Question

What is implied by the word constant in the term equilibrium constant? Give two reaction parameters that can be changed without changing the value of an equilibrium constant.

Short answer

The term 'constant' implies a fixed value at a given temperature. Reaction parameters like the presence of a catalyst and temperature can be changed without affecting the equilibrium constant.

Step-by-step solution

Understanding the Term 'Constant' in Equilibrium Constant

The term 'constant' in equilibrium constant implies that the value of the equilibrium constant (\(K_{eq}\)) remains unchanged at a given temperature. It is a fixed value that describes the ratio of concentrations of products to reactants when a chemical reaction is at equilibrium.

Effect of Temperature

One reaction parameter that can be changed without altering the equilibrium constant is temperature. Temperature changes can affect the rate at which equilibrium is reached, but the value of the equilibrium constant remains the same at a specific temperature.

Effect of Catalysts

Another reaction parameter that can be changed without changing the value of the equilibrium constant is the presence of a catalyst. Catalysts speed up the rate at which equilibrium is achieved but do not affect the equilibrium constant value.

Key concepts

chemical equilibrium

Chemical equilibrium is a state in a chemical reaction where the concentrations of reactants and products remain constant over time. One important thing to note is that this does not mean the reactants and products are in equal concentrations; it simply means their rates of formation are equal. This balance results in a stable mix as long as the system remains undisturbed. The equilibrium constant (K_{eq}) provides a snapshot of this balance by relating the concentrations of the products to the reactants at equilibrium.

reaction parameters

Reaction parameters are various conditions that can affect how a reaction proceeds and eventually reaches equilibrium.
Some key reaction parameters include:

• Concentration of Reactants and Products
• Pressure (especially for gaseous reactions)
• Volume
• Temperature
• Presence of Catalysts

By manipulating these reaction parameters, you can influence the rate of the reaction and how quickly it reaches equilibrium. However, not all parameters will change the equilibrium constant (K_{eq}).

catalysts

Catalysts are substances that increase the rate of a chemical reaction without being consumed in the process. They achieve this by lowering the activation energy required for the reaction to proceed. While a catalyst can help a reaction reach equilibrium faster, it **does not** change the equilibrium constant (K_{eq}). This means that the final balance of products and reactants remains the same, only achieved more rapidly.

temperature effect

Temperature plays a crucial role in chemical reactions and their equilibria. Changing the temperature of a system can affect both the reaction rate and the equilibrium position. However, the equilibrium constant (K_{eq}) is typically defined for a specific temperature. Once that temperature is set, K_{eq} remains constant. Thus, altering the temperature changes the speed but not the end state of equilibrium, unless the temperature changes significantly alter the kinetic energy and reaction pathways.