Hydrochloric acid dilution calculation

Procedure Prepare a Sample Solution of approximately 0.5 absorbance unit at 560 nm by transferring an appropriate amount of sample into a 100-mL volumetric flask with the aid of 0.025 N hydrochloric acid. Dilute to volume with 0.025 N hydrochloric acid, and centrifuge or filter if the solution is cloudy. Add 140 mg of Special Reagent to a 20-mL aliquot of the Sample Solution, mix thoroughly for several minutes, centrifuge or filter, and collect the clear supernatant liquid. Determine the absorbance of the Sample Solution and of the supernatant liquid in a 1-cm cell at 560 nm, with a suitable spectrophotometer previously standardized using 0.025 N hydrochloric acid as a reference. Calculate the percent of color bound by DEAE cellulose by the formula... 

Sucrose Pipet 100 mL of Sample Solution into a 200-mL volumetric flask, and add slowly 10 mL of 2.7 N hydrochloric acid, diluted 1 1, while gently swirling the solution place in a constant-temperature bath maintained at 60° agitate continuously for 3 min and allow to sit in the bath for an additional 7 min. Remove the flask from the bath, and cool to 20° as rapidly as possible dilute to volume with water, and mix well. Continue as directed in the Procedure (above) under Invert Sugar. Calculate the percent invert sugar present after hydrolysis (PH) using the equation... 

From the results in very dilute hydrochloric acid we calculate A == 44.1 0-1 min- mole 1 and from the result in sodium chloride solution we estimate... 

Elute the nicotinamide with 500 ml of 0-005N hydrochloric acid, dilute to 1 litre and measure the extinction of a 1-cm layer at about 261 m/n Calculate the weight of nicotinamide in a tablet of average weight using an E(1 per cent, 1 cm) of 411 at 261 m/z. 

Concentrate the combined filtrate and washings (W) to about half the original volume, and pour it into sUghtly more than the calculated amount of dilute hydrochloric acid (use a mixture of 30 ml. of concentrated hydrochloric acid and 30 ml. of ice-water) then add about 300 ml. of water. Collect the active aec.-octyl hydrogen phthalate (crude lA) as above (5). The weight of the air-dried ester is about half that of the dl-ester originally used (7). 

The alkaline solution of thymol is made up to 100 or 200 c.c. as the case may require, using a 5 per cent, soda solution. To 10 c.c. of this solution in a graduated 500 c.c. flask is added a normal iodine solution in shgbt excess, whereupon the thymol is precipitated as a dark reddish-brown iodine compound. In order to ascertain whether a sufficient quantity of iodine has been added, a few drops are transferred into a test tube and a few drops of dilute hydrochloric acid are added. When enou iodine is present, the brown colour of the solution indicates the presence of io ne, otherwise the liquid appears milky by the separation of thymol. If an excess of iodine is present, the solution is slightly acidified with dilute hydrochloric acid and diluted to 500 c.c. From this 100 c.c. are filtered,off, and the excess of iodine determined by titration with normal solution of sodium thiosulphate. For calculation, the number of cubic centimetres required is deducted from the number of cubic centimetres of normal iodine solution added and the resultant figure multiplied by 5, which gives the number of cubia centimetres of iodine required by the thymol. 

The hydrochloride of this base, obtained by evaporation to dryness of a solution of the base in dilute hydrochloric acid and subsequent treatment of the residue with ethyl alcohol and acetone, had a chlorine content of 18.84%, (calculated, 18.90%). 

After 6 hours the calculated amount of hydrogen has been taken up. The residue obtained after filtering and evaporating is taken up in benzene and extracted twice with diluted sodium carbonate solution. The alkali extract is then made acid to Congo red with 6N hydrochloric acid and the precipitate is taken up in ethyl acetate. The solution obtained is washed twice with salt solution, dried with sodium sulfate and evaporated. The residue is recrystallized from ether/petroleum ether. 1-(p-hydroxyphenyl)-2-phenyl-4-n-butyl-3,5-dioxo-pyrazolidine melts at 124° to 125°C. 

Procedure B. The experimental details for the preparation of the initial solution are similar to those given under Procedure A. Titrate 25 or 50 mL of the cold solution with standard 0.1M hydrochloric acid and methyl orange, methyl orange-indigo carmine, or bromophenol blue as indicator. Titrate another 25 or 50 mL of the cold solution, diluted with an equal volume of water, slowly with the standard acid using phenolphthalein or, better, the thymol-blue cresol red mixed indicator in the latter case, the colour at the end point is rose. Calculate the result as described in the Discussion above. 

Note on the gravimetric standardisation of hydrochloric acid. The gravimetric standardisation of hydrochloric acid by precipitation as silver chloride is a convenient and accurate method, which has the additional advantage of being independent of the purity of any primary standard (compare Section 10.38). Measure out from a burette 30-40mL of the, say, 0.1M hydrochloric acid which is to be standardised. Dilute to 150 mL, precipitate (but omit the addition of nitric acid), and weigh the silver chloride. From the weight of the precipitate, calculate the chloride concentration of the solution, and thence the concentration of the hydrochloric acid. 

Reagents. Standard calcium solution. Prepare a standard solution containing 40.0 mg L 1 calcium by dissolving the calculated quantity of calcium carbonate in the minimum amount of hydrochloric acid and diluting to 1 L in a graduated flask. 

Color Diluting Solution. This is prepared by mixing 5 volumes of absolute ethyl alcohol, 1 volume of concentrated hydrochloric acid, and 4 volumes of 2 to 1 sulfuric acid. It is made up just before use. (In the equation for calculation of results, this solution is referred to as Solution B.)... 

In a small round-bottomed flask which has been frequently used and well steamed, an accurately weighed amount of benzyl chloride (about 1 g.) is boiled for one hour under reflux with one and a half times the calculated amount of approximately normal alcoholic sodium hydroxide solution the solution is then diluted with two volumes of water, and the excess of alkali is titrated with 0-5 N-hydrochloric acid after addition of phenolphthalein. 

Wollaston s method, of which the preceding is a modification, is the most perfect, and that best calculated to yield a pure metal,. Vauquelin struck upon the same, but in its details that of the former is the most complete. For tire preparation of the pure metal, the platiniferous grains arc treated with aqua regia and chloride of ammonium, as in the preceding case ouly, to prevent the solution of the iridium it is necessary to dilute the acids, so that it will remain in the residue. It is well to reduce the strength of the- hydrochloric acid with on equal quantity of water, and also that the aqua-fortis and muriatic acid bo quite pure. - Wollaston has indicated that a quantity of ydrochlorio acid, equivalent to one hundred and fifty of dry acid, and as much nitric acid as will contein forty parts, Is sufficient for the solution of a hundred parts of the platiniferous matter hut as it is best to have an excess of the ore, one hundred and twenty parts of the latter should be employed. The action of the compound acid should... 

Triamino-4-methylphenyl-1 -sulphonic acid or its hydrochloride is dissolved in the calculated quantity (1 or 2 mols. respectively) of very dilute sodium hydroxide, then one molecular proportion of acid sodium selenite added, followed by the slow addition of 0 12V hydrochloric acid until a precipitate is obtained. After a time this precipitate is collected and dissolved in hot sodium hydroxide, the sodium salt separating on cooling as fine reddish-yellow needles. 

A mixture of 50 c.c. of the beer with 15 c.c. of hydrochloric acid (D 1-125) is diluted to 200 c.c. and heated for 2 hours on a boiling water-bath in a flask fitted with a long tube to serve as a condenser. When cold, the liquid is neutralised exactly with caustic soda and made up to 250 c.c. or, with a beer rich in extract, to 300 c.c. In 25 c.c. of this solution the glucose formed by inversion is determined by the method given on pp. 108 and no and calculated by means of Table XII (p. no). Since, however, part of the glucose found is derived from the inversion of the maltose, the amount of glucose found per 100 c.c. of the beer must be diminished by the amount of maltose present, multiplied by 1-053. The remainder, multiplied by 0-9, represents the quantity of dextrin in 100 c.c. of the beer. 

The precipitate is dissolved in a little hot dilute hydrochloric acid and the aluminium hydroxide reprecipitated with ammonium chloride and ammonia. The precipitate is allowed to settle, washed by decantation and then on the filter with slightly ammoniacal hot water. The weight ol oxide obtained after igniting in a platinum crucible in a blowpipe flame is multiplied by two and the result diminished by the quantity normally present in wine (0 -o 1-0 -04 gram A1,0-, per litre). The remainder is calculated as alum. 

Hyponitrites are produced by the action of sodium amalgam, that is, a solution of sodium in mercury containing about 4 per cent, of the former, on a solution of potassium or sodium nitrite. After the mixture has stood for some days, it is rendered slightly acid with acetic acid, and silver nitrate is added. A yellow precipitate of silver hyponitrite is produced other hyponitrites may be prepared from it by the addition of the calculated quantity of the respective chloride. The acid can also be liberated by the addition to a very dilute aqueous solution of the equivalent amount of hydrochloric acid. On warming the solution of the acid, nitrous oxide is evolved but nitrous oxide does not unite with water to form the acid. 

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