Equilibrium Constants and Reactions

In this AP Chemistry video, Jeremy Kug covers unit 7 sections 2 and 3, focusing on reaction rates and equilibrium. He explains how the relative rates of forward and reverse reactions affect equilibrium positions. The video introduces the equilibrium constant (K), detailing its calculation using concentrations of products and reactants. An example problem demonstrates calculating KC for a reaction. Jeremy also explains how to write equilibrium constant expressions, emphasizing the exclusion of solids and liquids. Finally, the video discusses KP, the equilibrium constant for gases, and its relation to partial pressure.

What happens to the concentration of products if the forward reaction is faster than the reverse reaction?

• No change in concentrations

• More products than reactants

• Equal amounts of reactants and products

• More reactants than products

How is the equilibrium constant (K) calculated?

• Difference between reactants and products

• Reactants over products raised to the power of coefficients

• Products over reactants raised to the power of coefficients

• Sum of reactants and products

In the example problem, what is the concentration of ammonia at equilibrium?

• 0.010 M

• 1.98 M

• 3.50 M

• 0.31 M

Why do equilibrium constants have no units?

• The units cancel out during calculation

• They are always zero

• They depend on temperature

• They are dimensionless by definition

When writing equilibrium constant expressions, which states of matter should be omitted?

• Solids and gases

• All states of matter

• Gases and liquids

• Liquids and solids

What is the equilibrium constant expression for the reaction: 3 NO(g) → N2(g) + NO2(g)?

• KC = [NO2] / [N2][NO]^3

• KC = [N2][NO2]^3 / [NO]

• KC = [NO]^3 / [N2][NO2]

• KC = [N2][NO2] / [NO]^3

What is the significance of a large equilibrium constant value?

• More reactants than products at equilibrium

• More products than reactants at equilibrium

• Equal amounts of reactants and products

• No reaction occurs

What is KP used for in equilibrium expressions?

• Reactions involving solids

• Reactions involving liquids

• Reactions involving gases

• Reactions involving aqueous solutions

How does KP differ from KC?

• KP is for solids, KC is for gases

• KP uses concentrations, KC uses partial pressures

• KP is for liquids, KC is for solids

• KP uses partial pressures, KC uses concentrations

What should you use to express equilibrium constants for gaseous reactions?

• Molarity symbols

• Partial pressure symbols

• Concentration brackets

• Volume symbols