Thermodynamics and Phase Changes

The video tutorial explains the concept of enthalpy in relation to phase changes, focusing on the transitions between solid, liquid, and gas states. It covers the enthalpy of fusion for melting, the enthalpy of vaporization for evaporation, and the exothermic nature of condensation. The tutorial emphasizes the energy required for these transitions and the differences between endothermic and exothermic processes.

What is the process called when a solid turns into a liquid?

• Sublimation

• Evaporation

• Condensation

• Melting

How much energy is required to melt one mole of ice?

• 10.5 kJ/mol

• 6.01 kJ/mol

• 40.7 kJ/mol

• 15.2 kJ/mol

What is the term for the transition from liquid to gas?

• Condensation

• Fusion

• Evaporation

• Freezing

How much energy is needed to vaporize one mole of water?

• 6.01 kJ/mol

• 20.5 kJ/mol

• 40.7 kJ/mol

• 15.2 kJ/mol

What happens to energy during condensation?

• Energy is released

• Energy is absorbed

• Energy remains constant

• Energy is doubled

Which of the following is an exothermic process?

• Sublimation

• Condensation

• Melting

• Evaporation

What does an endothermic reaction involve?

• No heat change

• Absorption of heat

• Release of heat

• Doubling of heat

What sign is used for enthalpy change in an exothermic reaction?

• Undefined

• Zero

• Negative

• Positive

How do you determine the enthalpy change for a gas to liquid transition?

• Use the vaporization value with a positive sign

• Use the melting value

• Use the fusion value

• Use the vaporization value with a negative sign

What is the enthalpy change for vaporization of water?

• 6.01 kJ/mol

• 40.7 kJ/mol

• 20.5 kJ/mol

• 15.2 kJ/mol