Bromothymol blue indicator

Acidity. Mix 100ml of sample with 100ml of freshly-boiled distd w (free of C02), add 2 drops of bromothymol blue indicator (0,04% LaMotte or Taylor solns) and titrate with 0.01N Na hydroxide soln to a blue endpoint. Calculate the acidity as acetic acid as follows ... 

This one is just plain fun.9 Place 900 mL of water and a magnetic stirring bar in each of two 1-L graduated cylinders. Add 10 mL of 1 M NH3 to each. Then put 2 mL of phenolphthalein indicator solution in one and 2 mL of bromothymol blue indicator solution in the other. Both indicators will have the color of their basic species. 

Chemical equilibrium and analysis of a mixture. A remote optical sensor for C02 in the ocean was designed to operate without the need for calibration.21 The sensor compartment is separated from seawater by a silicone membrane through which C02, but not dissolved ions, can diffuse. Inside the sensor, C02 equilibrates with HCO3 and CO3-. For each measurement, the sensor is flushed with fresh solution containing 50.0 pM bromothymol blue indicator (NaHIn) and 42.0 pM NaOH. All indicator is in the form HIn-or In2 near neutral pH, so we can write two mass balances (1) [HIn ] + [In2-] = Fln = 50.0 pM and (2) [Na"] = FNa = 50.0 pM + 42.0 pM = 92.0 pM. HIn- has an absorbance maximum at 434 nm and In2 has a maximum at 620 nm. The sensor measures the absorbance ratio RA = A620/A434 reproducibly without need for calibration. From this ratio, we can find C()2( [Pg.420]

Mannitol (10%). Dissolve 10 g mannitol, C6H, 4Oe, in water, and neutralize the solution with 0 01m sodium hydroxide against bromothymol blue indicator, until the colour of the solution just turns to green. 

Add 2 drops of bromothymol blue indicator solution to wells D2, C2, and B2. This indicator turns from blue to yellow as the solutions become more acidic. Record your observations. 

Hydrobromic acid and potassium hydroxide are referred to as the parent acid and the parent base of potassium bromide. Test several aqueous salt solutions with bromothymol blue indicator to determine whether the solutions are acidic (yellow), basic (blue), or neutral (green). 

According to the color of each solution that has bromothymol blue indicator added, is each of the solutions acidic, basic, or neutral ... 

B Add a few drops of bromothymol blue indicator to the HCI solution in the flask. The solution turns yellow. 

FIGURE 15.9 (Left) A beaker of water to which a few drops of bromothymol blue indicator have been added. (Right) As dry ice is added to the water, the CO2 reacts to form carbonic acid, which turns the solution acidic and changes the color from blue to yellow. 

Reagent The carrier stream (1.0 x 10" M NaOH, carbonate free) is prepared by mixing 5 mL of 0.1 M sodium hydroxide (it is convenient to use, for example, Titrisol standard solution Merck, Germany) with 50 mL of 96% ethanol and 2 mL bromothymol blue indicator stock solution (see Section 6.3), making the final volume up to 500 mL with distilled water. 

Other colour tests which do not interfere in the subsequent quantitative determination, can be of only limited application. An example is with organic phosphorus compoimds, where the substance can be ignited and determined through its phosphorus content [166, 258]. Glycolipoid fractions have been localised with ammoniacal bromothymol blue indicator and then, after extraction, evaluated with anthrone/sul-phuric acid [324]. 17-Hydroxycorticosteroids have been sprayed with blue tetrazolium and then determined with phenylhydrazine/sulphuric acid [11] the steroids partly reacted with the identification reagent which led to difficulties. 

SIA manifold for carbon speciation in bathing waters. BTB bromothymol blue indicator Detector spectrophotometer (Xmax = 611 nm) Detector (MRC) multireflection cell coupled to light-emitting diode (Xmax = 660 nm) HC holding coil RC reaction coil SV selection valve. 

Bromothymol blue indicator. Dissolve 100 mg of indicator in 1.6 mL of 0.1 mol/L sodium hydroxide solution and dilute to 100 mL. 

Bromothymol blue indicator. Dissolve 0 1 g of dry indicator in 16 ml of 0 01 N sodium hydroxide by grinding the indicator with the alkali in a mortar. Transfer to a 100-tnl graduated flask, dilute to volume with water and mix. 

Cool the tube slightly and dissolve the residue in about 20 ml of de-ionized water, warming if necessary. Finally cool the solution in cold water, preferably in an ice bath, and add one drop of bromothymol blue indicator (Note b). 

Figure 21.7 shows how the pH changes when 0.100 mol dm sodium hydroxide (a strong base) is titrated with 0.100 mol dm hydrochloric acid (a strong acid) in the presence of bromothymol blue indicator. 

With the exception of Be, the four alkaline-earth salts in solution can be determined by direct titration with standard EDTA solution at pH 12 using bromothymol blue indicator. 

Water and sufficient aq. NaOH added to n-propyl(dimethylaminomethyl)malo-nic acid to render the soln. neutral to bromothymol blue indicator, and refluxed overnight in a Ng-atmosphere a-n-propylacrylic acid. Y 67%. F. e. s. M. F. Hawthorne, Am. Soc. 82, 1886 (1960) method s. G. Mannich and E. Ganz, B. 55, 3486 (1922). 

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