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how to separate butyric acid and hexane. However, you may visit "Cookie Settings" to provide a controlled consent. A third method is to add a bit more solvent to the funnel to somewhat dilute one of the layers, or to add a different solvent to alter the index of refraction. flowchart. \(\ce{RNH_2}\)), and neutral components to be purified through a series of extractions, as summarized in Figure 4.59 (which uses an organic solvent less dense than water). This strategy can be extended to other examples. After allowing the layers to separate in the funnel, drain the bottom organic layer into a clean Erlenmeyer flask (and label the flask, e.g. deprotonated. Cyclohexane would remain in the organic layer as it has no affinity for the aqueous phase, nor can react with \(\ce{NaOH}\) in any way. Be sure that the Teflon stopcock is moderately tight so that it can still easily turn, but is not so loose that liquid can seep around the joint. The solubility properties of carboxylic acids are substantially different than their corresponding carboxylate salts. This cookie is set by GDPR Cookie Consent plugin. Two things I don't know yet from you: flow through the column in cm/sec and flow in ml/min. As previously discussed, carboxylic acids can be extracted from an organic layer into an aqueous layer by shaking them with basic solutions, which converts them into their more water-soluble salts. Pour a quantity of the extractive solvent into the separatory funnel, as indicated by the procedure (Figure 4.24c). Repeat for pH levels of 5.00 and 7.00. Close the stopcock and mix the solutions a bit more vigorously, periodically stopping to vent the system. Cyclohexane would remain in the organic layer as it has no affinity for the aqueous phase, nor can react with \(\ce{NaOH}\) in any way. There may be soap-like compounds or other emulsifying agents present that dissolve some of the components in one another. The benzoic acid is also a strong acid, therefore it will dissolve in sodium bicarbonate solution to form salt and water by liberating carbon dioxide.. In certain embodiments, the invention provides a method of processing a protein comprising dissolving a protein in a solution, optionally removing any insoluble materials from the solution, and spraying the solution under an applied pressure. How do you separate benzoic acid and salt? If fine crystals form (which are quite common), they will clog the filter paper and interfere with adequate drainage. In this manner, a mixture of benzoic acid and cyclohexane can be separated (Figure 4.54b). Hold the conical vial or tapered tube in the same hand as a container for the bottom layer (label it). Transfer this ether also to the separatory funnel. It is also possible that a middle third layer is an emulsion, where the two layers are not fully separated. Perform a single extraction using approximately \(25 \: \text{mL}\) of dichloromethane (\(\ce{CH_2Cl_2}\), an exact amount is not necessary), as described previously, with the following differences: As \(\ce{CH_2Cl_2}\) is prone to emulsions, invert the funnel and shake. Check out a sample Q&A here. To the aqueous layer remaining in the funnel, add a. If large quantities of acid are present such that acidification would require too great a volume of \(2 \: \text{M} \: \ce{HCl} \left( aq \right)\), concentrated \(\ce{HCl} \left( aq \right)\) may be instead added dropwise. 28 0 obj We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. 0000002970 00000 n After collecting the hexane phase (1 ml), an additional aliquot of 1 ml of hexane is added to the mixture, vortex-mixed and centrifuged. The LibreTexts libraries arePowered by NICE CXone Expertand are supported by the Department of Education Open Textbook Pilot Project, the UC Davis Office of the Provost, the UC Davis Library, the California State University Affordable Learning Solutions Program, and Merlot. Pressure may build up inside the separatory funnel when solutions are mixed, so immediately after swirling, and with the funnel still inverted, ". Remember that a centrifuge needs to be balanced or it may wobble off the benchtop. Eclipse Business Media Ltd, Regd in England, No. The carboxylic acids with 5 to 10 carbon atoms all have "goaty" odors (explaining the odor of Limburger cheese). This problem has been solved! Hydrochloric acid is generally used to protonate amines. Methyl ester of butyric acid could not be analysed by splitless without be overlapped to the solvent, even if very low boiling solvents such as pentane or petrol ether are used. 0000006601 00000 n First (better) : use on-column injection and pentane as solvent. A small amount of insoluble film between two layers is not uncommon during an extraction. "bottom organic layer"). Expert Answer. Subscribe to our eNewsletter with daily, weekly or monthly updates: Food, Environmental, (Bio)Pharmaceutical, Bioclinical, Liquid Chromatography, Gas Chromatography and Mass Spectrometry. Extracting Carboxylic Acids vs. Phenols. An aqueous solution of the acid or base is added, and the pH of the aqueous phase is adjusted to bring the compound of interest into its required form. 0000053591 00000 n Additional light sometimes allows you to see the interface. Usually, the mixture is dissolved in a suitable solvent such as dichloromethane or diethyl ether (ether), and poured into a separating funnel. Drain the rest of the bottom layer, stopping when the interface is inside the stopcock. How would you separate a mixture of p toluic acid and p toluidine? H bonding most significant; of low molecular mass. What does it mean to nominate candidates? If the top layer is the desired layer, remove it from the conical vial using a fresh pipette into a clean container. The cookies is used to store the user consent for the cookies in the category "Necessary". 0000005145 00000 n Extraction is the recovery of a substance from a mixture by bringing it . Don't throw away either layer until you are sure you've accomplished the goal of the extraction. Additionally, the sodium bicarbonate neutralizes the catalytic acid in this reaction. 0000007038 00000 n Expert Solution. The boiling point of cyclohexane is _______C and the boiling point of toluene is _________C. When acid is added to an aqueous solution that contains the salt of a deprotonated organic acid, the organic acid is re-protonated. In this section are stepwise instructions on how to extract an aqueous solution with an organic solvent that is denser than water (the organic layer will be on the bottom). A separatory funnel is commonly used to perform an acid . Get more out of your subscription* Access to over 100 million course-specific study resources; 24/7 help from Expert Tutors on 140+ subjects; Full access to over 1 million Textbook Solutions Transcribed Image Text: Draw a flowchart to show how you separate a mixture of butyric acid and hexane. An occasional reason that only one layer forms in a separatory funnel is if there are large quantities of compounds present that dissolve in both solvents, for example if large amounts of ethanol are present, which dissolve well in both aqueous and organic solvents. Salts and esters of butyric acid are known . Butyric acid can in principle be extracted by phase separation ('salting out') by adding CaCl 2 or KCl up to saturation. Allow the solution to sit for a period of time (even until the next lab period) if possible. In this section are described differences between general extraction procedures and the process as summarized in Figure 4.59. If this happens, there are several methods that might help you see the interface. 06513189, Woodview, Bull Lane Industrial Estate, Sudbury, CO10 0FD, United Kingdom, T +44 (0)161 818 7434 info@sepscience.com, Copyright 1999 - 2022. Place the separatory funnel in a ring clamp attached to a ring stand or latticework. Butyric acid makes up about half of these SCFAs. In this manner, a mixture of benzoic acid and cyclohexane can be separated (Figure 4.54b). Solution The major components of the resulting PEG-rich phase were butyric acid, acetic acid and butanol. This "salting out" effect is very efficient to separate butyric acid from the simulated butyrate fermentation broth, which consists of butyric acid and acetic acid with concentration ratio of 4?1, so that the final ratio of butyric acid/acetic acid in the upper phase is improved to 9.87. boiling points higher than hydrocarbons of similar size; dispersion forces become significant; as chain length increases. The extraction efficiency of using pure n-hexane to separate butyric acid from water, for example, is only 6.0%, while adding just a small amount of hexanoic acid (to result in a binary solvent mixture with a n-hexane concentration of 95%), will cause a dramatic jump in extraction efficiency to 51.4%. Alternatively, manually mix the layers using a pipette. This cookie is set by GDPR Cookie Consent plugin. Why do you wash the dichloromethane solution of your reductive amination product with sodium bicarbonate, rather than dilute aqueous HCl? A centrifuge hastens the process of letting an emulsion settle on its own. The color (methyl red), is extracted from the aqueous layer (bottom) into the ethyl acetate layer (top). Advertisement cookies are used to provide visitors with relevant ads and marketing campaigns. In this flask, there should be roughly \(50 \: \text{mL}\) of dichloromethane from the two extractions. The acid is of considerable commercial importance as a raw material in the . A TLC plate of the reaction mixture at 1 hour of reflux showed residual unreacted carboxylic acid (Figure 4.56c), which is not uncommon due to the energetics of the reaction. Acidogenic stage is the first step that occurs during fermentation, which leads to the formation of butyric acid (butyrate) and acetic acid (acetate) along with carbon dioxide and hydrogen. "bottom layer"). The pictures in this section show the extraction of \(2 \: \text{mL}\) of a mildly acidic aqueous solution containing a single drop of methyl red solution into \(2 \: \text{mL}\) of ethyl acetate. You mean to extract my fatty acid metyl esters with petroleum ether instead? An acid-base extraction can be used to extract carboxylic acids from the organic layer into the aqueous layer. Finally the benzoic acid will be precipitated by adding strong acid to the carboxylate salt solution. Separation of Butyric Acid and Hexane OH butyric hexane acid 1. The hydroxide, these electrons here, would deprotonate the phenol, giving you again the phenolate anion, along with the hexane in your organic layer. The compound phenol is considered as a weak acid. Then wash the funnel with soap and water at your benchtop. Gently invert the funnel (Figure 4.26b), and swirl the mixture a little. \[\begin{array}{ccccccccc} \ce{PhCO_2H} \left( aq \right) & + & \ce{NaOH} \left( aq \right) & \rightarrow & \ce{H_2O} \left( l \right) & + & \ce{PhCO_2Na} \left( aq \right) & & \left( \text{or } \ce{PhCO_2^-} \ce{Na^+} \right) \\ \text{Carboxylic acid} & & & & & & \text{Carboxylate salt} & & \end{array}\]. An acidic solute, HA, has a K a of \(1.00 \times 10^{-5}\) and a K D between water and hexane of 3.00. trailer As has been discussed previously, the acid-base properties of compounds can be utilized to selectively extract certain compounds from mixtures. 0000040333 00000 n Question. After you dispense the different alcohols into the tubes, and immediately before you add the acid, smell the odor of the alcohol in the tube by wafting the vapors to your nose (your . if using \(100 \: \text{mL}\) aqueous solution, extract with \(33 \: \text{mL}\) organic solvent each time). This page titled 4.6: Step-by-Step Procedures For Extractions is shared under a CC BY-NC-ND license and was authored, remixed, and/or curated by Lisa Nichols via source content that was edited to the style and standards of the LibreTexts platform; a detailed edit history is available upon request. A similar reaction occurs: \[\begin{array}{ccccccccccc} \ce{PhCO_2H} \left( aq \right) & + & \ce{NaHCO_3} \left( aq \right) & \rightarrow & \ce{PhCO_2Na} \left( aq \right) & + & \ce{H_2CO_3} \left( aq \right) & \rightleftharpoons & \ce{H_2O} \left( l \right) & + & \ce{CO_2} \left( g \right) \\ \text{Benzoic acid} & & & & \text{Sodium benzoate} & & & & & & \end{array}\]. <> 2. Lower concentrations of \(\ce{HCl} \left( aq \right)\) are less hazardous, but increasing the volume of the aqueous layer by a large amount would affect the efficiency of subsequent extractions and filtering steps. centrifuge tube). If only a small amount of solid is seen compared to the theoretical quantity, it is likely the compound is quite water-soluble, and filtration would lead to low recovery. The invention relates to non-woven protein fibers and to methods for forming and producing the same. If the funnel is shaken with more vigor it will likely settle into two layers (Figure 4.31b). When organic solvent is added to an organic layer in the separatory funnel, the result is only one layer. After acidification, two routs may be taken, depending on if the acidic component is solid or liquid. You would dissolve the mixture in an organic solvent and then perform as many extractions as are necessary with an NaHCO3 aqueous solution in order to extract the butyric acid. It is assumed that readers conducting this type of experiment are familiar with performing single and multiple extractions. The solubility properties of carboxylic acids are substantially different than their corresponding carboxylate salts. Acid-Base Extraction: Acid-base extraction is a technique that is widely used to separate organic compounds. After filtration, the broth was added into PEG at different concentrations to form the aqueous two-phase solution. Further drain the bottom layer, stopping when the interface just enters the stopcock chamber (Figure 4.27d). Since it is most common to combine the organic layers in multiple extractions, the bottom organic layer can be drained from the separatory funnel into the same flask that was used for the organic layer in the first extraction (that may have been labeled "bottom organic layer"). Want to see the full answer? Q: Draw a flowchart to show how you separate a mixture of butyric acid and hexane. Emulsions can happen for several reasons: Emulsions can be very difficult to rectify, and it's best if they are avoided in the first place by shaking solutions that are prone to emulsions (e.g. (4.8.3) PhNH 2 ( a q) + HCl ( a q) PhNH 3 Cl ( a q) ( or PhNH 3 + Cl ) Basic amine . Theory and Background: Distillation refers to the laboratory technique used to separate mixtures by heating them until evaporation, and then condensing said . You will use 2-mL portions of ethyl alcohol, isopropyl alcohol, and t -butyl alcohol in separate test tubes. What is the pH of butyric acid? Return the rest of the top layer to the conical vial. Gently mix the two solutions using one of the following methods: Secure a cap firmly on the vial (Figure 4.36c+d) then invert and shake the tube for 10-20 seconds (Figure 4.35). Due to low boiling point of methyl ester of butyric acid no focusing is possible into the top of GC column and peak is then very broad and mixed with solvent front. 0000004382 00000 n It's also found in lower amounts in some foods. 0 The Salt can then be recovered by boiling the water until there is none left. Draw a flowchart to show how you separate a mixture of butyric acid and hexane. In this way, they can be extracted from an organic layer into an aqueous layer. One method is to add \(\ce{NaCl}\) or \(\ce{NH_4Cl}\) to the separatory funnel, which dissolves in the aqueous layer and decreases the ability of organic compounds to dissolve in water ("salting out"). The acidic compound, butyric acid, will then be extracted using a NaHCO3 aqueous solution in one (or more) extractions. The most common reason for having only one layer in a separatory funnel when there should be two (as in when the procedure tells you to "separate the layers"), is to have made a mistake. In this section are described differences between general extraction procedures and the process as summarized in Figure 4.59. 0000001162 00000 n Keep the funnel for some time so as to allow the layers to separate. Withdraw a pipette-full of the bottom layer from the vial, and then vigorously expunge the solution through the top layer (Figure 4.36e). Legal. 0000003450 00000 n longer chained butanoic acid; cheesy odour boiling point. endobj Invert the funnel and shake gently for 10-20 seconds. In this flask, there should be roughly \(50 \: \text{mL}\) of diethyl ether from the two extractions. Before that I need to get a good extraction of milk fatty acids and analyse its profile with GC-FID. Hence, separating a mixture of a carboxylic acid and a phenol would be done using bicarbonate ion since only the carboxylic acid is converted into its conjugate base by bicarbonate. Before pouring anything into a separatory funnel, be sure that the stopcock is in the "closed" position, where the stopcock is horizontal (Figure 4.24a). As an example, the instructions are written to extract an aqueous solution three times using \(25 \: \text{mL} \: \ce{CH_2Cl_2}\) each time (\(3 \times 25 \: \text{mL} \: \ce{CH_2Cl_2}\), Figure 4.30). And now we've learned how to do extractions. In other embodiments, the protein can be derived . You would dissolve the mixture in an organic solvent and then perform as many extractions as are necessary with an NaHCO3 aqueous solution in order to extract the butyric acid. How would you separate butyric acid and hexane? These cookies track visitors across websites and collect information to provide customized ads. If large quantities of acid are present such that acidification would require too great a volume of \(2 \: \text{M} \: \ce{HCl} \left( aq \right)\), concentrated \(\ce{HCl} \left( aq \right)\) may be instead added dropwise. Necessary cookies are absolutely essential for the website to function properly. { "4.01:_Prelude_to_Extraction" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "4.02:_Overview_of_Extraction" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "4.03:_Uses_of_Extraction" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "4.04:_Which_Layer_is_Which" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "4.05:_Extraction_Theory" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "4.06:_Step-by-Step_Procedures_For_Extractions" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "4.07:_Reaction_Work-Ups" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "4.08:_Acid-Base_Extraction" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()" }, { "00:_Front_Matter" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "01:_General_Techniques" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "02:_Chromatography" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "03:_Crystallization" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "04:_Extraction" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "05:_Distillation" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "06:_Miscellaneous_Techniques" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "07:_Technique_Summaries" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "08:_About_the_Author_-_Lisa_Nichols" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "zz:_Back_Matter" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()" }, 4.6: Step-by-Step Procedures For Extractions, [ "article:topic", "Liquid-Liquid Extraction", "authorname:nicholsl", "methyl red", "Single Extraction", "Multiple Extractions", "Microscale Extractions", "showtoc:no", "license:ccbyncnd", "transcluded:yes", "source[1]-chem-93534", "source@https://organiclabtechniques.weebly.com/" ], https://chem.libretexts.org/@app/auth/3/login?returnto=https%3A%2F%2Fchem.libretexts.org%2FCourses%2FSUNY_Oneonta%2FChem_221%253A_Organic_Chemistry_I_(Bennett)%2F2%253ALab_Textbook_(Nichols)%2F04%253A_Extraction%2F4.06%253A_Step-by-Step_Procedures_For_Extractions, \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}}}\) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash{#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\), Prepare the Setup (for single extraction), Add the Solutions (for single extraction), Mix the Solutions (for single extraction), Separate the Layers (for single extraction), There is Insoluble Material at the Interface, The Layers Don't Separate Well (An Emulsion Formed), Mix the Solutions (for microscale extraction), Separate the Layers (for microscale extraction), source@https://organiclabtechniques.weebly.com/, status page at https://status.libretexts.org. In the case of 1-(14)C-labelled butyrate, the appearance of radioactivity in the blood of injected mice is rapid and some of it is maintained for relatively long periods in different organs, mainly the liver.However, no precision can be given about the structure of . Performance cookies are used to understand and analyze the key performance indexes of the website which helps in delivering a better user experience for the visitors. In this experiment an acid-base extraction will be used to separate a mixture containing about equal parts of an unknown carboxylic acid and an unknown neutral compound. If another extraction is to be done, return the bottom layer to the conical vial, add fresh solvent and repeat the extraction and separation. Close the stopcock on the separatory funnel and position an Erlenmeyer flask beneath the setup, in case it drips. One is to hold the separatory funnel up to the light, or to shine a flashlight onto the glass (Figure 4.32b). A minor film is not something to worry about because if a small amount does make it into the organic layer, a subsequent drying and filtration step will often remove it. Return the separatory funnel to the ring clamp, and allow the layers to separate. Do not drain the top aqueous layer from the funnel. As previously discussed, carboxylic acids can be extracted from an organic layer into an aqueous layer by shaking them with basic solutions, which converts them into their more water-soluble salts. A pharmacokinetics study was performed by injecting butyric acid as sodium or arginine salts for possible antitumor therapies. Into the separatory funnel pour the liquid to be extracted using a funnel: this prevents liquid from getting on the ground glass joint which can cause it to stick. 4 To calculate the yield, productivity and concentration of the Sodium salicylate is roughly 350 times more soluble in water than salicylic acid due to its ionic character (Figure 4.55), and it is rather insoluble in organic solvents such as diethyl ether. Get the answers you need, now! Legal. After partition of the solution, PEG and most butyric acid, acetic acid and butanol were contained in the PEG-rich phase. Basic compounds such as amines can be extracted from organic solutions by shaking them with acidic solutions to convert them into more water-soluble salts. If an emulsion is formed because the two layers have similar densities, try to alter the density of each layer to make them more different. The residual carboxylic acid can be removed from the desired ester product using an acid-base extraction in a separatory funnel. In this situation, the best approach is to remove the troublesome compound (i.e. To demonstrate, benzoic acid was refluxed in ethanol along with concentrated sulfuric acid in order to form ethyl benzoate (Figure 4.56a+b). The precipitate is collected by filtration then recrystallized freom hot water. These cookies will be stored in your browser only with your consent. Lower concentrations of \(\ce{HCl} \left( aq \right)\) are less hazardous, but increasing the volume of the aqueous layer by a large amount would affect the efficiency of subsequent extractions and filtering steps. The LibreTexts libraries arePowered by NICE CXone Expertand are supported by the Department of Education Open Textbook Pilot Project, the UC Davis Office of the Provost, the UC Davis Library, the California State University Affordable Learning Solutions Program, and Merlot. To isolate, wash with brine (\(\times 1\)) if using diethyl ether or ethyl acetate, dry with a drying agent, and remove the solvent via rotary evaporator to leave the pure neutral component. As was discussed in the previous section, \(\ce{NaOH}\) can be used to convert a carboxylic acid into its more water-soluble ionic carboxylate form. If the correct layer is added to the funnel, everything will work out as planned.