| 单词 | phenolphthalein |
| 例句 | Substances such as phenolphthalein, which can be used to determine the pH of a solution, are called acid-base indicators. Chemistry 2019-02-14T00:00:00Z Still other dietary supplement products for weight loss contained the laxative phenolphthalein or prescription diuretics. Beware of natural supplements for sex gain and weight loss 2018-12-17T05:00:00Z A chemical called phenolphthalein -- not approved by FDA -- was found in a Chinese product called Zi Xiu Tang Beauty Face & Figure Capsule. FDA Finds Potentially Harmful Ingredients in Certain Supplements 2016-08-11T04:00:00Z Some of the supplements also contain another chemical used previously in over-the-counter laxative products, a dye called phenolphthalein. Bee Pollen Supplements Stung By FDA, Contain Real Drugs 2014-12-01T05:00:00Z Because of the large quantity of water present, phenolphthalein is unsatisfactory, as dissociation of the soap may show a pink indication in spite of the fact the mass is on the acid side. Soap-Making Manual A Practical Handbook on the Raw Materials, Their Manipulation, Analysis and Control in the Modern Soap Plant. Any of the three indicators will exhibit a reasonably sharp color change at the equivalence point of the strong acid titration, but only phenolphthalein is suitable for use in the weak acid titration. Chemistry 2019-02-14T00:00:00Z Titrate the distillate with N/10 alkali, using phenolphthalein as an indicator. All About Coffee The test is best made by the use of the well known alkaline tablet which is composed of a solid alkali, and the indicator, phenolphthalein. Outlines of Dairy Bacteriology, 8th edition A Concise Manual for the Use of Students in Dairying Titrate against n/10 sodic hydrate solution using phenolphthalein as the indicator. The Elements of Bacteriological Technique A Laboratory Guide for Medical, Dental, and Technical Students. Second Edition Rewritten and Enlarged. The stock thus obtained should be fairly white, depending upon the grade of tallow used and slightly alkaline to an alcoholic phenolphthalein solution. Soap-Making Manual A Practical Handbook on the Raw Materials, Their Manipulation, Analysis and Control in the Modern Soap Plant. Note:—The potassium oxalate and the formalin must both be neutral to phenolphthalein. The Starvation Treatment of Diabetes Transfer the precipitate and filter to the beaker, or precipitating vessel, dissolve the precipitate in a small excess of the standard alkali, add a few drops of phenolphthalein solution, and titrate with the standard acid. All About Coffee The chemical reaction of cheese is normally acid to phenolphthalein, although there is generally no free acid, as shown by Congo red, the lactic acid being converted into salts as fast as formed. Outlines of Dairy Bacteriology, 8th edition A Concise Manual for the Use of Students in Dairying Dibasic sodium phosphate which is formed during the process of neutralisation is a salt which reacts alkaline to litmus, but neutral to phenolphthalein. The Elements of Bacteriological Technique A Laboratory Guide for Medical, Dental, and Technical Students. Second Edition Rewritten and Enlarged. Samples are taken at this time, cooled and tested by alcoholic phenolphthalein solution. Soap-Making Manual A Practical Handbook on the Raw Materials, Their Manipulation, Analysis and Control in the Modern Soap Plant. To 25 c.c. of urine add 5 c.c. of a saturated solution of potassium oxalate and 2 to 3 drops of phenolphthalein. The Starvation Treatment of Diabetes Into a small beaker pour 6 cc. of vinegar and 10 cc. of water and a few drops of phenolphthalein indicator. Human Foods and Their Nutritive Value A substance called phenolphthalein, a coal-tar product, is a very delicate indicator; it is more sensitive to acids than litmus is. The Chemistry of Hat Manufacturing Lectures Delivered Before the Hat Manufacturers' Association The reaction of the fresh potato is strongly acid to phenolphthalein. The Elements of Bacteriological Technique A Laboratory Guide for Medical, Dental, and Technical Students. Second Edition Rewritten and Enlarged. The glycerine water or first lye is run to the treatment tank, the fat skimmed off and neutralized with lime until it shows pink with phenolphthalein, after having been thoroughly boiled with steam. Soap-Making Manual A Practical Handbook on the Raw Materials, Their Manipulation, Analysis and Control in the Modern Soap Plant. The alcohol must be tested as to its reaction before using it, and carefully neutralized with the acid of phenolphthalein. Scientific American Supplement, No. 443, June 28, 1884 After letting stand 30 minutes, filter and then titrate 50 cc. of the filtrate against standard KOH solution, using phenolphthalein as indicator, 1 cc. of the alkali equals 0.009 gms. lactic acid. Human Foods and Their Nutritive Value However, phenolphthalein, though reacting alkaline with monocarbonate of soda, indicates the acidity of the bicarbonate of soda, a thing which, as I have just said, litmus will not do. The Chemistry of Hat Manufacturing Lectures Delivered Before the Hat Manufacturers' Association Mould growth, on the other hand, is most vigourous in media that are strongly acid to phenolphthalein. The Elements of Bacteriological Technique A Laboratory Guide for Medical, Dental, and Technical Students. Second Edition Rewritten and Enlarged. Test a freshly cut surface of the soap with a few drops of an alcoholic phenolphthalein solution. Soap-Making Manual A Practical Handbook on the Raw Materials, Their Manipulation, Analysis and Control in the Modern Soap Plant. A drop of phenolphthalein is now added, a little water, and the acidity determined by titration with deci-normal baryta solution, and the baryta solution taken calculated as oleic acid. Nitro-Explosives: A Practical Treatise A !phenolphthalein solution! is prepared by dissolving 1 gram of the pure compound in 100 cc. of 95 per cent alcohol. An Introductory Course of Quantitative Chemical Analysis With Explanatory Notes We will take two jars containing solution of monocarbonate of soda, and in the first we will put some phenolphthalein solution, and in the second, some litmus tincture. The Chemistry of Hat Manufacturing Lectures Delivered Before the Hat Manufacturers' Association Litmus is insensitive to many weak organic acids the presence of which is readily indicated by phenolphthalein. The Elements of Bacteriological Technique A Laboratory Guide for Medical, Dental, and Technical Students. Second Edition Rewritten and Enlarged. The solution is then neutralized with alcoholic sodium hydroxide, using phenolphthalein as an indicator. Soap-Making Manual A Practical Handbook on the Raw Materials, Their Manipulation, Analysis and Control in the Modern Soap Plant. After the addition of phenolphthalein the acid is titrated, and the amount used calculated into oleic acid. Nitro-Explosives: A Practical Treatise The indicators in most common use for acid and alkali titrations are methyl orange, litmus, and phenolphthalein. An Introductory Course of Quantitative Chemical Analysis With Explanatory Notes We have, therefore, in bicarbonate of soda a salt which behaves as an acid to phenolphthalein and as an alkali to litmus. The Chemistry of Hat Manufacturing Lectures Delivered Before the Hat Manufacturers' Association Sample of filtered meat extract or nutrient gelatine to which phenolphthalein has been added. The Elements of Bacteriological Technique A Laboratory Guide for Medical, Dental, and Technical Students. Second Edition Rewritten and Enlarged. Add phenolphthalein to the filtrate and titrate with N/10 acid and calculate the per cent. of free alkali as sodium or potassium hydroxide. Soap-Making Manual A Practical Handbook on the Raw Materials, Their Manipulation, Analysis and Control in the Modern Soap Plant. The materials needed are: One glass pitcher, filled with water, four glass tumblers, an acid, an alkali and some phenolphthalein solution which can be obtained from your local druggist. The Boy Mechanic: Volume 1 700 Things for Boys to Do In the following discussion of the principles underlying the behavior of the indicators as a class, methyl orange and phenolphthalein will be taken as types. An Introductory Course of Quantitative Chemical Analysis With Explanatory Notes It is advisable to titrate the crude anthranilic acid with standard alkali and phenolphthalein before starting the experiment. Organic Syntheses As a general rule growth is most active in media which react slightly acid to phenolphthalein—that is, neutral or faintly alkaline to litmus. The Elements of Bacteriological Technique A Laboratory Guide for Medical, Dental, and Technical Students. Second Edition Rewritten and Enlarged. When dark colored oils or fats are being titrated it is often difficult to obtain a good end point with phenolphthalein. Soap-Making Manual A Practical Handbook on the Raw Materials, Their Manipulation, Analysis and Control in the Modern Soap Plant. If borax is present the carbon dioxide is boiled off after neutralizing exactly to methyl orange; cool, add mannite and phenolphthalein and titrate the boric acid with standard alkali. Soap-Making Manual A Practical Handbook on the Raw Materials, Their Manipulation, Analysis and Control in the Modern Soap Plant. Of the common indicators methyl orange is the most sensitive toward alkalies and phenolphthalein toward acids; the others occupy intermediate positions. An Introductory Course of Quantitative Chemical Analysis With Explanatory Notes A few drops of phenolphthalein solution are added and sulfur dioxide passed in, first until an acid reaction is indicated and then for two or three minutes longer. Organic Syntheses Measure 25 c.c. of the meat extract into one of the beakers, wash out the measure with boiling water, and add the phenolphthalein as in the first estimation. The Elements of Bacteriological Technique A Laboratory Guide for Medical, Dental, and Technical Students. Second Edition Rewritten and Enlarged. The mixture of fat and neutralized alcohol is then heated to boiling and titrated with tenth normal alkali solution, using phenolphthalein as an indicator. Soap-Making Manual A Practical Handbook on the Raw Materials, Their Manipulation, Analysis and Control in the Modern Soap Plant. It is worthy of note that in the presence of much free anhydride a compound is formed with phenolphthalein, soluble in alkali and acetic acid, but insoluble in neutral solutions. Soap-Making Manual A Practical Handbook on the Raw Materials, Their Manipulation, Analysis and Control in the Modern Soap Plant. It may be employed with some of the stronger organic acids, but the use of phenolphthalein is to be preferred. An Introductory Course of Quantitative Chemical Analysis With Explanatory Notes On account of the strong alkaline solution, the original color produced by the phenolphthalein is very faint, but this slowly increases until it becomes deep just before the acid point is reached. Organic Syntheses Cool and titrate with the N/2 hydrochloric acid, using phenolphthalein as an indicator. Soap-Making Manual A Practical Handbook on the Raw Materials, Their Manipulation, Analysis and Control in the Modern Soap Plant. Dissolve the residue in neutral alcohol and titrate with standard alkali using phenolphthalein as an indicator. Soap-Making Manual A Practical Handbook on the Raw Materials, Their Manipulation, Analysis and Control in the Modern Soap Plant. When saponification has taken place, the mass begins to clear and a sample taken out with a paddle and cooled should show a slight pink with a 1 per cent. alcoholic phenolphthalein solution. Soap-Making Manual A Practical Handbook on the Raw Materials, Their Manipulation, Analysis and Control in the Modern Soap Plant. The comparison of the acid and alkali solutions was made, using methyl orange as an indicator, while the titration of the oxalic acid is made with the use of phenolphthalein. An Introductory Course of Quantitative Chemical Analysis With Explanatory Notes It is best to remove a small sample of the liquid from time to time, dilute with three or four volumes of water and add a drop more of phenolphthalein. Organic Syntheses From the following data identify them: Sample I. On adding phenolphthalein to a solution of the substance, it gave no color to the solution. An Introductory Course of Quantitative Chemical Analysis With Explanatory Notes Let stand with occasional shaking, for several hours, to permit the hydrolysis of all the anhydride; then dilute to about 200 cc., add phenolphthalein and titrate with N/1 NaOH. Soap-Making Manual A Practical Handbook on the Raw Materials, Their Manipulation, Analysis and Control in the Modern Soap Plant. On titrating with standard acid, it required 15.26 cc. for a change in color, using phenolphthalein, and 17.90 cc. additional, using methyl orange as an indicator. An Introductory Course of Quantitative Chemical Analysis With Explanatory Notes In titrating solutions of alkali carbonates in the presence of phenolphthalein, the color change takes place when the carbonate has been converted to bicarbonate. An Introductory Course of Quantitative Chemical Analysis With Explanatory Notes The sample was titrated with hydrochloric acid until the pink of phenolphthalein disappeared, and on the addition of methyl orange the solution was colored pink. An Introductory Course of Quantitative Chemical Analysis With Explanatory Notes On titrating with hydrochloric acid, using phenolphthalein, 15.00 cc. were required. An Introductory Course of Quantitative Chemical Analysis With Explanatory Notes Add 50 to 100 cc. hot, neutral alcohol, and titrate with N/2, N/4 or N/10 sodium hydroxide depending on the fatty acid content, using phenolphthalein as indicator. Soap-Making Manual A Practical Handbook on the Raw Materials, Their Manipulation, Analysis and Control in the Modern Soap Plant. Two hundred cubic centimeters of this filtrate require 29.62 cc. of 0.1062 N hydrochloric acid for neutralization, using phenolphthalein as an indicator. An Introductory Course of Quantitative Chemical Analysis With Explanatory Notes It is titrated with 0.30 N hydrochloric acid, using phenolphthalein in cold solution as an indicator and becomes colorless after the addition of 48.16 cc. An Introductory Course of Quantitative Chemical Analysis With Explanatory Notes Owing to the carelessness of the analyst's assistant, the sodium hydroxide solution was used with phenolphthalein as an indicator in cold solution in making the analyses. An Introductory Course of Quantitative Chemical Analysis With Explanatory Notes |
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