Bunsen’s method

IODINE- —Estimation op Iodine—Penny and Bunsen s Methods. 401 ... 

Bunsen s method for the extraction of the two rare potassium metals from a given mixture of alkaline salts is founded u[>oii the ciiTereiit snInhUity of the several alkaline chloroplatiuatea Accord ii .g 10 him 100 jfarts of vvalcr dissolve—... 

Ignition and Weighing of the Barium Sulphate. — In order to prepare the barium sulphate for weighing, it is not necessary to dry it before incineration if Bunsen s method is followed, it may be incinerated while Still moist. With the aid of a small spatula or knife the moist filter is removed from the funnel and folded in the form of a quadrant. Should any barium sulphate adhere to... 

Emil and his cousin transferred to Strasbourg in the fall of 1872. Studying under Rose, Fischer became acquainted with Bunsen s methods for the analysis of water. This experience proved useful when the young man did analsitical work for the town of Colmar. 

According to Bunsen s method, the urine is heated with a solution of barium oblotide in dihite ammonia to a temperature of 230, and the barium carbonate whidr separates out is weighed... 

The arrai ients for conduotmg a gas analysis according to Bunsen s method are shown in Eig. 213, which is a sketch of his gas-analysis room. 

This is Bunsen s method. When the solution is too strongly acidified, the small quantity of chlorates contained by the hypochlorite solution oxidizes iodide ions according to the reaction... 

Sulfite and hydrogen sulfite ions reduce iodine into iodides (see iodometry). They also reduce permanganate ions. They are simultaneously converted into sulfate ions (Bunsen s method) or into dithionite ions 8205 depending on the experimental conditions. The reaction must be carried out in a very acidic medium in order for the + II oxidation state of manganese to be reached and also to avoid the precipitation of manganese dioxide. Reduction reactions of permanganate are... 

Determination oflhe percentage oJ A vailahle Chlorine in a given sample of bleaching powder by Bunsen s method... 

Caesium compounds impart a reddish-violet coloration to the Bunsen flame, similar to that given by rubidium. The chloride forms an insoluble double chloride with stannic chloride of the formula CsgSnCle,1 and also a double salt with antimony chloride.2 Mackenzie and Marshall s method 3 described for rubidium (p. 199) is also applicable to the detection of caesium.4... 

Ewins s Method o-i-o-2 gm. of the substance is mixed in a 300 ml. Kjeldahl flask with 10 gm. potassium sulphate, o>2-o-3 gm. starch and 20 ml. concentrated sulphuric acid. This mixture is then heated by means of a Bunsen burner, first moderately for 10-15 minutes, then more vigorously for about 4 hours, until decomposition is complete. The liquid is cooled, transferred to a 350 ml. flask and made alkaline to litmus paper with sodium hydroxide. It is then cooled to 30° to 40° and sulphuric acid added drop by drop until the solution is faintly acid. A saturated solution of sodium bicarbonate is then added until the solution is again alkaline, 5-10 ml. being added in excess. The arsenious acid formed is then titrated with iodine solution using starch as indicator. 

In Bunsen s laboratory I had certainly learned analysis and become comfortable with gasometric methods, but had profited little from pure [i.e., theoretical] chemistry. Bunsen had lost all interest in organic chemistry.. . This explains why modern organic chemistry, which had its origins in France and England and was imported into Germany by Kekule (just as years earlier the chemistry of Gay-Lussac had been imported by Liebig), remained without protection or support in this country.. . . ... 

During his student years Auer also worked in Heidelberg in Bunsen s laboratory. It was there that he acquainted himself with the method of spectral analysis, and also with the old observation studied more systematically by Bunsen that the light emitted by the flame of the Bunsen burner increases by the effect of various elements and oxides. This phenomenon was studied much by Bunsen s co-workers, and it is said that Bunsen once pronounced that the ftiture of gas lighting will be ensured by a solid glowing in the gas burner s flame. This, at least, is what can be read in a... 

Bunsen s investigation seemed to show that terbium does not exist But the argument is dubious. Spectroscopy was in its infancy and the method was very empirical. 

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