Is the reaction of ammonium salt with alkali endothermic?

Not (1) The enthalpy change of the hydroxide of the second main group metal element in the solid-phase reaction with ammonium chloride decreases sequentially in the order of be mg ca sr ba, and changes from endothermic reaction to exothermic reaction. For example, the hydroxide reaction of ammonium chloride with beryllium, magnesium, calcium, and strontium is an endothermic reaction, while the reaction with barium hydroxide is an exothermic reaction. The reaction of ammonium chloride with Ba(OH)2 is exothermic reaction, while the reaction of ammonium chloride with Ba(OH)2·8H2O is endothermic reaction.

This is a special case. (2) The enthalpy change of the hydroxide of the first main group metal element in the solid-state reaction with ammonium chloride decreases in the order of Li Na k Rb, and changes from endothermic reaction to exothermic reaction. For example, the reaction of ammonium chloride with lithium hydroxide is endothermic reaction, and the reaction with hydroxide of sodium, potassium and rubidium is exothermic reaction.

3 Enthalpy change of reaction between other ammonium salts and Ba(OH)2·8H2O (solid-state reaction). In summary, the reaction of ammonium chloride with Ba(OH)2· 8H2O is endothermic reaction, while the reaction with Ba(OH)2 is exothermic reaction. The reaction between ammonium salt and alkali has both endothermic and exothermic reactions; Therefore, in the teaching of chemistry in middle school, it cannot be simply concluded that the reaction between ammonium salt and alkali is an endothermic reaction.

The change in energy in a chemical reaction is usually mainly manifested as a change in heat – endothermic and exothermic, and some reactions are endothermic reactions. In view of the experiments in the second chapter and the first section of the high school chemistry compulsory course 2 of the People's Education Press: Experiments on the reaction of NH4Cl and Ba(OH)2·8H2O in chemical reactions and heat**, it was found through experiments and data query and processing

The reaction between ammonium chloride and Ba(OH)2·8H2O is endothermic reaction, while the reaction between ammonium chloride and Ba(OH)2 is exothermic reaction, and it cannot be concluded that the reaction between ammonium salt and alkali is endothermic reaction.

Salt and alkali react to form another salt and another base.

The base reacts with the salt to form a new base (a relatively weak base) and a new salt. There are two requirements for the reaction between alkali and salt, one of which requires that the alkali and salt involved in the reaction be soluble in water, and the other requires that there is precipitation, gas or water in the product. For example, sodium hydroxide reacts with copper sulfate:

2naoh+cuso4===cu(oh)2+na2so4；The chemical equation for the reaction of sodium hydroxide with ferric chloride: 3NaOH+FeCl3===Fe(OH)3+3NaCl.

Salts refer to a class of compounds in which metal ions or ammonium ions (NH4) are combined with acid ions or non-metal ions. Such as sodium chloride, calcium nitrate, ferrous sulfate and ammonium acetate, calcium sulfate, copper chloride, sodium acetate, etc. Generally speaking, salt is the product of metathesis reaction, salt and salt reaction to form new salt and new salt, salt and alkali reaction to form new salt and new alkali, salt and acid reaction to form new salt and new acid, such as sulfuric acid and sodium hydroxide to form sodium sulfate and water, sodium chloride and silver nitrate reaction to form silver chloride and sodium nitrate, etc.

The principle that alkali and salt can generate gas is that the cation of hydroxide and salt generates gas through certain conditions, and the common one is that alkali and ammonium salt generate ammonia under heating conditions.

The reaction principle of alkali and salt to produce water is the reaction of hydroxide ions ionized by alkali and hydrogen ions ionized by salt, that is, the reaction between alkali and acid salt, the common reaction between hydroxide and bisulfate, hydroxide and bicarbonate and so on.

Alkali and salt reaction: NaOH+NH?cl=nacl+nh?

h?o。Both alkali and salt are soluble, and it is common for strong bases and weak salts to react to form weak bases and strong salts.

The reaction that occurs between acid, alkali and salt solutions is formed by the exchange of components between two compounds.

That is, the compounds participating in the metathesis reaction are ionized in the aqueous solution and dissociated into free-moving ions, and the ions are recombined into new compounds. On the one hand, the metathesis reaction is a requirement for reactants: salt, acid and alkali are generally OK, and salt salt and salt alkali need to be dissolved.

On the other hand, there are requirements for the products: there are precipitation precipitation or gas release in the products, or weak electrolytes such as water are generated. Both of these aspects must be taken into account in order to correctly write the chemical equations for metathesis reactions.

The chemical reaction equation for the reaction of ammonium salt and base is: 2nHCl + Ca(OH) = 2nH +CaCl +2HO.

The ionic equation is: NH HCO = NH CO Ho (all conditions are heated).

Ammonium salts are ionic compounds, all of which are white crystals (NH4MNO4 is purple-black), soluble in water, and absorb heat when dissolved in water. When cold, the two are recombined into ammonium chloride, which is similar to the phenomenon of "sublimation", but different from the sublimation of I2. NH4HCO3 is completely vaporized when heated, and a phenomenon similar to "sublimation" also occurs.

The products of thermal decomposition of ammonium salt should be analyzed according to the specific situation, which is generally related to many factors such as temperature and oxidation of acid groups in ammonium salt.

There are two processes for the dissolution of a scrambler substance in water, one is the process of dispersion of solid (or liquid solute) molecules or ions into the solvent, which absorbs heat; The other process is the chemical process in which solute molecules or ions react with water molecules to form hydrates, which release heat.

Whether the solution is exothermic or endothermic when formed depends on how much heat is released and absorbed in these two processes. If the heat absorbed is greater than the heat released, the temperature of the solution decreases, and vice versa, the temperature of the solution increases.

Ammonium salts are generally dissolved and are endothermic. For example, ammonium nitrate absorbs more heat than it emits when it is dissolved, and the same is true for ammonium chloride. But any book only says most cases, so it cannot be generalized that all ammonium salts are dissolved by heat and rotten.

ba(oh) +2nh4cl ==bacl2 + 2nh3 + 10h2o

Among them, barium hydroxide octahydrate and chlorine ammonium are both solid.

Summary. Nitrate and base reaction are endothermic. This is because the nitrate and base reaction can produce heat, and this heat can be absorbed, thus making the reaction exothermic.

The reason for this reaction is that there is a chemical reaction between nitrate and alkali which can produce heat which makes the reaction exothermic. The solution to this reaction exothermic is to use a coolant to lower the reaction temperature and thus reduce the heat of the reaction exothermy. In addition, a chemical reactor can be used to control the temperature of the reaction, thereby reducing the heat of the reaction exotherm.

In addition, chemical reactors can be used to control the temperature of the reaction, thereby reducing the heat of the reaction exothermia. In short, nitrate and alkali reaction endothermy, can be used to reduce the heat of reaction exothermic by using coolant, chemical reactor and other methods, so as to achieve the purpose of controlling the reaction temperature.

Nitrate and base reaction are endothermic. This is because the reaction between nitrate and alkali can produce heat, and this heat can be absorbed, so that the reaction is exothermic. The reason for this reaction is that there is a chemical reaction between the nitrate and the base, and this counter-defeat should produce heat, which makes the reaction exothermic.

The solution to this reaction exothermic is to use a coolant to lower the reaction temperature and thus reduce the heat of the reaction exothermy. In addition, a chemical reactor can be used to control the temperature of the reaction, thereby reducing the heat of the reaction exotherm. In addition, the reaction temperature can be controlled using a chemical retort to reduce the heat of the reaction exothermy.

In short, nitrate and alkali reaction endothermy, can be used to reduce the heat of reaction exothermic by using coolant, chemical reactor and other methods, so as to achieve the purpose of controlling the reaction temperature.

Excuse me, but please go into more detail?

The nitrate and base reaction is an exothermic reaction. This is because the reaction of nitrate and alkali will produce water and salt, the dissolution process of water will release heat, and the dissolution process of salt will absorb heat, but the heat absorbed by the dissolution process of salt is much less than the heat emitted by the dissolution process of water, so the nitrate and alkali reaction is an exothermic reaction in general. The exothermic reaction of nitrate and base reaction can be used to refrigerate, it can be used to make ice cubes, and it can also be used to refrigerate food and medicines.

In addition, nitrate and alkali reactions can also be used to make water heaters, which are used to heat water to meet people's daily needs. The exothermic reaction of nitrate and alkali reaction can also be used to generate electricity, and the principle that it can be used to generate electricity is: the heat generated by the reaction of nitrate and alkali can be used to heat water, and the steam of water can be used to propel a steam turbine to produce electricity.

In conclusion, nitrate and alkali reaction is an exothermic reaction, which can be used to cool down, heat water, and generate electricity, which provides great convenience for people's daily life.