In high school chemistry, there were many ways to calculate the reaction between metal compounds and acid.
I. Analysis from the Essence of Reaction
1. * * Redox reaction essence **
- When a metal reacted with an acid, one had to consider the reduction of the metal and the oxidisation of the ions in the acid. For example, the reaction between sulfuric acid and metal, the nitrogen in the sulfuric acid has strong oxidisation in the presence of hydrogen. For example, the reaction between copper and dilute sulfuric acid was 3Cu+8H^++2NO3 ^-= 3Cu^{2 +}+4H2O +2NO3 ^-.
- When analyzing the reaction between a metal mixture and sulfuric acid, it was necessary to determine the order of the reaction (if there were multiple metals or multiple reactions), and determine the relationship between the amount of substances in the reaction of each substance according to the ion equation.
2. * * Ion reaction angle **
- If the metal ions in the metal mixture could have a specific reaction with the ions in the acid, it should also be analyzed from the nature of the ion reaction. For example, the essence of the reaction between Fe2 + and dilute sulfuric acid is 3Fe2 ++4H2O + NO3-= 3Fe2 ++2H2O + NO3.
II. Analysis of the role of nitric-acid in the reaction
1. * * The difference between acidic and oxidisable **
- Part of the sulfuric acid that participated in the reaction was acidic and formed nitrates. The other part was used as an oxidiser and was generally converted to nitrogen dioxide (NO) or NO2).
- During the calculation, the problem could be solved according to the conservation of nitrogen. For example, if a certain mass of
Different metals may react with acid to produce different colors: - The reaction between the dilute sulfuric acid and the dilute sulfuric acid produced a large number of bubbles. The chemical equation was: Mn +2HQ = Mn Cl2 + Mn Cl2, Mn + Mn Cl2 = Mn Cl2 + Mn Cl2 + Mn - The reaction between the two metals was intense and produced a large number of bubbles. The chemical equation was as follows: Mn +2HQ = Mn Cl2 + Mn Cl2, Mn + Mn Cl2 = Mn Cl2 + Mn Cl2 + Mn Cl2 = Mn Cl2 + Mn Cl2 = Mn Cl2 + Mn Cl2 + Mn Cl2 = Mn Cl2 + Mn Cl2 = Mn Cl2 + Mn Cl2 + Mn Cl2 = Mn Cl - When iron reacted with diluted sulfuric acid or sulfuric acid, a small amount of bubbles appeared on the surface of the nail. At the same time, the solution turned light green because of the formation of iron sulfuric acid or iron chloride.The reaction equation was: FeCl2 <2>+ H <2>, FeCl2 <2>= FeCl2 <2>+ H <2>, FeCl2 <2>= FeCl2 <2>= FeCl2 <2>+ H <2>. - Copper does not react with dilute sulfuric acid or dilute sulfuric acid. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
In the image problem of the reaction of metals with excessive acid, the following situations were mainly involved: ##1. The horizontal coordinate is reaction time. 1. ** Reaction Rate Relationship ** - When different metals react with excess acid, the reaction rate depends on the mobility of the metal. In the middle school chemistry exam, the metal activity was in the order of Mn> Mn. This meant that under the same conditions (such as the same concentration of acid, the same temperature, the size of the metal particles, etc.), the reaction rate from fast to slow was also: Mn> Mn. The image showed the degree of inclination of the diagonal line. The greater the inclination, the faster the reaction speed. 2. ** The final mass of hydrogen produced ** - When the same amount of different metals react with an excess of acid, the mass of hydrogen produced is related to the relative atomic mass of the metal (when the metal has the same valency). According to the chemical equation, the mass relationship of hydrogen produced by the reaction of a metal of the same mass with a sufficient amount of acid was as follows: The higher the platform, the greater the mass of hydrogen produced. ##2. The horizontal coordinate is the mass of the acid. 1. ** Reaction process analysis ** - In the process of increasing the mass of acid, the metal will react completely because there is a small amount of metal (acid excess). The quality of the corresponding acid after the reaction of different metals was different, and the quality of the hydrogen produced was also different. 2. ** Phased analysis of the quality of hydrogen produced ** - At different stages, depending on the activity and relative atomic mass of the metal, there would be different situations where the metal was in excess or completely reacted, which would affect the amount of hydrogen produced. For example, in a certain interval, there may be excessive or complete reaction of the iron, the aluminum, and the aluminum. At this time, the quality of the generated hydrogen would have a specific situation. As the acid quality increased, when entering the next interval, there may be insufficient amount of the iron, or the iron may be excessive or complete reaction. The aluminum and the aluminum may be excessive, and the quality of the hydrogen would change accordingly. ##3. Key Points 1. ** Judging excessive and small amount ** - First of all, he had to judge the excessive and small amount of metal and acid through the description in the question. For example, he could see the words "small amount","sufficient amount","excessive amount", etc. The final amount of hydrogen produced in the reaction was determined by the small amount of the reagent. 2. ** Explain the meaning of the horizontal and vertical coordinates ** - When analyzing the image, it was necessary to distinguish the specific meaning of the horizontal and vertical coordinates in the image. Generally, the vertical coordinate was the amount of hydrogen produced, and the horizontal coordinate might be the reaction time, the mass of acid consumed, or the mass of metal consumed. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
1. ** Reaction law of nitrates and metals ** - ** Passivation phenomenon **: Metal such as iron, aluminum, and aluminum are easily dissolved in dilute sulfuric acid, but they are not dissolved in cold concentrated sulfuric acid. This is due to the occurrence of a passive phenomenon. - ** Reaction with non-active metals ** - When the metal activity order table showed that the metal reacted with the metal after hydrogen, it could be seen that the metal was first oxided by the acid, and then the metal reacted with the acid to form nitrates. The main reduction product of concentrated sulfuric acid was NO2, and the main reduction product of diluted sulfuric acid was NO. For example, the reaction of silver with concentrated sulfuric acid: <2Ag +2HNO3 (concentrated)= Ag2O +2NO2 + H2O>,<Ag2O +2HNO3 = 2AgNO3 + H2O>, the total reaction is <2Ag +2HNO3 (concentrated)= AgNO3 + NO2 + H2O>; The reaction of silver with diluted sulfuric acid: <3Ag +4HNO3 (diluted)= 3AgNO3 +NO +2H2O>. - ** Reaction with active metals **: When sulfuric acid acts with the metal before hydrogen in the metal activity order table, in addition to the corresponding nitrates, the sulfuric acid may be further reduced to substances such as <anno data-annotation-id ="00000000 - 4000 - 4000 - 4000 - 8000 - 9000000000"></anno>,</anno>, and </anno>. In general, active metals react with concentrated sulfuric acid to form <anno data-annotation-id ="00000000 - 4000 - 4000 - 8000 - 8000 - 90000000000"> NO2 </anno>, dilute sulfuric acid to form <anno data-annotation-id ="0000000 - 4000 - 4000 - 9000 - 900000000000"> NO </anno>, and extremely dilute sulfuric acid to form <anno data-annotation-id ="20000a000000 - 90000000000"></anno></anno></anno>. For example, the reaction of calcium with different concentration of sulfuric acid: - \(Mg + 4HNO_3(16mol/L)=Mg(NO_3)_2+2NO_2↑+2H_2O\) - \(3Mg + 8HNO_3(6mol/L)=3Mg(NO_3)_2+2NO↑+4H_2O\) - \(4Mg + 10HNO_3(2mol/L)=4Mg(NO_3)_2+N_2O↑+5H_2O\) - \(4Mg + 10HNO_3(1mol/L)=4Mg(NO_3)_2+NH_4NO_3+3H_2O\) - \(5Mg + 12HNO_3(0.5mol/L)=5Mg(NO_3)_2+N_2↑+6H_2O\)。Moreover, the thinner the sulfuric acid was, the lower the valency of the nitrogen in the reduction product. However, it could not be mistaken that the dilute sulfuric acid had a stronger oxidisation ability than the concentrated sulfuric acid. In fact, the more concentrated the sulfuric acid was, the stronger the oxidisation ability was. - ** Special Metal Reaction **: Metal such as tin, stibine, and tungsten do not have much effect on nitrates. They may form an oxide-like substance that is not dissolved in nitrates, but they cannot form nitrates. 2. ** Reaction law of sulfuric acid and non-metals **: When sulfuric acid and non-metals react, it only shows the oxidisation property. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
1. ** Reaction of the same amount of metal with sufficient acid (horizontal coordinate is reaction time)** - Reaction rate relationship: When the same mass of Mn, and Mn react with a sufficient amount of the same acid of the same mass and concentration, the reaction rate relationship is: Mn> Mn. This was because under the conditions of a certain temperature, metal particle size, and solute mass fraction of the diluted acid solution, the stronger the mobility of the metal, the faster the reaction to produce hydrogen. - The mass relationship of the final hydrogen produced: The mass relationship of the final hydrogen produced is: 2. ** Reaction of the same amount of metal with sufficient acid (the horizontal coordinate is the mass of acid)** - When the same mass of Mn, and Mn reacted with a sufficient amount of sulfuric acid of the same mass and concentration, and the metals completely reacted, the mass relationship of the final hydrogen produced was: Mn> Mn. 3. ** Reaction of an equal amount of acid with a sufficient amount of metal (horizontal coordinate is reaction time)** - Reaction rate relationship: When the same acid with the same mass and concentration and sufficient amount of Mn, and Mn react sufficiently, the reaction rate relationship of hydrogen is: Mn> Mn. - The mass relationship of the final hydrogen produced: The mass relationship of the final hydrogen produced is: 4. ** Reaction of an equal amount of acid with a sufficient amount of metal (the horizontal coordinate is the mass of the metal)** - The mass relationship of the final hydrogen produced: When the same acid with the same mass and concentration and a sufficient amount of Mn, and Mn react sufficiently, the mass relationship of the final hydrogen produced is: Mn = Mn. When analyzing the image problem of the reaction between metal and acid, it was necessary to pay attention to the specific meaning of the ordinate and ordinate in the image. Generally, the ordinate was the amount of hydrogen produced, and the ordinate was usually time/s or the mass of acid consumed/g or the mass of metal consumed/g. At the same time, it was necessary to judge the amount of metal and acid. The amount of hydrogen produced in the reaction was determined by the amount of acid in the reaction. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
金属氧化物和稀硫酸反应会生成水和金属硫酸盐。例如: 1. 氧化镁与稀硫酸反应:\(MgO + H_{2}SO_{4} = MgSO_{4}+H_{2}O\)。 2. 氧化铁与稀硫酸反应:\(Fe_{2}O_{3}+3H_{2}SO_{4}=Fe_{2}(SO_{4})_{3}+3H_{2}O\)。 <a href="/?from=ask_words" style="color:red" target="_blank">点击前往免费阅读更多精彩小说</a>
The reaction between the two substances would produce a mixture of carbon dioxide and water. This reaction helped maintain the stability of the blood's pH. It had little effect on the blood's pH. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Under normal circumstances, the reaction between the two could not be carried out directly. Because the lone pair of electrons of the oxygen of the alcoholic group was coupled with the aromatic ring, the reaction activity was very weak, and it could not be used to catalyze the ester reaction with the acid. To synthesize the ester, the reaction of an acid acid or an acid ether with the ether was usually done. For example, the reaction between the ether and the ether was: C6H50H +(CH3CO) 2O = CH3COOC6H5 + CH3COON. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Cyclohexene was added to the acidic solution of sulfuric acid, which would undergo an oxidization reaction. The carbon-carbon double bond would be broken and then be oxided into a starch group. During the reaction, the purple color of the solution of sulfuric acid would disappear. This was because cyclohexene was an aromatic, which had a reducing property. The carbon-carbon double bond in it was easily oxided by the strongly oxidisable, acidic, and acidic potassium Permanganate. When the potassium Permanganate was reduced in the reaction, the Mn (7) ion was reduced to Mn (7) ions of other valences, so the color of the solution became lighter until it disappeared. The reaction equation was: 5C6H10 + 8KMnO4 + 12H2SO4 =5 (HOCC (CH2) 4COON)+4K2SO4 + 8MnSO4 + 12H2O. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
The reaction of sulfuric acid with different solutions was different: - During the reaction between the solution of sulfuric acid and the solution of the solution of - The acid reacted with rust (mainly composed of iron dioxide), dissolving and removing the rust. After the reaction, the solution turned yellow. - When sulfuric acid reacted with iron trioxid, reddish-brown floccule precipitations were dissolved to form a yellow solution; when sulfuric acid reacted with copper trioxid, blue precipitations were dissolved to form a yellow-green solution; when sulfuric acid reacted with copper dioxide, black solid was dissolved to form a yellow-green solution. - Gas was formed when the acid reacted with the metal, and it reacted with the metal. When the acid reacted with iron, the solution turned light green and released gas. When the acid reacted with aluminum, gas was formed. - When the solution is dropped into a solution (not specified) and vibrated while dropping, it may start to drop without any phenomenon. When a certain substance in the solution is basically transformed into another substance, gas will start to escape continuously (because the composition of the solution is not specified, only one possibility is provided). <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
The principle of the reaction between the two was that there was a lone pair of electrons in the nitrogen atom. When the nitrogen atom reacted with the acid, the lone pair of electrons of the nitrogen atom formed a coordination bond with the hydrogen ion in the acid to form an aminium salt. Take the reaction between hydrogen and hydrogen as an example. The reaction phenomenon is the production of a large amount of white smoke. The ion equation of the reaction was: [NH3 + H^+ = NH4 ^+]. From a microscopic point of view, the lone pair of electrons on the nitrogen atom in the nitrogen atom combined with hydrogen ions to form an amine ion. From a macro point of view, the reaction of the reaction of the formation of small white solid particles, dispersed in the air to form white smoke. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>