# Relationship between equilibrium constant and rate

### Relationship between equilibrium constant and rate constants

The equilibrium constant, K, can be used to find the concentrations of each component of a reversible Relationship between Kp and Kc. Presents an approach used with an apparatus to demonstrate quantitatively the relationship between rate constants and the equilibrium constant for simple. To know the relationship between the equilibrium constant and the rate involving the equilibrium between gaseous water and its elements.

The equation is a function of the concentrations, the upper case letters are the molar concentrations of the reactants and products A, B etc.

The lowercase letters are the stoichiometric coefficients that balance the equation. Kp For equilibria in the gas phase, the equation is a function of the reactants and products Partial Pressures.

### Relationships Involving Equilibrium Constants - Chemistry LibreTexts

The Equilibrium Constant is expressed as: Relationship between Kp and Kc The equilibrium constants Kpand Kc can easily be related by the following equation: T represents the temperature in Kelvin K at which the equilibrium reaction takes place. Example 1 For the following balanced chemical reaction: Knowing the Kc value for the above reaction is It does not include solids or liquids.

Relationship Between Equilibrium Constants

The concentrations of pure solids and pure liquids are treated as one for these substances, so they do not affect the equilibrium constant. Assumptions about the Reaction Based on the Value of K When we know the numerical value of the equilibrium constant, we can make certain judgments about the extent of the chemical reaction.

Changing K when Changing the Balanced Equation Since the value of K is dependent on the chemical reaction, when the balanced chemical equation is manipulated in any way, the value of K changes accordingly. Take, for example, the chemical equation listed below: If this equation were to be reversed: Take again the reaction listed below: If you decided to alter the equation so 4 moles of SO3 are produced instead of 2: Let's start with the rate law for a reaction that is first-order in the disappearance of a single reactant, X.

When this equation is rearranged and both sides are integrated we get the following result.

Integrated form of the first-order rate law: In this equation, X is the concentration of X at any moment in time, X 0 is the initial concentration of this reagent, k is the rate constant for the reaction, and t is the time since the reaction started.

To illustrate the power of the integrated form of the rate law for a reaction, let's use this equation to calculate how long it would take for the 14C in a piece of charcoal to decay to half of its original concentration.

We will start by noting that 14C decays by first-order kinetics with a rate constant of 1. The integrated form of this rate law would be written as follows.

### The Equilibrium Constant, K - Chemistry LibreTexts

We are interested in the moment when the concentration of 14C in the charcoal is half of its initial value. Substituting this relationship into the integrated form of the rate law gives the following equation.

• The Equilibrium Constant, K
• 15.3: Relationships Involving Equilibrium Constants
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We now simplify this equation and then solve for t. It therefore takes years for half of the 14C in the sample to decay.

This is called the half-life of 14C. In general, the half-life for a first-order kinetic process can be calculated from the rate constant as follows.