Heating Curves and Energy Changes Quiz

What is the term used to describe the change in heat energy when pressure is constant?

• Thermal Conductivity

• Entropy

• Enthalpy

• Specific Heat

During which phase change does the temperature of a substance remain constant?

• Gas to Solid

• Both Solid to Liquid and Liquid to Gas

• Solid to Liquid

• Liquid to Gas

Which equation is used to calculate energy change during a temperature change within a phase?

• Heat of Fusion times Moles

• Mass times Specific Heat times Temperature Change

• Heat of Vaporization times Moles

• Pressure times Volume Change

What is the specific heat of water in joules per gram per degree Celsius?

• 3.5 J/g°C

• 1.0 J/g°C

• 4.184 J/g°C

• 2.1 J/g°C

What is the total enthalpy change for 10 grams of water when heated from -20°C to +50°C?

• 7852 J

• 6852 J

• 5852 J

• 4852 J

In the example problem with water, what is the first step in calculating the enthalpy change?

• Calculate the heat of vaporization

• Calculate the heat of fusion

• Calculate the energy change using specific heat of ice

• Calculate the energy change using specific heat of liquid water

What is the boiling point of paradichlorobenzene in the example problem?

• 200°C

• 100°C

• 123°C

• 80°C

In the paradichlorobenzene example, what happens at 123°C?

• The substance melts

• The substance boils

• The gas condenses to liquid

• The liquid freezes

What is the total enthalpy change for 10 grams of paradichlorobenzene when cooled from 200°C to 80°C?

• 3658.4 J

• 4658.4 J

• 1658.4 J

• 2658.4 J

What is the nature of the enthalpy change when paradichlorobenzene is cooled from 200°C to 80°C?

• Isothermal

• Adiabatic

• Exothermic

• Endothermic