Equilibrium Expressions and Constants

The video tutorial explains the concept of heterogeneous equilibrium, where multiple phases exist at equilibrium. It discusses the role of pure liquids and solids, which do not appear in equilibrium constant expressions due to their fixed concentration. The tutorial demonstrates how to write equilibrium constant expressions in terms of concentrations and partial pressures, using examples involving aqueous solutions and gases. It highlights the importance of understanding these concepts for further studies in physical chemistry and thermodynamics.

What is a key characteristic of a heterogeneous equilibrium?

• It involves only one phase.

• It involves multiple phases.

• It involves only gases.

• It involves only liquids.

Why do pure liquids and solids not appear in the equilibrium constant expression?

• They are always in the gaseous phase.

• They have a fixed volume and concentration.

• Their concentration changes frequently.

• They have variable volumes.

What is the significance of the fixed volume of pure solids and liquids in equilibrium?

• It makes them volatile.

• It keeps their concentration constant.

• It changes their phase.

• It allows them to spread out.

How is the equilibrium constant expressed in terms of concentrations for the reaction involving carbon dioxide and carbon monoxide?

• Concentration of CO divided by concentration of CO2 squared.

• Concentration of CO2 divided by concentration of CO squared.

• Concentration of CO2 squared divided by concentration of CO.

• Concentration of CO squared divided by concentration of CO2.

How can equilibrium constants be expressed besides using concentrations?

• Using weights.

• Using volumes.

• Using partial pressures.

• Using temperatures.

In the context of equilibrium expressions, what is typically excluded when dealing with aqueous solutions?

• Aqueous reactants.

• All reactants.

• Gaseous reactants.

• Pure solids.

What happens to the equilibrium expression when pure solids are involved?

• They are doubled in the expression.

• They are excluded from the expression.

• They are included in the expression.

• They are halved in the expression.

When writing an equilibrium expression for a reaction involving sodium hydroxide and hydrogen gas, what is considered?

• Only the gaseous reactants.

• The concentration of sodium hydroxide and hydrogen gas.

• The concentration of pure solids.

• The partial pressure of sodium hydroxide.

Why might there be changes in equilibrium expressions when studying thermodynamics?

• Due to changes in concentration.

• Due to changes in temperature.

• Due to changes in pressure.

• Due to changes in phase.

What is the role of coefficients in equilibrium expressions involving sodium hydroxide and hydrogen gas?

• They are halved.

• They are doubled.

• They are not raised to any power.

• They are always squared.