How do you look at the reaction? Is it heat or heat?
There were several ways to determine whether the reaction was an exhalation or an absorption: 1. According to the energy relationship between the reagent and the product, if the total energy of the reagent is higher than the total energy of the product, the reaction is an exothermic reaction; if the total energy of the reagent is lower than the total energy of the product, the reaction is an xenothermic reaction. 2. According to the bond energy, it could be judged that the total bond energy of the reagent minus the total bond energy of the product. If the total bond energy of the reagent was greater than the total bond energy of the product, then the reaction was an heat absorbing reaction. If the total bond energy of the reagent was less than the total bond energy of the product, then the reaction was an heat absorbing reaction. 3. According to the basic types of chemical reactions, the reactions of acid and base, most of the displacement reactions, and most of the chemical combination reactions were all exothermic reactions. Most of the decomposition reactions were also the thermal reactions. The reactions of salt decomposition and dissolution were also the thermal reactions. However, this method of judgment could not be absolute. For example, the decomposition of kClO4 to produce kCl4 and oxygen was an geothermal reaction, and the transformation of lead to diamond under high pressure was an geothermal reaction (the opposite was true under normal pressure). 4. According to whether the reaction process required continuous external force, most of the exothermic reactions could be carried out spontaneously without continuous external force (such as light, electricity, etc.), but there were also exothermic reactions that required ignition or heating to occur (such as the reaction of hydrogen and oxygen to form water). There were also situations where the reaction could be carried out spontaneously without continuous external force, such as the reaction of lithium bis (bis). However, it was not possible to determine whether the reaction was an exhalation or an absorption simply based on whether an external force was needed. 5. According to the stability of the substance in the reaction, the reaction of forming an unstable substance from a stable substance was an alcoholic reaction, and vice versa. In addition, it was important to note that the dilute of concentrated sulfuric acid, the dissolution of the solid in water, and the heat absorption of the solid in water were not chemical reactions, nor were they in the scope of the heat absorption reaction or the heat release reaction. Read more exciting novels for free
reaction heat exchange
The reaction heat exchange was also known as the heat exchange reactor, and its structure was mostly similar to the shell-and-tube heat exchange. The catalyst could be placed in the tube or between the tubes, but it was rare to place it between the tubes. In a heat-exchange fixed-bed reactor, the gas flows from the top of the reactor down into the catalyst bed and flows out at the bottom. In actual production, this top-down flow method is mostly used. For the heat-exchange tube reactor, the reasonable choice of heat carrier was the key to control the reaction temperature and maintain the stable operating conditions of the reactor. The temperature difference between the heat carrier and the reaction temperature of the bed should be small, but it must be able to take away the heat released by the reaction. This required a large heat transfer coefficient under the condition of a certain heat transfer area. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Does the decomposition reaction release heat and the combination reaction absorb heat?
Most of the chemical reactions were exothermic, because the chemical reaction was a bond formation process, and the bond formation process was exothermic. However, there were also some chemical reactions that were xenothermic, such as C + CO2 = 2CO2. Most of the decomposition reactions were heat-absorbing reactions because the process of the decomposition reaction was a bond breaking process, and the bond breaking process was an heat-absorbing process. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Is the weak acid reaction heat-absorbing or heat-releasing?
It was too general to say that the weak acid reaction was either heat absorbing or heat releasing. For example, the weak acid's ionisation process was heat absorbing. This was because the weak acid needed to overcome the effect of chemical bonds to absorb energy when it was ionised. However, if a weak acid is involved in the neutralizing reaction, since the weak acid is not completely ionised, it absorbs heat during the neutralizing reaction at the same time. Therefore, the heat released by the neutralizing reaction of the weak acid and the strong base (or strong acid) is less than the neutralizing heat of the strong acid and strong base neutralizing reaction.(The neutralizing reaction of a diluted solution of a strong acid and base: H+(aq)+Oh-(aq) H2O(l); AH = -57.3kJ/mole), but the whole reaction was still an exothermic reaction, but the heat released was less than that of a strong acid and base neutralizing reaction. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Heat Reaction of Iodide and Amylum
Based on context alone At room temperature, there was no reaction between potassium iodate (Ki) and starch. However, if the mixture of potassium iodate and starch was heated under acidic conditions, a reaction would occur. Under acidic conditions, the ion equation of the potassium iodate is: 4I +4H + O 2 = 2I 2 + 2H 2 O. Iodine (I <2>) could turn the starch blue because it was embedded in the gaps of the starch's spiral structure, forming a blue clathrate. In general, the essence of the heating reaction between potassium iodate and starch was that the potassium iodate was first oxided to produce iodate, and then the iodate reacted with the starch. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Heat Reaction of Dibasic Acid
Oxalic acid was a dibasic acid. The two groups of the acid could be decarboxylated at a lower temperature to form formated acid and CO2. At a higher temperature, formated acid would undergo a dehydration reaction to form CO2 and water. The reaction equation was as follows: At lower temperatures: <<<p>></p>H - COOH + CO_2↑\); At higher temperatures: <br><br><br>> br><br>> br></br>>CO_2↑+ CO↑+ H_2O\)。 After the dibasic acid was heated, due to the different positions of the two carboxy groups, different chemical reactions such as water loss, loss of esh, or loss of esh at the same time would occur. At 300 ° C, the substituted dibasic acid could also undergo the above reactions. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Solar heat, physical reaction
The physical reaction of the sun's heat is nuclear fusion. In the high-temperature and high-pressure environment inside the sun, under extremely high temperature and pressure, the electrons outside the nucleus were freed from the constraints of the nucleus, and the nuclei attracted each other and collided with each other. To be specific, it was a reaction where four hydrogen atoms fused into one helium atom. This process would release a huge amount of energy, which was the principle of the sun's heat. According to the mass-energy equation E = MC2, the sun could emit a steady stream of light and heat by losing a little mass in this process. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
supersonic heat reaction equipment
The working principle of the ultrasonic heating reaction equipment was that the energy-gathering ultrasonic horn was directly immersed in the reaction liquid of the reaction kettle, and a large amount of energy was directly transmitted to the reaction medium, effectively transforming the electrical energy into mechanical energy or ultrasonic energy. The ultrasonic energy could be controlled by changing the amplitude of the ultrasonic wave transmitted to the probe through the ultrasonic generator. For example, the Voshin - 1200 UIG high-pressure and high-temperature ultrasonic reactor was commonly used in laboratory extraction and chemical reaction research. It solved the problem of sealing the horn and the reactor. It could also be equipped with various chemical reactor accessories at high temperatures to achieve the reaction system atmosphere isolation and vapor condensation. There were also related ultrasonic heating machines available on the market. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
The reaction of no2 and n2o4 absorbs heat
The reaction between NO2 and N2O4 was N2O4 (g) 2NO2 (g), and the reaction had a Ah = +24.4 kJ/mole (or Ah = +57 kJ/mole, which was slightly different from different data but was positive), indicating that the reaction was an heat absorption reaction, that is, the absorption of heat caused the reaction to proceed in the direction of the formation of NO2. In the reaction process, when the temperature of the system increased, according to Le Chatelier's principle, the equilibrium would move in the direction of heat absorption, which was to produce more NO2. Conversely, when the temperature decreased, the equilibrium would move in the direction of N2O4. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
The reaction of dicarbonic acid under heat
The reaction of the dicarbonic acid after being heated was more complicated, and it would have different reactions affected by the relative position of the two carboxy groups. Some will lose water, some will lose starch, and some will lose both water and starch. The details were as follows: 1. Oxalic acid and malonic acid and their alkyls: easy to lose the ester. 2. Butanediic acid and glutanic acid and their alkyls: Butanediic acid loses its water when heated to about 300 ° C to form butanediic acid; glutanediic acid loses its water when heated to about 300 ° C to form glutanediic acid, which is not easy to undergo decylating reaction. 3. Hexanic acid and pimelic acid and their alkyls: When heated to about 300 ° C, they lose both the acid and the water. Hexanic acid can be heated to form Cyclopentane. 4. When the dicarbonic acid above the pimelic acid is heated, it loses water between the molecules to form a high-molecular acid ether. In addition, in the heating reaction of the dicarbonic acid, if the water loss reaction occurs, it may be necessary to add a water loss agent, such as Ag2O, P2O2, CHCOCl2,(CHCO2) 2O, POCl2, etc.; If the decarbonic acid reaction occurs, it may be necessary to add a base, such as Ba(Ox) 2, Ca2 (Ox) 2, etc. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
The most suitable reaction temperature for a reverse-heat reaction
In the case of a revertible thermal reaction, the chemical reaction constant was a positive function of temperature. The higher the temperature, the faster the reaction speed. However, increasing the temperature in a revertible thermal reaction had a contradictory effect. On the one hand, as the positive reaction proceeded, the system would release heat and the temperature would increase, and the reaction would speed up. On the other hand, the reverse reaction would also speed up as the temperature increased, which would weaken the positive reaction. Therefore, there was an optimal temperature at which the reaction rate was the greatest. This temperature was called the optimal temperature. In the case of the industrial synthesis of hydrogen, which was an example of a reversibility, from the perspective of increasing the reaction rate and increasing the content of hydrogen, the actual industrial production used a temperature of 400 - 500 ° C, and the iron catalyst was the most active at around 500 ° C. In addition, in order to make the overall reaction speed and conversion rate of the irreversible exothermic chemical reaction process fast, a temperature segment control scheme can be used to make it change according to the optimal conversion rate temperature curve trajectory. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>