reverse 1999 reaction

For a chemical reaction, one could judge the spontaneous nature of the reaction by the Gibbs free energy (? G=? H-T? S). When AG>0, the reaction proceeded spontaneously in reverse. 1. ** Analysis from the perspective of the change in the change in the temperature (? H) and the change in the temperature (? S)** - When a reaction that absorbs heat (Delta H>0) and reduces the entropies (Delta S<0), it must be a non-spontaneous reaction (forward), which is a reverse spontaneous reaction, because according to Delta G= Delta H-T Delta S, in this case, Delta G must be greater than 0. - For the reaction of decreasing entropies (? S<0) with an exothermic reaction (? H<0), increasing the temperature will make the reaction reverse spontaneously, because it is necessary to ensure that? G>0 (from? G=? H-T? S, when? H<0,? S<0, increasing T will increase? G and make it greater than 0). - For a reaction with an increase in entropies (? S>0) that is an encircling heat (? H>0), lowering the temperature will make the reaction reverse spontaneously, because it is necessary to ensure that? G>0 (from? G=? H-T? S, when? H>0,? S>0, a decrease in T will increase? G and make it greater than 0). 2. ** Analysis from the perspective of equilibrium constant (for a irreversible reaction)** - If the equilibrium constant of a reaction is K, when the reaction quotient J>K, the reaction will proceed spontaneously in the opposite direction. The equilibrium constant K is related to the standard mole Gibbs free energy change of the reaction, which can be calculated by the formula, where R is the gas constant and T is the temperature. The expression of the reaction quotient J is similar to the equilibrium constant K, except that the concentration or partial pressure is the actual value of the reaction at a certain time. When J>K, the reaction proceeded spontaneously in the opposite direction according to the equation: <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

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>

The reason why the positive reaction rate was greater than the reverse reaction rate was as follows: 1. ** Concentration Effect ** - When the concentration of the reagent increased, according to the collision theory, the effective collision frequency between the molecules of the reagent increased, and the positive reaction rate instantly increased. At this time, the concentration of the product had not changed, and the reverse reaction rate did not change. Therefore, the positive reaction rate was greater than the reverse reaction rate, and the reaction went forward. For example, in the reaction A + B, if the concentration of A or B increases, the positive reaction rate will increase before the reverse reaction rate. - When the concentration of the product was reduced, the reverse reaction rate would decrease. However, the positive reaction rate would not change when the concentration of the reagent remained unchanged. This would also cause the positive reaction rate to be greater than the reverse reaction rate, causing the reaction to move forward. 2. ** Effect of temperature (targeted at the heat reaction)** - For example, when the temperature was raised, the positive and reverse reaction rates increased. However, since the positive reaction was a thermal reaction, according to Le Chatelier's principle, the increase in temperature was not conducive to the progress of the thermal reaction, so the increase in the reverse reaction rate was greater than the increase in the positive reaction rate. Then, for a reaction that was a positive reaction, when the temperature was raised, the increase in the positive reaction rate was greater than the increase in the reverse reaction rate. The positive reaction rate was greater than the reverse reaction rate, and the reaction was positive. 3. ** Pressure effect (for reactions where the gas volume changes before and after the reaction)** - For example, for the reaction, the total volume of the gas before the reaction (1 + 3 = 4) is greater than the total volume of the gas after the reaction (2). When the pressure increases, according to the ideal gas state equation,[pV = nRT]([p] is the pressure,[V] is the volume,[n] is the amount of matter,[R] is the constant,[T] is the temperature), the gas concentration increases, and the positive and reverse reaction rates increase. However, because the reaction moved in the direction of decreasing the volume of the gas, the increase in the positive reaction rate was greater than the increase in the reverse reaction rate. The positive reaction rate was greater than the reverse reaction rate, and the reaction proceeded in the positive direction. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

The preparation of 1 -Bromobutan was slow and required a long reaction time at a high temperature. The highest reaction temperature that could be achieved in the glass reaction device was the temperature at which the reaction was carried out. Therefore, the reaction device was used. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

The reaction equation is: 2NaHSO2 + 2CH CH2Ox = Na SO2 +H SO2 + 2CH CH2Ox. The phenomenon of this reaction was not mentioned in the information provided, so it was impossible to give an accurate answer. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

The reaction between the acid and the acid would result in the formation of a sulfuric acid deposit. The reaction equation was Na Chi SiOx +2HNOOx == H Chi SiOx +2NaNOOx, and the reaction phenomenon was the formation of a white deposit. In this reaction, the sulfuric acid did not show any oxidisation, but only showed its acidic nature. This was because the silicon in the silica was already in the highest state, and the acidic nature of the sulfuric acid was stronger than that of the sulfuric acid, which was in line with the principle of making a weak acid from a strong acid. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

There is no chemical reaction between NaCl2 and magnesiumcarbonate2. In chemistry, the conditions for metathesis reactions to occur were the formation of precipitations, gases, or water. After mixing the two, the conditions for the metathesis reaction were not met, so there was no reaction, no reaction equation, and no reaction phenomenon. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

Aluminiothermic reaction was a kind of oxide-reduction reaction between aluminum and metal or non-metal compounds at high temperatures. Aluminiothermic reaction was an exhaling reaction, and its heat release was very large, usually enough to heat the product above the melting point, and the reaction could generally occur locally and be self-sustaining. This characteristic also reflected the energy-saving characteristics of the reaction. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

Rearrangement reaction refers to the migration of certain atoms or groups in the molecules of organic compounds under certain reaction conditions, resulting in the reorganization of the molecular structure. For example, the Beckmann Rearrangement Reaction was a reaction in which ketoximes were rearranged into N-substituted diamides under the action of an acidic catalyst; the Cope Rearrangement Reaction was a (3,3)-sigma-shift rearranging reaction of 1,5 -diene; the Hofmann-Martius Rearrangement Reaction was a reaction in which N-alkylated aromatic compounds were rearranged to the corresponding o-/p-alkylated aromatic compounds under the action of acid catalyst; the Curtius Rearrangement Reaction was a type of nuclopathic rearrangements. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

Additional reaction: - The addition reaction of ethene and Bromine: <<CH2 = CH2 + Br2> - The addition reaction of ethene and hydrogen bromidate was as follows: <CH2 = CH2> - Under certain conditions, addition reactions could also occur between ethene, hydrogen, and water. Since the chemical properties of ethyne (carbon-carbon triple bond) were similar to that of alkene (carbon-carbon double bond), similar addition reactions could also occur. - The aromatic ring can undergo an addition reaction with hydrogen (in the presence of a catalyst such as Ni). - Aldol groups can undergo a reduction reaction (addition reaction), such as: <anno data-annotation-id ="00000000 - 4c00 - 4c00 - 8c00 - 9c00 - 9c000b000000"> CH3CH20H </anno>. Substitution reaction: - The substitution reaction between methane and Cl2: CH4 + Cl2. - The substitution reaction of the aromatic ring: For example, the substitution reaction with the aromatic group using FeBr3 as a catalyst; the nitration reaction with the aromatic group using concentrated sulfuric acid under heating conditions (the hydrogen on the aromatic ring is replaced by the nitrogen group). - The substitution reaction of the halated carbon was as follows: <<CH3CH2Br2>+<NaBr2>>. - The substitution reaction of alcohol: <CH3CH20H>+<br>> longrightarrow <CH3CH2br>+<H2O>> - The ester's cleavage reaction (which can be seen as a substitution reaction):<CH3COOCH2CH3 + H2O> <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>