Sulfuric acid specific heat

In sulfuric acid the heat of sorption and desoiption of hydrogen in the region of the phase transition amoimts to 10 0 kcal/mole, which is in agreement with the published data [17]. Specific adsorption of cadmium cations on the palladium surface increases the heat of the jS O phase transition to 25 kcal/mole. The difference found in the heats of the direct and reverse transition is thermodynamically impossible, if the processes occur at the same centers, uniform in chemical composition. 

Traditionally, sodium dichromate dihydrate is mixed with 66° Bh (specific gravity = 1.84) sulfuric acid in a heavy-walled cast-iron or steel reactor. The mixture is heated externally, and the reactor is provided with a sweep agitator. Water is driven off and the hydrous bisulfate melts at about 160°C. As the temperature is slowly increased, the molten bisulfate provides an excellent heat-transfer medium for melting the chromic acid at 197°C without appreciable decomposition. As soon as the chromic acid melts, the agitator is stopped and the mixture separates into a heavy layer of molten chromic acid and a light layer of molten bisulfate. The chromic acid is tapped and flaked on water cooled roUs to produce the customary commercial form. The bisulfate contains dissolved CrO and soluble and insoluble chromic sulfates. Environmental considerations dictate purification and return of the bisulfate to the treating operation. 

Specific Heat of Nitric Acid, Sulfuric Acid, and Water Mixtures.. . Nitration of Hexamine at 20°C and —35.5°C. 

Fig 20 Specific heat of nitric acid, sulfuric acid, and water mixtures McKinley and Brown (Ref 28a)... 

Figure 5.1 is a graph of the specific heat capacity cp (heat capacity per gram) of aqueous sulfuric acid solutions at T — 298.15 K against A, the ratio of moles of water to moles of sulfuric acid. The values plotted were obtained from a very... 

Some agrochemicals bind strongly to the soil component as bound residues, which cannot be extracted without vigorous extraction procedures. In this case, an acidic (e.g., hydrochloric acid, sulfuric acid) or alkaline solution (e.g., sodium hydroxide, potassium hydroxide) can be used as an extraction solvent, and also heating may be effective in improving the extraction of the residues. Analytical procedures after the extraction are the same as above, but a filtration procedure may be troublesome in some of these situations. However, these procedures are rare exceptions or are needed for specific chemicals that are stable under such harsh extraction conditions. 

In the following year, however, he concluded that tire mineral contained neither bismuth sulfide nor antimony, that the gold was an essential constituent of it, and that it contained an unknown metal. In an investigation lasting three years and consisting of more than fifty tests, he determined the specific gravity of the mineral and noted the radish odor of the white smoke which passed off when the new metal was heated, the red color which the metal imparts to sulfuric acid, and the black precipitate which this solution gives when diluted with water (3). 

Add 120 g. of powdered potassium bromide to 200 ml. of water. Place the container in cold water, and slowly add 90 ml. of cone, sulfuric acid (1.7 mols). The temperature should not go appreciably above 75°C. otherwise a small amount of free bromine may be formed. However, the formation of a small amount of bromine is not particularly serious, since it will come over with the distillate boiling between 100 to 115°C. Cool the solution to room temperature, and remove the potassium acid sulfate by filtering through a hardened filter paper in a Buchner funnel. Place the filtrate in a 500-ml. distilling flask connected to a water condenser fitted with an adapter, and heat over a wire gauze. If the presence of 0.01 to 0.015 per cent of sulfate ion is not objectionable, reserve the distillate that starts to come over 1° below the temperature of the constant-boiling mixture. The distillation should be stopped when the temperature drops. The specific gravity of the solu-... 

The effectiveness of dilution is highly chemical-specific and must be well conceived and tested. For instance, the improper addition of another material to a spill could cause the rapid evolution of heat, which could accelerate the evaporation rate and make the situation worse. Even with the proper diluent selection, the method and rate of addition are both important for controlling vapor evaporation rates. If water is to be used as a diluent for a material with a high heat of dilution, such as sulfuric acid or oleum, it must be added rapidly and in a large enough quantity to not only effect the dilution, but also serve as a heat sink for the heat of dilution produced. In this way, high evaporation rates for the pool being diluted will be minimized. 

Determine the heat of mixing AH of sulfuric acid in water and the partial specific entl of H2SO., and for a solution containing 70-wt-% H2S04 at 140(°F). 

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