Heating Curves and Energy Changes Quiz

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

• Entropy

• Enthalpy

• Energy

• Temperature

During which phase change does the temperature remain constant?

• Both solid to liquid and liquid to gas

• Gas to solid

• Liquid to gas

• Solid to liquid

What is the specific heat of water in joules required to raise the temperature of 1 gram by 1 degree Celsius?

• 2.1 J/g°C

• 4.184 J/g°C

• 1.0 J/g°C

• 3.5 J/g°C

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

• Heat of phase change times number of moles

• Mass times specific heat times temperature change

• Pressure times volume change

• Mass times velocity squared

What happens to the energy during the melting phase of a substance?

• It remains constant

• It decreases potential energy

• It increases kinetic energy

• It is used to break attractive forces

Which part of the heating curve involves using the specific heat of the liquid?

• Boiling

• Solid heating

• Melting

• Liquid heating

In the example problem, what is the total enthalpy change for 10 grams of water from -20°C to +50°C?

• 4852 J

• 5852 J

• 6852 J

• 7852 J

What is the significance of drawing a graph when solving enthalpy change problems?

• It is only useful for water-related problems

• It eliminates the need for calculations

• It provides exact numerical answers

• It helps visualize phase changes

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

• 4658.4 J

• 2658.4 J

• 1658.4 J

• 3658.4 J

What type of process is it when heat is lost during cooling?

• Adiabatic

• Isothermal

• Exothermic

• Endothermic