Chapter 10 Chemical Equilibrium

University:
Kentucky State University
Course:
CHE 101 | General Chemistry I
Academic year:

2021
Views:

240

Pages:

1
Author:

helyettitycx1

Chapter 10: Chemical Equilibrium - In some reactions no product is formed to allow the reaction to go to completion; the reactants and products can still interact in both directions. 𝐴+𝐵 ⇆ 𝐶+𝐷 - The double arrow indicates that C and D can react to form A and B, while A and B react to form C and D. EFFECTS OF CHANGING CONDITIONS Effect of Changing the Concentrations - When a system at equilibrium is disturbed by adding or removing one of the substances, all the concentrations will change until a new equilibrium point is reached with the same value. - If the concentration of a reactant in the forward reaction is increased, the equilibrium is shifted to the right, favoring the forward reaction. - If the concentration of a reactant in the reverse reaction is increased, the equilibrium is displaced to the left. - Decreases in concentration will produce effects opposite to those produced by increases. Effect of Temperature on Equilibrium - If the temperature of a given equilibrium reaction is changed, the reaction will shift to a new equilibrium point. - If the temperature of a system in equilibrium is raised, the equilibrium is shifted in the direction that absorbs heat. Effect of Pressure on Equilibrium - If it is assumed that the total space in which the reaction occurs is constant, the pressure will depend on the total number of molecules in that space. - An increase in the number of molecules will increase pressure; a decrease in the number of molecules will decrease pressure. - if the pressure is increased, the reaction that will be favored is the one that will lower pressure or decrease the number of molecules. Ex: 𝑁2 (𝑔) + 3𝐻2 (𝑔) → 2𝑁𝐻3 (𝑔) + ℎ𝑒𝑎𝑡 (𝑎𝑡 𝑒𝑞𝑢𝑖𝑙𝑖𝑏𝑟𝑖𝑢𝑚) - If the concentrations of the nitrogen and hydrogen are increased, the forward reaction is increased. - If the ammonia produced is removed by dissolving it in water, the forward reaction is again favored. - b/c the reaction is exothermic, the addition of heat must be accounted for. - Increasing the temperature causes an increase in molecular motion and collisions thus allowing the product to form more readily. - An increase in pressure will cause the forward reaction to be favored since the equation shows that four molecules of reactants are forming two molecules of products.