分離するために、塩基を混合物に添加する。塩基は酸性化合物からのプロトンを受け入れ、イオン性にします。逆に、酸を加えると、プロトンが塩基性化合物に移動します。どちらの場合も、イオン性化合物は水相に移動し、中性化合物は有機相に分配されます。イオン性化合物を回収し、脱プロトン化または再プロトン化して元の化合物に戻します。
このラボでは、セルロース、安息香酸、カフェインの混合物を分離します。まず、抽出とろ過を使用してセルロースを分離します。次に、安息香酸とカフェインを分離するための酸塩基抽出を行います。

抽出

抽出
抽出は、有機化学で標的化合物を単離するために使用される一般的な手法です。抽出プロセスでは、溶質をある相から別の相に移して、未反応の出発物質や不純物から分離します。抽出は、沸点の高い溶媒など、蒸発によって除去するのが難しい反応溶媒からの溶質の分離を容易にするためにも使用されます.<span style="color: rgb(0, 0, 0);font-family: Roboto, RobotoDraft, Helvetica, Arial, sans-serif;フォントサイズ:13px;font-style: normal;font-variant-ligatures: 正常;font-variant-caps: ノーマル;フォントの太さ:400;letter-spacing: normal;孤児:2;text-align: 開始;テキストインデント:0px;text-transform: なし;white-space: あらかじめ折り返します。未亡人:2;ワードスペース:0px;-webkit-text-stroke-width:0px;背景色:rgb(255、255、255);text-decoration-style: イニシャル;text-decoration-color: 初期;display: inline !important;float: なし;"> 一般的に、抽出には3つのタイプがあります。まず、固液抽出では、溶質が固相から液相に移されます。液液抽出では、溶質はある液体から別の液体に移されます。酸塩基抽出では、溶質がイオン性化合物に変換され、有機相から水相に移行します。抽出の一般的な例は、コーヒーや紅茶を淹れることです。カフェインや植物の香料、匂いなどを含む固相は、お湯によって液相に抽出されます。
液液抽出
液液抽出は、水相に溶解した有機化合物を有機溶媒に移すか、または未反応の反応物、塩、およびその他の水溶性不純物を水相に移すために使用され、目的の有機化合物を有機相に残します。非混和性液体とは、完全に混合しても均質な溶液を形成しない液体です。代わりに、非混和性の液体は、油と水のように異なる相に分離します。
液液抽出は、水相に溶解した有機化合物を有機溶媒に移します。液液抽出を行うには、まず、溶質を含む水溶液を分離漏斗に加えます。次に、非水溶性の有機溶媒を分離液漏斗に添加します。漏斗の内容物がよく混合されると、有機化合物は水相よりも有機相への溶解度が高いことに基づいて有機相に分配されます。
2つの溶媒は混和性がないため、2つの液体は個別の層を形成し、密度の高い液体が下部に、密度の低い液体が上部に存在します。2つのフェーズが2つの層に落ち着いたら、セパリーファンネルの下部にあるストップコックを開き、1つの層を流出させることで、2つのフェーズを分離します。溶質が除去された液体はラフィネートと呼ばれ、溶質を得た液体は抽出物と呼ばれます。
有機化合物は、各相での溶解度に基づいて2つの層間で分配されます。平衡は、溶質の化学ポテンシャルが2つの相で同じである場合に達成されます。溶質の分配係数Kは、有機層内のサンプルの濃度を水相中の濃度で割った比率です。分配係数は、抽出に使用される溶質と溶媒のペアの両方に依存する定数です。分配係数は、2つの溶媒のそれぞれに対する溶質の選好の表現です。分配係数が大きい溶質は、有機溶媒層に抽出される傾向が高くなります。分配係数が小さい溶質は、水相への移行を好みます。
液液抽出にどの溶媒ペアを使用するかを決定することは、重要なステップです。使用する溶媒を選択する際には、次の点を考慮してください:まず、溶質は水よりも溶媒に溶けやすい必要があります。したがって、潜在的な溶媒ペアにおける溶質の分配係数を知る必要があります。第二に、溶媒ペアは水と混和せず、混合時に均質な溶液を形成してはなりません。第三に、溶媒は不活性でなければならず、溶質と反応してはなりません。溶媒は、溶質から容易に除去できるように、揮発性であることも必要です。水非混和性有機溶媒は、一般に非極性または低極性を有する。
また、上層と下層の同一性を判断するために、溶媒の密度を知ることも重要です。ほとんどの有機液体は、塩素化有機溶剤を除いて、水よりも密度が低く、分離漏斗の底に沈殿します。
酸塩基抽出
酸塩基抽出は、酸塩基特性に基づいて有機化合物を分離する液液抽出の一種です。溶質が酸または塩基の場合、pHが変化するとその電荷も変化します。一般に、ほとんどの有機化合物は中性であるため、水よりも有機溶媒に溶けやすいです。ただし、有機化合物がイオン性になると、水に溶けやすくなります。これは、有機酸または塩基化合物を有機相から水相に抽出するのに有用です。
酸塩基抽出は、溶質を水溶性の塩の形に変換することにより、この特性を利用し、それによってその溶解度を変化させます。有機化合物とその塩の溶解度は、技術が効果的であるためには劇的に異なる必要があります。
たとえば、有機カルボン酸、アミン、および中性化合物を含む混合物を考えてみます。炭素が6個以上からなるカルボン酸は、水に不溶で、有機溶媒に完全に溶けます。しかし、それらの共役塩基(イオン性化合物)は水溶性であり、有機溶媒には不溶性です。少なくとも7つの炭素からなるアミンは、水には不溶ですが、有機溶媒には溶けます。そのアミン(イオン性化合物)の共役酸は水溶性で、有機溶媒に不溶です。
塩基と反応すると、カルボン酸はその塩の形に中和されます。混合物中の他の化合物は中性のままです。カルボン酸が塩に変換されると、水相に分配されますが、中性化合物は有機相に残ります。
酸塩基抽出は、pKaに大きな差がある2つの弱酸または2つの弱塩基を分離するためにも使用されます。酸の場合、pKa値が小さい比較的強い酸を弱塩基を用いて塩に中和する。弱塩基は弱酸と効率的に反応せず、強い酸のみが塩に変換されます。次に、抽出中に塩を水相に抽出します。このプロセスは弱塩基についても同様で、比較的強い塩基が弱酸を使用して塩に中和されます。
参照
<ol>
	<li style="font-size:17px">ハリス、ワシントンD.C.(2015年)。定量的化学分析。ニューヨーク州ニューヨーク:WHフリーマンアンドカンパニー。</li>
</ol>

抽出
抽出は、有機化学で標的化合物を単離するために使用される一般的な手法です。抽出プロセスでは、溶質が転写されます...

Education

JoVE Lab Manual

Chemistry

化学

Extraction

separating mixtures with solvent extraction

Solvent extraction is a common way to separate and isolate a target compound in organic chemistry. In this process, a solute moves from one phase to another so it can be separated from unreacted starting materials or impurities. Extraction is also useful when a product is dissolved in a reaction solvent that is hard to remove by evaporation, such as a solvent with a high boiling point.

There are three main types of extraction. In solid-liquid extraction, the solute moves from a solid phase into a liquid phase. In liquid-liquid extraction, the solute moves from one liquid into another. In acid-base extraction, the solute is changed into an ionic compound and moved from an organic phase into an aqueous phase. A familiar example is brewing coffee or tea, where hot water extracts caffeine, plant flavors, and odors from the solid material.

Liquid-liquid extraction is used when an organic compound is dissolved in water or when water-soluble impurities need to be removed from an organic product. It works with immiscible liquids, which are liquids that do not form one uniform solution, even after mixing. Oil and water are a common example. To carry out this extraction, the aqueous solution is placed in a separatory funnel, and a non-water-soluble organic solvent is added. After mixing, the compound partitions into the phase where it is more soluble.

Because the two liquids are immiscible, they separate into layers after settling. The denser liquid forms the bottom layer, and the less dense liquid stays on top. The layers are then separated by opening the stopcock at the bottom of the separatory funnel and letting one layer drain out. The layer that loses the solute is called the raffinate, and the layer that gains the solute is called the extract. At equilibrium, the solute has the same chemical potential in both phases.

The partition coefficient, K, describes how a solute divides between the two layers. It is the concentration in the organic layer divided by the concentration in the aqueous layer. This value depends on the solute and the solvent pair used. A large partition coefficient means the solute prefers the organic layer. A small partition coefficient means the solute prefers the aqueous layer. Choosing the right solvent pair is important, so the solute should be more soluble in that solvent than in water, the two solvents should be immiscible, and the solvents should be inert and volatile. The water-immiscible organic solvent is usually non-polar or low in polarity.

Knowing density is also important because it tells which layer is on top and which is on the bottom. Most organic liquids are less dense than water and rise to the top, although chlorinated organic solvents are an exception and can settle to the bottom. Acid-base extraction is a special type of liquid-liquid extraction that separates organic compounds based on acid-base behavior. When pH changes, the charge on an acid or base can change too. Neutral organic compounds are usually more soluble in organic solvents, but ionic forms are more soluble in water.

This property lets chemists turn an organic acid or base into a water-soluble salt. The salt and the neutral compound must have very different solubilities for the method to work well. For example, a mixture may contain an organic carboxylic acid, an amine, and a neutral compound. Carboxylic acids with six carbons or more are insoluble in water and soluble in organic solvents, but their conjugate bases are water-soluble and insoluble in organic solvents. Amines with at least seven carbons are insoluble in water and soluble in organic solvents, while their conjugate acids are water-soluble and insoluble in organic solvents.

When a base is added, the carboxylic acid is neutralized to its salt form, while the other compounds remain neutral. The salt then moves into the aqueous phase, and the neutral compounds stay in the organic phase. Acid-base extraction can also separate two weak acids or two weak bases when their pKa values are far enough apart. For weak acids, the stronger acid with the smaller pKa is converted to a salt using a weak base, while the weaker acid is not reacted much. The same idea applies to weak bases, but a weak acid is used to neutralize the stronger base.

Separating Mixtures with Solvent Extraction

separating-mixtures-with-solvent-extraction

lab techniques

Measuring with Accuracy in the Lab

Measuring with accuracy in the lab starts with careful records, the right tools, and correct reading of data. Scientists use lab notebooks to record how an experiment was done. These notes include the amounts of materials used and each step of the procedure. Without that record, an experiment cannot be repeated in the same way. Balances and glassware are used to measure solids and liquids for experiments. The precision of a measurement depends on the equipment used. Digital balances show the...

scientific measurement and lab skills

Graphs, Curve Fit, and Standard Deviation

Two-dimensional graphs help students compare an independent variable with a dependent variable in science data. In a chemistry example, temperature is the independent variable and volume is the dependent variable. After data are collected, the relationship between the two measurements must be quantified so it can be evaluated and compared with other relationships. A graph can also show when no relationship exists between the two variables. To make a two-dimensional graph, each data point needs...

stoichiometry, product yield, and limiting reactants

stoichiometry-product-yield-and-limiting-reactants

Balancing Equations and Reactant Limits

Chemical equations show how reactants change into products during a reaction. Stoichiometry is the study of the relative amounts of reactants and products. It is based on the Law of Conservation of Mass, which says matter is neither created nor destroyed. Because atoms are only rearranged, the number and identity of atoms must match on both sides of a reaction. That is why a chemical equation must be balanced. A balanced equation has the same number of atoms for each element in the reactants...

redox reactions

Oxidation States in Redox Reactions

Oxidation states help identify redox reactions. In a redox reaction, oxidation is the loss of one or more electrons, and reduction is the gain of one or more electrons. These reactions are often tracked by changes in oxidation state, also called oxidation number. Each atom in a molecule has an oxidation state. This number shows how oxidized an atom is compared with its free elemental form. It is written as the charge an atom would have if every bond were purely ionic. In that model, bonding...

ideal gas law

Gas Laws Behind the Ideal Gas Equation

The ideal gas equation brings together the main gas laws used in chemistry. Gases have molecules that are far apart, so their behavior is described with four measurable variables: pressure, volume, number of moles, and temperature. The ideal gas law links these variables with the gas constant, R, which equals 8.314 J·K−1 mol−1. Boyle’s law describes the link between pressure and volume. When temperature and the number of moles stay constant, pressure and volume change in opposite directions.

acid and base concentrations

Acids, Bases, and pH in Titration

Acids, bases, and pH explain how acidic or basic a solution is. An Arrhenius acid releases hydrogen ions when it dissolves in water, while an Arrhenius base releases hydroxide ions. These reactions also create conjugate partners: an acid forms a conjugate base after losing hydrogen, and a base forms a conjugate acid after losing hydroxyl. Every acid has a conjugate base, and every base has a conjugate acid. pH measures the amount of hydrogen ions in a solution. The pH scale runs from 0 to 14...

buffers

Buffer pH and the Common Ion Effect

Buffer solutions help keep pH steady when acids or bases are added. In water, an Arrhenius acid (HA) dissociates into hydrogen ions, H+, and a conjugate base, A-. More hydrogen ions make a solution more acidic and lower its pH. An Arrhenius base (BOH) dissociates into a conjugate acid, B+, and hydroxide ions, OH-. Strong acids and strong bases usually change pH a lot because they react completely in water and raise the amount of H+ or OH-. Buffers reduce those pH changes. A buffer usually...

enthalpy of reaction

Reaction Heat, Hess’s Law, and Calorimetry

Reaction heat is explained through enthalpy, Hess’s law, and calorimetry. These ideas show how heat moves during chemical reactions and how scientists measure it. Thermodynamics is the study of heat energy and other forms of energy, such as work. Its laws are used across science, from biology to physics. The first law says energy is conserved in an isolated system. Energy can change form, such as thermal energy becoming work, but it cannot be created or destroyed. The second law of...

solubility

Solubility in Water and Other Solvents

Solubility describes how much of a solute can dissolve in a specific solvent. It is usually reported as solute mass per solvent volume or as solute mass per solvent mass. For example, sodium chloride has a solubility of 36 g per 100 mL of water at room temperature. If solubility is given by solvent mass, that mass must be converted to volume for later calculations. Temperature changes solubility. Sodium carbonate dissolves at about 7 g per 100 mL of water at 0 °C, 22 g per 100 mL at room...

metal flame emission

Flame Test Metal Color Clues

Flame testing uses a metal sample and a flame to identify a substance by its color. Each element gives off a characteristic light emission in the flame, so the color can help distinguish one element from another. This same idea appears in fireworks, where different metal components create different colors. The color comes from energy absorbed by the metallic component. When a species absorbs energy, that energy can go into translation, vibration, rotation, or electron excitement. Electron...

balmer series

Hydrogen Emission Lines

Hydrogen emission lines show how electrons move between fixed energy levels in the Bohr model. Niels Bohr proposed this model for the hydrogen atom in 1913. In this model, an electron can only occupy certain orbits, and it cannot exist between them. These energy states are labeled with the quantum number n. The ground state is n = 1. Higher values, such as n = 2, 3, 4, and so on, are excited states. An electron changes state only by absorbing or emitting energy equal to the difference between...

beer's law

Absorbance Spectra and Beer-Lambert Analysis

Absorbance spectra and the Beer-Lambert Law show how light can be used to study molecules in solution. When light hits a substance, it may be absorbed, transmitted, or reflected. A substance often interacts with a range of wavelengths, and each wavelength can affect the molecules or atoms in a different way. When a molecule absorbs light, that energy can be used for translation, vibration, rotation, or electron excitement. Electron excitement is especially important in spectroscopy because it...

concentration dependence

Reaction Order and Rate Constants

Chemical kinetics describes the speed of a chemical reaction. The rate depends on the reaction mechanism, the complexity of the reaction, and the number of reactants involved. Reactant concentration also affects how fast a reaction happens. The rate law is the experimental relationship that connects these factors to reaction rate. In the rate law, each reactant contributes through a reaction order. The general form is r = k[A]^m[B]^n for aA + bB + ... → cC. Here, r is the reaction rate, k is...

temperature dependence

Reaction Rate, Arrhenius, and Catalysts

Chemical kinetics explains how fast a reaction happens and why that speed changes. The reaction rate is the speed of a chemical reaction. It is defined as the change in concentration of a reactant or product over time. Reaction speed depends on several factors, including the concentration of the reactants and the temperature of the reaction. Each reactant affects the rate in a specific way. That relationship is described by the rate law. The rate law is an equation that connects the...

galvanic cells

Battery Power from Redox Reactions

Electrochemistry studies how chemical change and electrical energy are linked. In this branch of chemistry, electrons move from one species to another. That movement can either produce current or be driven by an applied current. The main reaction in electrochemistry is the oxidation-reduction, or redox, reaction. A redox reaction has two half-reactions. Oxidation is the loss of electrons, and reduction is the gain of electrons. These changes also shift the oxidation state of each substance. The...

electrolytic cells

Electroplating with Electrolytic Cells

Electrochemistry links electrical energy with chemical change, and electrolytic cells show how electricity can drive a nonspontaneous reaction. In these reactions, electrons move from one species to another. The key chemistry is a redox reaction, or oxidation-reduction reaction, which happens in two half-reactions. Oxidation is the loss of electrons, and reduction is the gain of electrons. The substance that loses electrons is the reducing agent, and the substance that gains electrons is the...

proper lab notebook keeping

Recording a Reproducible Lab Experiment

Accurate lab notebook records are essential in science and organic chemistry labs. Without clear notes, descriptions, quantities, and observations, an experiment cannot be repeated or checked. Good record keeping supports reproducibility, which means other people can follow the same work and get similar results. A laboratory notebook is useful in school labs, research settings, and industry. It can also become a legal record when an idea, process, substance, or technique is patented and...

basic organic chemistry techniques

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...

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

Boiling point and vapor pressure are key physical properties of a liquid. For a pure compound, the boiling point can help identify the substance. In experiments, the boiling point is usually recorded as a range because exact values are hard to measure and may differ by a few degrees from the literature value. Vapor pressure explains why a liquid boils. In a sealed container, some molecules at the liquid surface gain enough energy to escape into the gas phase. At the same time, some gas...

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

Solvent extraction is a common way to separate and isolate a target compound in organic chemistry. In this process, a solute moves from one phase to another so it can be separated from unreacted starting materials or impurities. Extraction is also useful when a product is dissolved in a reaction solvent that is hard to remove by evaporation, such as a solvent with a high boiling point. There are three main types of extraction. In solid-liquid extraction, the solute moves from a solid phase...

simple distillation

Separating Liquids by Boiling Point

Separating liquids by boiling point is the goal of distillation. A miscible mixture contains liquids that mix evenly, and it can be heated so that the more volatile liquid evaporates first. Volatility is a liquid’s tendency to vaporize, and boiling begins when bubbles form in the liquid phase. In a closed container, liquid and vapor can reach equilibrium, which means the rate of vaporization equals the rate of condensation. The pressure from the vapor above the liquid is called vapor pressure.

steam distillation

Steam Distillation and Low-Boiling Separation

Steam distillation is a separation method for temperature-sensitive organic compounds. It works best when the organic compound is immiscible in water, meaning the two liquids do not mix. The method helps remove the organic molecule from a non-volatile contaminant without using the higher temperatures needed for many other separations. In steam distillation, the immiscible mixture is heated until both water and the volatile organic compound distill together. The vapor rises to a condenser,...

thin-layer chromatography

TLC Separation by Polarity

Thin-layer chromatography (TLC) separates compounds in a mixture by polarity. It uses the same basic parts as other chromatography methods: a stationary phase, a mobile phase, and the solute. In TLC, the stationary phase is a thin coating on a plate instead of material packed into a column. The stationary phase in most TLC systems is polar silica gel, a form of silicon dioxide. Its surface has OH groups that can form hydrogen bonds. The sample is first spotted on a pencil start line with a...

column chromatography

Separating Mixtures by Polarity

Column chromatography separates compounds in an organic chemistry lab by using differences in physical properties. It is especially useful for microscale separations when less than 10 grams of material is available for analysis. The method can separate a mixture based on solubility, polarity, hydrophobicity, size, and charge. Any chromatography system has three main parts: the stationary phase, the mobile phase, and the sample mixture. In column chromatography, the stationary phase is usually...

hydrolysis of an ester

Soap Formation from Triglycerides

Triglycerides are lipids made of a glycerol backbone linked to three fatty acids. They are common in vegetable oils and animal fats. Plant lipids are the basis of vegetable oils, while animal lipids are used as lard or general sources of fats. A fatty acid has a long carbon chain, usually between 12 and 20 carbons, with a weak organic acid at one end. Some fatty acids contain double bonds. These are unsaturated fats. The double bond usually gives the chain a bent, cis shape. As a result,...

synthesis of luminol

Luminol Chemiluminescence in Forensics

Luminol chemiluminescence shows how a chemical reaction can produce light and help with blood detection. Chemical reactions may be endothermic or exothermic, depending on whether they absorb or release heat as reactants become products. The enthalpy of a reaction is the energy difference between reactants and products, or ΔH. A positive ΔH means the reaction is endothermic. A negative ΔH means it is exothermic. Many reactions do not happen in a single step. They can pass through intermediates...

esterification

Ester Formation and Everyday Fragrances

Esters are organic compounds with a carbonyl group attached to an oxygen that connects to another alkyl or aryl group. Their general formula is RCOOR'. They are often made by reacting a carboxylic acid with an alcohol in an esterification reaction. In this process, the hydroxyl group of the acid is replaced by an alkyl or aryl group. Many simple esters have familiar fruit and flower smells because their structures are small and less complex. Formic acid and methanol can combine to form methyl...

identification of unknown aldehydes and ketones

identification-of-unknown-aldehydes-and-ketones

Carbonyl Tests for Aldehydes and Ketones

Aldehydes and ketones are carbonyl compounds, which means they contain a C=O functional group. A ketone has two alkyl or aryl groups attached to the carbonyl carbon. Acetone is the simplest ketone, with two methyl groups. An aldehyde is similar, but it has at least one hydrogen attached to the carbonyl carbon. Formaldehyde is the simplest aldehyde, and acetaldehyde has one hydrogen and one methyl group. The carbonyl carbon in both aldehydes and ketones is electrophilic because the oxygen atom...

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

入門化学ラボコースの指導者と学生のための、包括的でカリキュラムに焦点を当てたビデオ。

https://cloudfront.jove.com/files/banners/scicat/labbio.jpg

Learn how solvent extraction separates mixtures in organic chemistry, including liquid-liquid extraction, separatory funnels, partition coefficients, and acid-base extraction.

Separating Mixtures with Solvent Extraction | JoVE K12

抽出 を教える準備を、この 3 分間の教員向けガイドで行いましょう。JoVE Lab Manual の Chemistry ラボの主要な準備手順を解説します。

Chemistry の 抽出 教員準備 - 8.0K+ 回の視聴 | JoVE Lab Manual

この 19 分間の学生プロトコル動画で、抽出 の手順をステップごとに学びましょう。JoVE Lab Manual の Chemistry コレクションの一部です。

Chemistry の 抽出 学生プロトコル - 67K+ 回の視聴 | JoVE Lab Manual

Separating Mixtures with Solvent Extraction

Description

Transcript