"shown that a speaker's choice of frame can reflect their knowledge of the environment, and that listeners can be sensitive to this information. Is the glass half empty or half full? ""Is the glass half empty or half full?"" is a common expression, a proverbial phrase, generally used rhetorically to indicate that a particular situation could be a cause for optimism (half full) or pessimism (half empty), or as a general litmus test to simply determine an individual's worldview. The purpose of the question is to demonstrate that the situation may be seen in different ways depending on one's point"
"Alkalinity Alkalinity (from Arabic """"al-qalī"""") is the capacity of water to resist changes in pH that would make the water more acidic. (It should not be confused with basicity which is an absolute measurement on the pH scale.) Alkalinity is the strength of a buffer solution composed of weak acids and their conjugate bases. It is measured by titrating the solution with a monoprotic acid such as HCl until its pH changes abruptly, or it reaches a known endpoint where that happens. Alkalinity is expressed in units of meq/L (milliequivalents per liter), which corresponds to the amount of monoprotic acid"
"Acid–base titration An acid–base titration is a method of quantitative analysis for determining the concentration of an acid or base by exactly neutralizing it with a standard solution of base or acid having known concentration. A pH indicator is used to monitor the progress of the acid–base reaction. If the acid dissociation constant (p""K""a) of the acid or base dissociation constant (P""K""b) of base in the analyte solution is known, its solution concentration (molarity) can be determined. Alternately, the p""K""a can be determined if the analyte solution has a known solution concentration by constructing a titration curve. Alkalimetry and acidimetry"
"are a kind of volumetric analysis in which the fundamental reaction is a neutralization reaction. Alkalimetry is the specialized analytic use of acid-base titration to determine the concentration of a basic (synonymous to alkaline) substance. Acidimetry, sometimes spelled acidometry, is the same concept of specialized analytic acid-base titration, but for an acidic substance. A suitable pH indicator must be chosen in order to detect the end point of the titration. The color change or other effect should occur close to the equivalence point of the reaction so that the experimenter can accurately determine when that point is reached. The pH"
"+ ""m"" + ""m"" + ""m"" - ""m"""". Total alkalinity is measured by adding a strong acid until all the anions listed above are converted to uncharged species. The total alkalinity is not (much) affected by temperature, pressure, or pH, though the values of individual constituents are, mostly being conversions between HCO and CO. Drever further notes that in most natural waters, all anions except HCO and CO have low concentrations. Thus carbonate alkalinity, which is equal to ""m"" + 2""m"" is also approximately equal to the total alkalinity. Alkalinity or A measures the ability of a solution to neutralize"
"given in the unit mEq/L (milliequivalent per liter). Commercially, as in the swimming pool industry, alkalinity might also be given in parts per million of equivalent calcium carbonate (ppm CaCO). Alkalinity is sometimes incorrectly used interchangeably with basicity. For example, the addition of CO lowers the pH of a solution. This increase reduces the basicity; however, the alkalinity remains unchanged (see example below).For total alkalinity testing, N/10 HSO is used by hydrologists along with phenolphthalein indicator. In typical groundwater or seawater, the measured alkalinity is set equal to: Alkalinity can be measured by titrating a sample with a strong acid"
"to assess the liquidity of a business. The use of the term ""acid test"" for experiences with the psychedelic drug LSD was popularised by the Merry Pranksters, and derives from the drug's common name, ""acid"". Acid test (gold) An acid test is any qualitative chemical or metallurgical assay which uses acid; most commonly, and historically, the use of a strong acid to distinguish gold from base metals. Figuratively, acid test is any definitive test for some attribute, e.g. of a person's character, or of the performance of product. Testing for gold with acid focuses on the fact that gold is"
"many attempts to measure, record, and study oceanic alkalinity. Some of the larger data sets are listed below. The following packages calculate the state of the carbonate system in seawater (including pH): Alkalinity Alkalinity (from Arabic """"al-qalī"""") is the capacity of water to resist changes in pH that would make the water more acidic. (It should not be confused with basicity which is an absolute measurement on the pH scale.) Alkalinity is the strength of a buffer solution composed of weak acids and their conjugate bases. It is measured by titrating the solution with a monoprotic acid such as HCl"
"Salicylate testing Salicylate testing is a category of drug testing that is focused on detecting salicylates such as acetysalicylic acid for either biochemical or medical purposes. Salicylates can be identified by GC/MS, proton NMR, and IR. One of the first ""in vitro"" tests for aspirin was through the Trinder reaction. Aqueous ferric chloride was added to a urine sample, and the formation of the iron complex turned the solution purple. This test was not specific to acetylsalicylic acid but would occur in the presence of any phenol or enol. The downfall of this test occurs in the presence of hyperbilirubinemia"
"Nitrate test A nitrate test is a chemical test used to determine the presence of nitrate ion in solution. Testing for the presence of nitrate via wet chemistry is generally difficult compared with testing for other anions, as almost all nitrates are soluble in water. In contrast, many common ions give insoluble salts, e.g. halides precipitate with silver, and sulphate precipitate with barium. The nitrate anion is an oxidizer, and many tests for the nitrate anion are based on this property. Unfortunately, other oxidants present in the analyte may interfere and give erroneous results. A common nitrate test, known as"
"Alkali denaturation test The alkali denaturation test, also known as A or Apt test, is a medical test used to differentiate fetal or neonatal blood from maternal blood found in a newborn's stool or vomit, or from maternal vaginal blood. The test was developed by Leonard Apt (1922–2013), an American pediatric ophthalmologist. The test was originally used to identify the source of bloody stools in newborn infants. It has been modified to distinguish fetal from maternal hemoglobin in blood samples from any source. The Apt test is most commonly used in cases of vaginal bleeding late during pregnancy (antepartum haemorrhage)"
"ligand. Alkali denaturation test The alkali denaturation test, also known as A or Apt test, is a medical test used to differentiate fetal or neonatal blood from maternal blood found in a newborn's stool or vomit, or from maternal vaginal blood. The test was developed by Leonard Apt (1922–2013), an American pediatric ophthalmologist. The test was originally used to identify the source of bloody stools in newborn infants. It has been modified to distinguish fetal from maternal hemoglobin in blood samples from any source. The Apt test is most commonly used in cases of vaginal bleeding late during pregnancy (antepartum"
"Bicinchoninic acid assay The bicinchoninic acid assay (BCA assay), also known as the Smith assay, after its inventor, Paul K. Smith at the Pierce Chemical Company, is a biochemical assay for determining the total concentration of protein in a solution (0.5 μg/mL to 1.5 mg/mL), similar to Lowry protein assay, Bradford protein assay or biuret reagent. The total protein concentration is exhibited by a color change of the sample solution from green to purple in proportion to protein concentration, which can then be measured using colorimetric techniques. A stock BCA solution contains the following ingredients in a highly alkaline solution"
"Acidity function An acidity function is a measure of the acidity of a medium or solvent system, usually expressed in terms of its ability to donate protons to (or accept protons from) a solute (Brønsted acidity). The pH scale is by far the most commonly used acidity function, and is ideal for dilute aqueous solutions. Other acidity functions have been proposed for different environments, most notably the Hammett acidity function, ""H"", for superacid media and its modified version ""H"" for superbasic media. The term acidity function is also used for measurements made on basic systems, and the term basicity function"
"Acid test (gold) An acid test is any qualitative chemical or metallurgical assay which uses acid; most commonly, and historically, the use of a strong acid to distinguish gold from base metals. Figuratively, acid test is any definitive test for some attribute, e.g. of a person's character, or of the performance of product. Testing for gold with acid focuses on the fact that gold is a noble metal which is resistant to change by corrosion, oxidation, or acid. The acid test for gold is to rub the gold-colored item on black stone, which will leave an easily visible mark. The"
"acids to the equivalence point of carbonate or bicarbonate. The alkalinity is equal to the stoichiometric sum of the bases in solution. In the natural environment carbonate alkalinity tends to make up most of the total alkalinity due to the common occurrence and dissolution of carbonate rocks and presence of carbon dioxide in the atmosphere. Other common natural components that can contribute to alkalinity include borate, hydroxide, phosphate, silicate, dissolved ammonia, the conjugate bases of some organic acids, and sulfate. Solutions produced in a laboratory may contain a virtually limitless number of bases that contribute to alkalinity. Alkalinity is usually"
"nitrogen dioxide. Nitrate test A nitrate test is a chemical test used to determine the presence of nitrate ion in solution. Testing for the presence of nitrate via wet chemistry is generally difficult compared with testing for other anions, as almost all nitrates are soluble in water. In contrast, many common ions give insoluble salts, e.g. halides precipitate with silver, and sulphate precipitate with barium. The nitrate anion is an oxidizer, and many tests for the nitrate anion are based on this property. Unfortunately, other oxidants present in the analyte may interfere and give erroneous results. A common nitrate test,"
"test for uric acid and some other purines. The (solid) sample is first treated with conc. nitric acid, which is slowly evaporated away; subsequent addition of ammonia solution (NHOH) gives a purple color if uric acid was present, due to formation of murexide, or a yellow color that turns to red on heating if a xanthine is present. Murexide test The murexide test is an analytical technique to identify the presence of caffeine and other purine derivatives in a sample. These compounds do not respond to the common alkaloid detecting tests such as Dragendorff's reagent. In this test the alkaloids"
"dioxide. Many TOC analyzers suggest testing their instruments with two standards: one typically easy for the instrument to oxidize (KHP), and one more difficult to oxidize. For the latter, benzoquinone is suggested. Potassium hydrogen phthalate Potassium hydrogen phthalate, often called simply KHP, is an acidic salt compound. It forms white powder, colorless crystals, a colorless solution, and an ionic solid that is the monopotassium salt of phthalic acid. KHP is slightly acidic, and it is often used as a primary standard for acid-base titrations because it is solid and air-stable, making it easy to weigh accurately. It is not hygroscopic."
"Acid value In chemistry, acid value (or neutralization number or acid number or acidity) is the mass of potassium hydroxide (KOH) in milligrams that is required to neutralize one gram of chemical substance. The acid number is a measure of the number of carboxylic acid groups in a chemical compound, such as a fatty acid, or in a mixture of compounds. In a typical procedure, a known amount of sample dissolved in an organic solvent (often isopropanol) and titrated with a solution of potassium hydroxide (KOH) of known concentration using phenolphthalein as a color indicator. The acid number is used"
"Zeisel determination The Zeisel determination or Zeisel test is a chemical test for the presence of esters or ethers in a chemical substance. It is named after the Czech chemist Simon Zeisel (1854–1933). In a qualitative test a sample is first reacted with a mixture of acetic acid and hydrogen iodide in a test tube. The ensuing reaction results in the cleavage of the ether or the ester into an alkyl iodide and respectively an alcohol or an carboxylic acid. By heating this mixture, the gases are allowed to come into contact with a piece of paper higher up the"
"chloride (often abbreviated to CASS) each one chosen for the evaluation of decorative coatings, such as electroplated copper-nickel-chromium, electroplated copper-nickel or anodized aluminum. These acidified test solutions generally have a pH of 3.1 to 3.3 Some sources do not recommend using ASS or CASS test cabinets interchangeably for NSS tests, due to the risk of cross-contamination, it is claimed that a thorough cleaning of the cabinet after CASS test is very difficult. ASTM does not address this issue, but ISO 9227 does not recommend it and if it is to be done, advocates a thorough cleaning. Although the majority of"
"Heidelberg test The Heidelberg test is a medical diagnostic test used in the diagnosis of hypochlorhydria, i.e. insufficient hydrochloric acid in the stomach. When performing the Heidelberg test, the patient swallows a small electronic device about the size of a vitamin capsule. This device tracks acid levels in the stomach as the patient swallows small amounts of baking soda, which neutralises the hydrochloric acid in the stomach. If the acid level does not return to normal after the baking soda is swallowed, the patient has hypochlorhydria. The capsule is attached to a long thread to control the position of the"
"PH In chemistry, pH () is a logarithmic scale used to specify the acidity or basicity of an aqueous solution. It is approximately the negative of the base 10 logarithm of the molar concentration, measured in units of moles per liter, of hydrogen ions. More precisely it is the negative of the base 10 logarithm of the activity of the hydrogen ion. At 25 °C, solutions with a pH less than 7 are acidic and solutions with a pH greater than 7 are basic. The neutral value of the pH depends on the temperature, being lower than 7 if the"
"solutions depend upon the materials to be tested. The most common test for steel based materials is the Neutral Salt Spray test (often abbreviated to NSS) which reflects the fact that this type of test solution is prepared to a neutral pH of 6.5 to 7.2. Results are represented generally as testing hours in NSS without appearance of corrosion products (e.g. 720 h in NSS according to ISO 9227). Synthetic seawater solutions are also commonly specified by some companies and standards. Other test solutions have other chemicals added including acetic acid (often abbreviated to ASS) and acetic acid with copper"
"Seliwanoff's test Seliwanoff’s test is a chemical test which distinguishes between aldose and ketose sugars. Ketoses are distinguished from aldoses via their ketone/aldehyde functionality. If the sugar contains a ketone group, it is a ketose. If a sugar contains an aldehyde group, it is an aldose. This test relies on the principle that, when heated, ketoses are more rapidly dehydrated than aldoses. It is named after Theodor Seliwanoff, the chemist that devised the test. When added to a solution containing ketoses, a red color is formed rapidly indicating a positive test. When added to a solution containing aldoses, a slower"
"than three reagents. The calculation of hydrogen ion concentrations, using this formalism, is a key element in the determination of equilibrium constants by potentiometric titration. PH In chemistry, pH () is a logarithmic scale used to specify the acidity or basicity of an aqueous solution. It is approximately the negative of the base 10 logarithm of the molar concentration, measured in units of moles per liter, of hydrogen ions. More precisely it is the negative of the base 10 logarithm of the activity of the hydrogen ion. At 25 °C, solutions with a pH less than 7 are acidic and"
"work, he received the Nobel Prize in Chemistry in 1903. Thus Dittmar's alkalinity is the hydronium cations which exist to balance electrically the increase in calcium anions in deep ocean water, although now the meaning alkalinity has expanded. Alkalinity roughly refers to the amount of bases in a solution that can be converted to uncharged species by a strong acid. The cited author, James Drever, provides an equation expressed in terms of molar equivalents, which means the number of moles of each ion type multiplied by (the absolute value of) the charge of the ion. For example, 1 mole of"
"14104 is one of the standards detailing this well known procedure. Commercially available aqueous blends of 5–30% nitric acid and 15–40% phosphoric acid are commonly used for cleaning food and dairy equipment primarily to remove precipitated calcium and magnesium compounds (either deposited from the process stream or resulting from the use of hard water during production and cleaning). The phosphoric acid content helps to passivate ferrous alloys against corrosion by the dilute nitric acid. Nitric acid can be used as a spot test for alkaloids like LSD, giving a variety of colours depending on the alkaloid. Nitric acid is a"
"Ferric chloride test The ferric chloride test is used to determine the presence of phenols in a given sample or compound (for instance natural phenols in a plant extract). Enols, hydroxamic acids, oximes, and sulfinic acids give positive results as well. The bromine test is useful to confirm the result, although modern spectroscopic techniques (e.g. NMR and IR spectroscopy) are far superior in determining the identity of the unknown. The quantity of total phenols may be spectroscopically determined by the Folin-Ciocalteau assay. The sample is dissolved in water, or a mixture of water and ethanol, and a few drops of"
"Citrate test The citrate test detects the ability of an organism to use citrate as the sole source of carbon and energy. Bacteria are inoculated on a medium containing sodium citrate and a pH indicator such as bromothymol blue. The medium also contains inorganic ammonium salts, which are utilized as sole source of nitrogen. Use of citrate involves the enzyme citrase, which breaks down citrate to oxaloacetate and acetate. Oxaloacetate is further broken down to pyruvate and carbon dioxide (CO). Production of sodium bicarbonate (NaHCO) as well as ammonia (NH) from the use of sodium citrate and ammonium salts results"
"of salt water solution, prepared in accordance with the requirements of the test standard and acidified (to pH 3.1 to 3.3) by the addition of acetic acid. This spray is set to fall-out on to the specimens at a rate of 1.0 to 2.0ml/80 cm²/hour, in a chamber temperature of +35C. This climate is maintained under constant steady state conditions. The test duration is variable. ASTM G85 annex A2 – Acidified Salt Fog Test (cyclic). This test can be used to test the relative resistance to corrosion of aluminium alloys when exposed to a changing climate of acetic acid salt"
"product of iron hydroxide. There are multiple techniques to determine the p""K"" of a chemical, leading to some discrepancies between different sources. Well measured values are typically within 0.1 units of each other. Data presented here were taken at 25 °C in water. More values can be found in thermodynamics, above. Acid dissociation constant An acid dissociation constant, ""K"", (also known as acidity constant, or acid-ionization constant) is a quantitative measure of the strength of an acid in solution. It is the equilibrium constant for a chemical reaction known as dissociation in the context of acid–base reactions. In aqueous solution,"