877-24-7 potassium acid phthalate

For standardizing a base solution, primary standard grade potassium biphthalate is a popular choice. Also called potassium hydrogen phthalate, potassium acid phthalate, or simply KHP, it is the salt representing partially neutralized phthalic acid and is a monoprotic weak acid. The true formula is KHC8H404. Figure 5.8 shows the chemical structure of phthalic acid and KHP. The reaction with a base is as follows ... 

Mueller and Bandaranayake [39] were able to show that more than 95% of the following compounds were oxidised in the first run, when present in the water sample at the 5 mg C per litre level oxalic acid, potassium phthalate, humic acid, glucose, sucrose, ascorbic acid, glycine, and phenol. Only sulfur compounds gave incomplete recoveries [58,88]. 

Synonyms potassium biphthalate potassium acid phthalate acid potassium phtalate phthalic acid potassium acid salt KHP... 

Potassium hydrogen phthalate Potassium hydrogen phthalate Potassium iodate Anhydrous sodium carbonate Zinc metal Standardisation of sodium hydroxide solution Standardisation of acetous perchloric acid Standardisation of sodium thiosulphate solution through generation of iodine Standardisation of hydrochloric acid Standardisation of EDTA solution... 

The oxidation of ascorbic acid at a platinum electrode in potassium acid phthalate buffer (pH 6) has been reported at +1.09 V vs. SCE [16]. Under these... 

A. Sodium hydroxide solution 0.3125 N (12.5 g per liter sodium hydroxide reagent grade. Standardize against potassium acid phthalate). 

Amidosulfuric acid Potassium Hydrogen Phthalate Potassium Dichromate Potassium Chloride Arsenic Oxide... 

Phthalate 5.9 5.1 g Potassium acid phthalate 0.86 g Sodium hydroxide (W20)... 

Cool, covering the condenser with foil to prevent contamination by moisture, and rinse the condenser with glacial acetic acid. Add 5 drops of crystal violet TS, and titrate with 0.1 A potassium acid phthalate in glacial acetic acid to a blue-green endpoint. Perform a blank determination (see General Provisions), and make any necessary correction. Each milliliter of 0.1 A perchloric acid is equivalent to 20.53 mg of C9H19NO4. 

Potassium Acid Phthalate, 0.1 N [20.42 g KIICfin4(COO)2 per 1000 mL] Dissolve 20.42 g of primary standard potassium biphthalate [ KHC6H4(COO)2], previously dried at 105° for 2 h, in glacial acetic acid in a 1000-mL volumetric flask, wanning on a steam bath if necessary to effect solution and protecting the solution from contamination by moisture. Cool to room temperature, dilute to volume with glacial acetic acid, and mix. 

After washing with. 5 M HBr twice, the In is back-extracted into 6 g HC1. The HC1 iB evaporated to 1 ml and the pH adjusted to 2.-3 by addition of NaOH. Potassium acid phthalate buffer (pH 2,k) is then added to bring the soln. volume to 20 ml. 

If 5.033 g of potassium hydrogen phthalate, an acid salt having one ionizable hydrogen atom and a molar mass of... 

Disodium hydrogen phthalate-sodium dihydrogen orthophosphate Dipotassium hydrogen phthalate-potassium dihydrogen orthophosphate Potassium dihydrogen orthophosphate-sodium hydroxide Barbitone sodium-hydrochloric acid Tris (hydroxylmethyl) aminomethane-hydrochloric acid... 

A hydrogen gas electrode in 0.05 molar potassium acid phthalate, when combined with a calomel electrode tontaining saturated potassium chloride, gave a cell with an b.m.p. of 0.4765 volt at 38°. Calculate the pH of the solution which gave an e.m.f. of 0.7243 volt in a similar cell. 

Formaldehyde-water solution. Mix 50 ml of 38% formaldehyde with 50 ml of distd w in a 400-ml beaker, add 4 drops of 1% phenolphthalein or thymolphthalein indicator (0.8g per 100ml ethanol) and neutralize with carbonate-free 0.5N NaOH soln dropwise to a pink color (pH 8.6) on glass-calomel electrode system Standard sodium hydroxide, 0.5N. Dissolve 20g of carbonate-free NaOH in 500ml CO2-free water, add enough Ba chloride to more than 2 liters distd w to precipitate carbonate present, let the Ba carbonate settle, and filter into a 1 liter volumetric flask. Standardize the NaOH soln by adding it. from a buret into a soln of 2 g of potassium acid phthalate (weighed accurat ely on an analytical balance), and four drops of phenolphthalein indicator in 75—100ml COa-free water contained in a 150-ml beaker until the first appearance of a pink end point... 

Bleach (chloride of lime) Bromine Butyl acetate Butyl phthalate Butyric acid Calcium carbide Calcium cyanamide Calcium hypochlorite Calcium nitrate Calcium potassium ferrocyan-ide (double salt)... 

As substrate materials five different single crystals have been chosen potassium chloride (KC1), sodium chloride (NaCl), potassium acid phthalate (KAP) [27], muscovite mica [28], and phlogopite mica. All are cleaved in air and are transferred immediately into a high vacuum system (base pressure 2 x 10 8 mbar). Either right away or after annealing a clear low energy electron diffraction (MCP-LEED, Omicron) pattern is observed for each of them. Organic molecules are deposited from an effusion cell. The nominal deposited film thickness is estimated by a water-cooled quartz microbalance located next to the substrate. 

Sodium hydroxide is usually standardized by titrating a weighed quantity of primary standard potassium acid phthalate (KHP), which is a moderately weak acid Ka = 4 X 10 ), approximately like acetic acid a phenolphthalein end point is used. The sodium hydroxide solution should be stored in a plastic bottle to prevent absorption of CO2 from the air. If the bottle must be open (e.g., a siphon bottle), the opening is protected with an Ascarite (asbestos impregnated with NaOH) tube. 

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