反应物和产物

当反应物分子之间的键断裂并在产物分子之间建立新键时，就会发生化学反应，从而产生新物质。

Chemical Reactions: When two or more molecules combine to generate a new product, it is called a chemical reaction.

反应物是结合形成新化合物的分子，而产物是形成的新化合物。化学反应在各种行业、习俗甚至我们的日常生活中都很重要。化学变化必须发生在化学反应中，这在物理变化中很常见，如降水、产热、颜色变化等。

两个原子、离子或分子之间可以发生反应，它们在其中形成新键而不会破坏或产生原子，但反应物会形成新产物。压力、温度和反应物浓度都对反应速率有影响。

Chemical Equations: As there are so many chemical reactions all around us, a nomenclature was created to make expressing a chemical reaction in the form of a chemical equation easier. A chemical equation is a mathematical statement that represents the production of a product from reactants while also indicating the conditions under which the reaction was carried out. 

反应物在左边，产物在右边，用单头或双头箭头连接它们。考虑一个反应。

A + B → C + D

这里，

• A和B是反应物，并且
• C和D是它们反应的产物。

反应物在化学方程式中通过它们的化学式来识别。必须平衡化学方程式以确保质量守恒定律，这意味着两侧的原子数必须相等。这是平衡方程的方法。

化学反应的两个主要成分是反应物和产物。反应物是引发化学反应的物质。反应完成后可以检测到的化学物质称为产物。化学反应分为三种类型：酸碱反应、氧化还原反应和燃烧反应。

因此，根据反应的种类，同一种反应物有时可能会产生多种产物。反应物和产物之间的主要区别在于，反应物在反应过程中被消耗，而产物是反应的结果。

什么是反应物？

Reactants are chemical species that serve as the catalyst in a chemical reaction. During the course of a chemical reaction, reactants are consumed. 

在反应结束时，反应混合物中可能不存在任何反应物，尽管最后可能存在一些反应物。

可以存在无色或有色反应物。根据反应的性质和环境，它们可以产生无色或有色化合物。化学反应的反应物可能以固相、液相或气相存在。反应物因反应类型而异。

反应类型和反应物

• 燃烧反应：燃烧反应产生的反应物是极易燃的化学物质。
• 分解反应：分解反应中的反应物是比反应产物更大的分子。
• 酸碱反应：酸和碱是这些反应中的反应物。
• 氧化还原反应：氧化剂和还原剂是反应物。有时使用缓冲溶液来保持反应混合物的 pH 值稳定。
• 合成反应：合成过程使用比产品更小的分子作为反应物。
• 沉淀反应：沉淀反应的反应物通常是液体。
• 放热反应：这些化学过程中反应物的势能大于产物的势能。
• 吸热反应：这些反应中反应物的势能低于产物的势能。

什么是产品？

Products are substances that are created as a result of a chemical reaction. These byproducts may be ions or molecules. The result of a chemical reaction might exist in the solid, liquid, or gaseous phases.

提供无色或多色产品。结果的颜色由反应中使用的反应物类型决定。反应混合物中存在的产物数量总是随着反应的进行而增加。

反应和产物的类型

• 燃烧反应：对于完全燃烧（碳氢化合物），燃烧反应的产物通常是二氧化碳和水，部分燃烧的一氧化碳。
• 分解反应：分解过程的产物是比反应物更小的分子。
• 酸碱反应：这些反应总是会产生盐和水作为副产品。
• 氧化还原反应：产物是反应物的氧化形式和反应物的还原形式。水经常被用作产品。
• 沉淀反应：沉淀反应产生固体沉淀物或悬浮液。
• 合成反应：合成反应产生比反应物更大的分子。
• 放热反应：这些化学反应产物的势能低于反应物的势能。
• 吸热反应：这些反应的产物比反应物具有更高的势能。

反应物和产物的例子

在一个反应中，反应物是你开始的。它们与您在反应发生后得到的不同。任何化学反应都涉及反应物和产物。

1. 蜡烛的蜡和空气中的氧气是燃烧反应中的反应物。二氧化碳和水蒸气是副产品。
2. 当甲烷气体燃烧时，反应物是甲烷（CH ₄ ）和空气中的氧气（O ₂ ）。该反应产生二氧化碳（CO ₂ ）和水（H ₂ O）。
3. 形成水的反应物是氢气 (H2) 和氧气 (O ₂ )。水是产物（H ₂ O）。
4. 二氧化碳 (CO ₂ ) 和水是光合作用 (H ₂ O) 中的反应物。葡萄糖是产物（C ₆ H ₁₂ O ₆ ）。应该注意的是，阳光不是反应物。反应物是物质（原子、分子和离子）而不是能量。

Identifying Reactants and Products in Chemical Equations

To identify the reactants and products in a chemical equation, look at the reaction arrow. The arrow points from left to right in a reaction that only proceeds forward. The reactants are on the left side of the arrow, while the products are on the right. A chemical species that appear on both sides of a reaction (such as solvent or spectator ions) is neither a reactant nor a product. In the following reaction, A and B are reactants, and C is the product:

A + B → C

There does not, however, have to be more than one reactant. A is the reactant in this reaction, while B and C are the products:

A → B + C

In a balanced chemical equation, the number and type of atoms are the same for the products and the reactants. For example, the number of hydrogen and oxygen atoms in the reactants (H₂ and O₂) and the product is the same (H₂O).

反应物和产物之间的区别

Reactants	Products
Chemical reactants are the starting element for a chemical reaction.	Products are the byproducts of chemical reactions.
Reactants are consumed throughout the process.	The reaction’s products are not absorbed.
During the response, the quantity of reactants in the reaction mixture decreases quickly or slowly.	The quantity of products present in the reaction mixture increases rapidly or gradually.
At the start of the reaction, only reactants are present.	At the start of the reaction, no products emerge in the reaction mix.
At the end of the reaction, reactants may or may not be present in the solution combination.	At the end of the reaction, the products are discovered in the solution blend.

示例问题

问题1：化学反应是什么意思？

回答：

A chemical reaction occurs when two or more molecules collide with the proper orientation and enough force to form a new product. This process involves the breaking and forming of atom bonds. Compounds that interact to form new compounds are referred to as reactants, while the newly formed compounds are referred to as products.

问题2：什么是电解分解？

回答：

Electrolytic decomposition is the process of decomposing any molecule using electricity. This is useful when we need to separate molecules that dissociate at high temperatures. Sodium chloride is one such example. Sodium chloride dissociates at high temperatures but easily breaks apart during electrolytic decomposition.

问题3：单位移和双位移反应的区别？

回答：

A single displacement reaction occurs when one or more elements in a compound replace another element. A double displacement reaction, on the other hand, involves two ion exchanges between compounds, resulting in the formation of two new compounds.

问题4：我们如何平衡化学方程式？

回答：

• Make a note of the unbalanced chemical reaction. If the unbalanced chemical reaction is not given, write down the skeletal equation using the components of the chemical reaction that are mentioned.
• Take note of how many atoms are on each side of each element’s reaction. The number of atoms is represented by an element’s subscript. If the number of atoms on the reactant side is not equal to the number of atoms on the product side, the equation is not balanced. Because this violates the law of conservation of mass, we must balance the chemical reaction.
• In the chemical reaction, add coefficients to the compounds or elements so that the number of atoms on both sides of the reaction matches for all constituent elements. Keep in mind that oxygen and hydrogen atoms should be balanced last because they are present in a variety of compounds and trying to fix that ratio first will complicate things even more.

问题5：反应物和试剂有什么区别？

回答：

Reactant and reagent are terms that are frequently used interchangeably. Technically, the two words do not have the same meaning. In analytical chemistry, a reagent is a substance that is added to cause a chemical reaction or to test whether one has occurred. Reagents are not always consumed in a reaction. Although solvents, catalysts, and substrates may be present in a reaction, they are not considered reactants or products.