Methyl orange alkalinity

Figure 29.5. Values of pH of water at elevated temperatures (Powell, Bacon, and Lill [5]). (a) For water at 25 ppm alkalinity (methyl orange end point). (f>) For water of 100ppm alkalinity (methyl orange end point).

Alkalinity Methyl orange or methyl red Spectrophotometry 10-200 mgr Online titration... 

M alkalinity Methyl orange alkalinity. (See total alkalinity.)... 

Example. Dissolve 0 3 g. of benzoic acid in a minimum of hot water (about 70 ml.) and add 5% aqueous sodium hydro.xide until the solution is just alkaline to methyl-orange, then add i drop of dilute hydrochloric acid. Pour this solution of the sodium salt into a solution of 0 5 g, of benzylthiouronium chloride in 5 ml. of water, and cool the stirred mixture in ice-water. Filter off the benzylthiouronium salt which has separated, and recrystallise from ethanol con taining 10% of water cream-coloured cr> stals, m.p. i66 . (M.ps., pp. 543 545.)... 

Formation of methyl-orange cf. p. 214). Dissolve about 0 3 g. of sul-phanilic acid in 2 ml. of 10% aqueous NajCOj solution. Cool m ice-water and add 2 to 3 drops of 20% NaNOj solution. Now add about I ml. of cold dil. HCl, shake and leave for 2-3 minutes. Meanwhile dissolve i drop of dimethylaniline in a few drops of dil. HCl, cool thoroughly in ice-water and then add to the cold diazo solution. Shake well and make alkaline with aqueous NaOH solution note the formation of a deep orange-yellow coloration or precipitate. On the addition of HCl, a bright red coloration is produced. 

Most water analysis results are rather easily interpreted. However, two simple and useful tests need explanation. These are the P and M alkalinity. The water is titrated with N/30 HCl to the phenolphthalein end point at pH 8.3. This is called the P alkalinity. Similar titration to the methyl orange end point at pH 4.3 is called the M alkalinity. They are reported as ppm CaCO,. 

The sulphanilic acid is dissolved in the sodium carbonate (i mol.) solution and the sodium nitrite (i mol.) solution added. The mixture is cooled in ice, and the solution of hydrochloi ic acid (i mol.) gradually added. The solution of dimethylaniline (i mol.) is now poured in, and the liquid made alkaline with caustic soda. The separation of methyl orange at once begins, and is assisted by the addition of a little common salt (20 grams). The precipitate is filtered at the pump, and crystallised from hot water. Yield, nearly theoretical. 

Alkalinity and Lime Content. Alkalinity is the ability of a solution or mixture to react with an acid. The phenolphthalein alkalinity refers to the amount of acid required to reduce the pH to 8.3, the phenolphthalein endpoint. The phenolphthalein alkalinity of the mud and mud filtrate is called the and Pp respectively. The P. test includes the effect of only dissolved bases and salts while the P test includes the effect of both dissolved and suspended bases and salts. The methyl orange alkalinity refers to the amount of acid required to reduce the pH to 4.3, the methyl orange endpoint. The methyl orange alkalinity of the mud and mud filtrate is called the and Mp respectively. The API diagnostic tests include the determination of P, Pp and Mp All values are reported in cubic centimeters of 0.02 N (normality = 0.02) sulfuric acid per cubic centimeter of sample. 

Excessive viscosity and yield point. YP cannot be lowered with thinner. Increase in 10 min gel strength. Methyl Orange alkalinity M, > 5... 

Commercial samples of water are frequently alkaline due to the presence of hydrogencarbonates, carbonates, or hydroxides. The alkalinity is determined by titrating a 100.0 mL sample with 0.02M hydrochloric acid using screened methyl orange as indicator (or to a pH of 3.8). To obtain the total cation content in terms of CaC03, the total methyl orange alkalinity is added to the EMA. 

With 0.1M solutions, the ideal pH range for an indicator is limited to 45-9.5. Methyl orange will exist chiefly in the alkaline form when 99.8 mL of alkali have been added, and the titration error will be 0.2 per cent, which is negligibly small for most practical purposes it is therefore advisable to add sodium hydroxide solution until the indicator is present completely in the alkaline form. The titration error is also negligibly small with phenolphthalein. 

The requirements of the US Armed Forces are contained in Mil Spec JAN-B-660, Barium Oxalate (For Use In Ammunition) , (5 Aug. 1948) Color — white moisture — 0.3% max material insol in 10% HC1 soln - 0.5% max material sol in water - 0.3% max water sol alkalinity — 0.1% max water sol acidity — the water extract shall not be acid to methyl orange barium oxalate — 92% min calcium salts —... 

FWTH = FW total hardness, in mg/1 (ppm) CaC03 FWMA — FW methyl orange/total alkalinity, in mg/1 CaC03 RBWMA — Required BW methyl orange alkalinity, in mg/1 CaC03 COC — Cycles of FW concentration present or desired in the BW... 

Alkalinity content may be tested and reported in various ways, but for BW, the most important tests are methyl orange/total alkalinity (reported as M or T alkalinity, expressed as mg/1, mg/kg, or ppm CaC03), and caustic /hydroxide alkalinity (reported as OH alkalinity, expressed as mg/1, mg/kg, or ppm CaC03). 

In the boiler, the BW phenolphthalein alkalinity (P alkalinity) usually is more than half of the total or methyl orange alkalinity (T or M alkalinity) ... 

Primarily the sum of carbonate, bicarbonate and hydrate ions in water, but phosphate, silicate etc. may also contribute partially to alkalinity. Normally expressed as ppm (mg/1) CaC03. Phenolphthalein alkalinity (P Aik.) is that portion of alkalinity titrated with acid to pH 8.2 end-point, while total alkalinity (T Aik. or M Aik.) is that titrated with methyl orange indicator to pH 4.2 endpoint. 

A method suitable for quantification of the functional class of bis(ethanol)amine antistatics, which lack UV chromophores, consists of reaction with methyl orange [53]. Atmer 163 (alkyl-diethanol amine) has been determined as a yellow complex at 415 nm after interaction with a bromophenol/cresole mixture [64]. Hilton [65] coupled extracted phenolic antioxidants with diazotised p-nitroaniline in strongly acidic medium and carried out identification on the basis of the visible absorption spectrum in alkaline solution. The antioxidant Nonox Cl in... 

The aq. soln. of trisodium phosphate reacts alkaline to methyl orange, phenol-phthaleln, and litmus and neutral to Porrier s blue. The aq. soln. of trirubidium and tricsesium phosphates also react alkaline. J. Shields, J. M. van Bemmelen, and A. Kossel found that in aq. soln., trisodium phosphate is almost completely hydrolyzed by water into disodium hydrogen phosphate and sodium hydroxide. E. Salm calculated that the degree of hydrolysis is about 23 per cent, of the sodium or 70 per cent, of theP04 E. Blanc that 34 1 per cent, of a O O A-soln. VOL. II. 3 i... 

The ash, especially if fairly large in amount, is tested for mineral adulterations, such as sodium sulphate, alum, sodium chloride, clay, etc. Sometimes the alkalinity of the soluble ash is required (e.g.,to confirm the presence of molasses), this being determined by dissolving the ash in boiling water, filtering and titrating with N/10-sulphuric acid in presence of methyl orange. The alkalinity is expressed as parts of potassium carbonate per 100 of dry matter.1... 

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