Filter weighing

Filter Weighing Procedure-. The step-by-step procedure for weighing filters depends on the make and model of the balance. Consult the manufacturer s instruction book for directions. In addition, follow these guidelines ... 

The solid product of hydrolysis is loaded out of the nutsch filter, weighed and sent into reactor 14 through a hatch the reactor also receives solid sodium hydroxide. After that, backflow condenser 13 is filled with water, the agitator is switched on and the reactive mixture is gradually filled with ethyl alcohol (or hydrosite) from batch box 72 at such speed that the temperature in the reactor does not exceed 80 °C. After the whole mixture has been introduced, the jacket is filled with vapour and agitated for 1-2 hours at 75-80 °C. The mixture is cooled to 20 °C and poured into... 

Note The following steps describe a specific method of filtering, weighing and mounting the sample. The instructor may provide alternate instructions for preparing the barium sulfate source appropriate for the available counting facilities. 

Optimisation and standardisation of sampling procedures is complicated by the number of experimental parameters which must be considered such as filter type and temperatures, dimensions, filter weighing conditions (temperatures and relative... 

Remove as much of the cake as possible from the filter, weigh it, dry it and reweigh it. From these measurements, calculate the ratio of the mass of wet/dry cake. 

After the end of the experiment the reactor was withdrawn fi-om the fiimace, cooled in air to room temperature, and taken apart. The tube was taken out of the reactor and the salt melt was washed with water. The precipitate of the refractory compound was collected and washed on a filter. Then the precipitate was dried, removed fi om the filter, weighed, and underwent the X-ray phase and chemical analyses. 

Hi-vol filter and other filters—measures all of the nonvolatile mass in None 25 2 pg/m Filter-weighing ... 

The sulphate ion is detected by addition of barium chloride in the presence of hydrochloric acid a white precipitate of barium sulphate is obtained. The same test can be used to estimate sulphate, the barium sulphate being filtered off, dried and weighed. 

Addition of calcium nitrate solution to a fluoride gives a white precipitate of calcium fluoride, CaFj. If the latter is precipitated slowly, it can be filtered off and weighed to estimate the fluoride. Fluoride can also be determined by the addition of sodium chloride and lead nitrate which precipitate lead chlorofluoride, PbClF. This is filtered off and weighed. 

Addition of silver nitrate to a solution of a chloride in dilute nitric acid gives a white precipitate of silver chloride, AgCl, soluble in ammonia solution. This test may be used for gravimetric or volumetric estimation of chloride the silver chloride can be filtered off, dried and weighed, or the chloride titrated with standard silver nitrate using potassium chromate(VI) or fluorescein as indicator. 

Filter the mixed product at the pump, and wash it well with ethanol to remove excess of dimedone, and then with water and again with ethanol. The dried white residual methylene-dimedone , m.p. 186-188°, weighs o 55-o-65 g. It may be recrystallised from ethanol containing about 10% of water, and then has m.p. 189°. 

The iV-methylanthranilic acid rapidly separates. Cool the mixture in ice-water, filter off the acid at the pump, wash thoroughly with water and drain. The crude acid if now dried weighs 1 5 g. and has m.p. 166-170°. 

Add 4 g. of malonic acid to 4 ml. of pyridine, and then add 3 1 ml. of crotonaldehyde. Boil the mixture gently under reflux over an asbestos-covered gauze, using a small Bunsen flame, for 40 minutes and then cool it in ice-water. Meanwhile add 2 ml. of concentrated sulphuric acid carefully with shaking to 4 ml. of water, cool the diluted acid, and add it with shaking to the chilled reaction-mixture. Sorbic acid readily crystallises from the solution. Filter the sorbic acid at the pump, wash it with a small quantity of cold water and then recrystallise it from water (ca, 25 ml.). The colourless crystals, m.p. 132-133°, weigh ro-i-2 g. 

Proceed as in (A), using 50 ml. of ethanol, with boiling for 20 minutes. The quinoxaline (III) crystallises readily during the boiling. Cool the mixture, filter off the quinoxaline, and wash it with ethanol. The dry product, of m.p. 220 225", weighs 1 3 g. Recrystallise the quinoxaline from chloroform or acetic acid pale yellow crystals, m.p. 226°. Yield, 0 9-ro g. 

Principle. A known weight of the substance is heated with fuming nitric acid and silver nitrate in a sealed tube. The organic material is thus oxidised to carbon dioxide and water, whilst the halogen is converted quantitatively into the corresponding silver halide. The latter js subsequently washed out of the tube, filtered and weighed. 

To prepare the funnel G, fit it to the filter-flask and wash it by passing distilled water, ethanol and acetone through the glass plate H. Remove G from the bung J, wipe it with a clean cloth, and dry it in an oven for 15 minutes at 140°. Then carefully wipe it again with the cloth, and place it in the balance case on the carrier D (Fig. 90) for 15 minutes to attain an equilibrium with the air. Then transfer it to the balance pan and weigh. 

Now fit the weighed funnel G again to the filter-flask, and attach the Pregl filter-tube K as shown (Fig. 21). Apply 2i gentle suction from the water-pump, and dip the open limb of the tube K just below the surface of the liquid in the Carius tube. Draw off the supernatant liquid a little at a time until rather less than 1 ml. remains. Now gently shake the mixture in the Carius tube, and try to adjust the suction so... 

Prepare a solution of casein as follows. Weigh out 15 g. of casein into a dry 500 ml. conical flask and add about 150 ml. of water. Dissolve 1 5 g. of anhydrous sodium carbonate and i 5 g, of borax in about 20 ml. of hot water and add this solution to the casein. Warm until a solution is obtained, filter if necessary, and make up to a total volume of about 250 ml. with water. Add a few drops of toluene (to prevent putrefaction) and shake the solution. 

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