The Determination of a Rate Equation

Purpose of Determining the Speed ​​Equation - The purpose of this experiment is to develop a method to determine the rate equation of the reaction between magnesium band and 0 mol dm HCl HCl. Hypothesis and theory --------------------- When using the magnesium reaction to react with magnesium, they react according to the following formula. Mg (s) + 2 HCl (Aq) → MgCl (aq) + H (g) For the reaction to succeed, the molecule collides with sufficient kinetic energy to overcome the energy barrier, also known as activation energy There must be.

The kinetic or kinetic equation of the chemical reaction is a differential equation that relates the reaction rate to the reactant concentration or pressure and constant parameters (usually rate coefficient and partial reaction order). In order to determine the velocity equation for a particular system, the reaction rate can be combined with the mass balance of the system. Furthermore, there are a series of differential equations for the study of thermodynamics and quantum mechanics.

In these formulas, k (T) is the reaction rate coefficient or reaction rate constant. However, it is not actually a constant because it contains all the parameters affecting the reaction rate, except for the concentrations explicitly considered. Among all parameters affecting the reaction rate, temperature is usually the most important parameter and is calculated by the Arrhenius equation. The indices n and m are called reaction orders and depend on the reaction mechanism. In a basic (single step) reaction, the order of each reactant is equal to its stoichiometric coefficient. However, for complex (multi-stage) reactions this is usually inaccurate and the rate equation is determined by a detailed mechanism, as shown by the reaction to H 2 and NO as follows.

These are called Michaelis - Menten equations. Here, Vmax represents the maximum initial reaction rate, and Km represents the Michaelis constant. Km shows an initial reaction rate of 1 / 2Vmax. This equation is basically a hyperbolic function that proves saturation phenomena. This formula is derived based on specific assumptions (see "Derived" column on page 55) and is not always applied to all enzymatic reactions. In practice, however, this formula is applicable to many enzymatic reactions and Km is used as an indicator of the affinity between the enzyme and the substrate (the smaller the Km, the greater the affinity).