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Rate of reaction 反應速率 Brian Sir 教學重溫

Question: Rate of reaction in chemistry, what are the requirement for a chemical reaction to occur? what are the factors that can change the rate of reaction?

Answer: 答案: 化學反應的速率,發生化學反應需要什麼樣的條件?有哪些因素可以改變反應的速率? 答案是,為了使化學反應發生,必須滿足以下條件︰一、活性物質。二、必須形成新物質。三、要有熱力學允許。 另外,以下因素可以影響反應的速率︰一、濃度:反應速率與濃度有關,濃度越高,反應速度越快。二、溫度:溫度越高,反應速度越快。三、粉碎程度:反應物越細小,表面積越大,反應速度越快。四、催化劑:催化劑可以加速反應的速率,同時不會被消耗。五、反應物之間的作用促進反應的速率。

For a chemical reaction to occur, there must be a supply of reactants and the right conditions. The main requirements for a chemical reaction to take place are the presence of reactants, a catalyst, heat or pressure, and the correct pH level. The rate of reaction is affected by several factors that can be divided into two main categories: physical factors and chemical factors. Physical factors include temperature, surface area of the reactants, and the concentration of the reactants. Raising the temperature speeds up the chemical reaction, while increasing the surface area of the reactants increases the number of collisions between the particles. The concentration of the reactants also has an effect, as a more concentrated solution will increase the likelihood of successful collisions. Chemical factors include the type of catalysts used and the activation energy. A catalyst helps reduce the activation energy, which is the amount of energy required to start a reaction. The specific configuration of atoms involved in the reaction, referred to as the reaction mechanism, also affects the rate of reaction. Therefore, the requirements for a chemical reaction to occur are a supply of reactants, the right conditions, a catalyst, heat and/or pressure, and the correct pH level. Additionally, physical and chemical factors influence the rate of reaction, such as temperature, surface area, concentration, type o

化学反应速率,化学反应发生需要什么条件?什么因素可以改变反应速率? 一个化学反应发生,必须满足以下三个基本要素:气体,温度和激发性事件。其中气体是必需的,当反应物在气体中分解时,必须有相应的气体的参与。温度是很重要的一个因素,它与反应的微观机理有很大的关系。通常情况下,当温度升高时,反应速率也会相应增加。激发性事件又称作分子撞击,是指在一定的温度下,在一段时间内,反应物之间会发生撞击,这样才能使化学反应发生,改变反应速率。 此外,反应物之间的浓度、存在物质的种类和形式以及反应物与反应物之间的竞争等均会影响反应速率。在反应物之间存在一定浓度的情况下,反应速率会升高;而当多种反应物在反应中参与时,在反应过程中产生的产物会和单质参与反应过程,反应速率也会随之变化。最后,反应物间竞争会影响反应速率,如果当反应物之间存在竞争,那么反应速率会相应下降。