Equilibrium Reactions and Constants

The video tutorial covers Chapter 18, Section 1, focusing on the nature of chemical equilibrium. It begins with an introduction to reversible reactions and the concept of equilibrium, where opposing reactions balance out. The tutorial explains how equilibrium is reached when the rates of forward and reverse reactions are equal, resulting in constant concentrations of reactants and products. The video also discusses the equilibrium constant (K), its calculation, and its significance in determining the favorability of products or reactants. Examples are provided to illustrate the calculation of K and its application in chemical reactions.

What is the main characteristic of a reversible reaction?

• It stops once equilibrium is reached.

• It can proceed in both forward and reverse directions.

• It only occurs in open systems.

• It only proceeds in one direction.

When a reaction is said to 'lie to the right', what does it mean?

• The reaction is irreversible.

• The reaction is at equilibrium.

• The products are favored.

• The reactants are favored.

What happens to the reaction rates of A and B as they form C and D over time?

• The reaction rate of A and B increases.

• The reaction rate of A and B decreases.

• The reaction rate of C and D decreases.

• The reaction rate of C and D remains constant.

What does a large equilibrium constant (K) indicate about a reaction?

• The reaction favors the reactants.

• The reaction favors the products.

• The reaction is irreversible.

• The reaction is slow.

How is the equilibrium constant (K) determined?

• By observing the color change of the reaction.

• Through theoretical calculations.

• By measuring the concentrations at equilibrium.

• By calculating the reaction rate.

In the equilibrium expression, what do the exponents represent?

• The temperature of the reaction.

• The coefficients from the balanced equation.

• The initial concentrations of reactants.

• The speed of the reaction.

What is the significance of a unitless equilibrium constant?

• It acts as a constant of proportionality.

• It shows the reaction is at equilibrium.

• It means the reaction is spontaneous.

• It indicates the reaction is irreversible.

In the example of hydrogen iodide formation, what is squared in the equilibrium expression?

• The concentration of hydrogen iodide.

• The concentration of water.

• The concentration of iodine.

• The concentration of hydrogen.

What is the first step in solving for the concentration of a product using the equilibrium constant?

• Measure the temperature.

• Rearrange the equilibrium expression.

• Determine the initial concentrations.

• Calculate the reaction rate.

What does a low equilibrium constant (K) suggest about the reaction?

• The reaction is fast.

• The reaction is at equilibrium.

• The reaction favors the products.

• The reaction favors the reactants.