Understanding Reaction Quotients and Equilibrium

The video tutorial explains the concept of the reaction quotient (Q) and its role in determining whether a chemical reaction is at equilibrium. It demonstrates how to calculate Q using a hypothetical reaction and compares it with the equilibrium constant (K) to predict the direction of the reaction. The tutorial also covers scenarios where Q is less than, equal to, or greater than K, and how these affect the reaction's progress towards equilibrium. An example involving the decomposition of phosgene is used to further illustrate these concepts.

What does the reaction quotient (Q) indicate about a chemical reaction?

• The speed of the reaction

• The temperature of the reaction

• The color of the reactants

• Whether the reaction is at equilibrium

In the hypothetical reaction, what is the equilibrium constant (K) at 25°C?

• 4

• 2

• 3

• 1

How is the concentration of a substance determined from a particulate diagram?

• By counting the number of particles

• By observing the color change

• By weighing the particles

• By measuring the temperature

If Qc is less than K, in which direction will the reaction proceed?

• To the left, forming more reactants

• To the right, forming more products

• It will stop

• It will reverse

What happens to the number of blue particles as the reaction progresses towards equilibrium?

• They decrease

• They remain constant

• They disappear

• They increase

When Q is greater than K, what does this indicate about the reaction?

• The reaction is at equilibrium

• There are too many products

• There are too many reactants

• The reaction is too slow

What is the net reaction direction when Q is greater than K?

• It speeds up

• To the right, forming more products

• To the left, forming more reactants

• It remains unchanged

In the decomposition of phosgene, what is the equilibrium constant (K) at 100°C?

• 2.2 x 10^-10

• 1.0 x 10^-8

• 6.0 x 10^-6

• 3.4 x 10^-6

What is the concentration of carbon monoxide used in the phosgene decomposition example?

• 3.4 x 10^-6 M

• 2.0 x 10^-3 M

• 6.0 x 10^-6 M

• 1.0 x 10^-8 M

What does a Qc value of 1.0 x 10^-8 indicate in the phosgene decomposition reaction?

• Qc is zero

• Qc is less than K

• Qc is equal to K

• Qc is greater than K