Understanding Heat and Phase Changes

What is the specific heat capacity of a substance?

• The amount of heat required to vaporize a substance.

• The amount of heat required to raise the temperature of 1 kg of a substance by 1 degree Celsius.

• The amount of heat required to change the phase of a substance.

• The amount of heat required to completely melt a substance.

What does a plateau on a heating curve indicate?

• An increase in kinetic energy.

• A phase change where temperature remains constant.

• A change in temperature.

• A decrease in potential energy.

Which equation is used to calculate the heat required for a phase change?

• Q = mcΔT

• Q = ml

• Q = mv

• Q = mt

How does evaporation differ from boiling?

• Evaporation occurs throughout the liquid, while boiling occurs only at the surface.

• Evaporation requires a specific temperature, while boiling can occur at any temperature.

• Evaporation occurs only at the surface, while boiling occurs throughout the liquid.

• Evaporation involves the formation of bubbles, while boiling does not.

What is evaporative cooling?

• The cooling effect when high-energy molecules escape from a liquid's surface.

• The process of heating a liquid to its boiling point.

• The process of condensation on a liquid's surface.

• The increase in temperature when a liquid evaporates.

What is the unit of specific latent heat?

• Joules per cubic meter

• Joules per kilogram

• Joules per liter

• Joules per second

Why does the temperature remain constant during a phase change?

• Because the heat is used to increase kinetic energy.

• Because the heat is used to break molecular bonds.

• Because the heat is lost to the surroundings.

• Because the heat is used to decrease potential energy.

What is the main difference between specific heat and latent heat?

• Specific heat is always larger than latent heat.

• Specific heat is measured in joules per liter, while latent heat is measured in joules per kilogram.

• Specific heat involves temperature changes, while latent heat involves phase changes.

• Specific heat involves phase changes, while latent heat involves temperature changes.

Which of the following requires more energy for water?

• Cooling water from 100 to 0 degrees Celsius

• Boiling water to steam

• Melting ice to water

• Heating water from 0 to 100 degrees Celsius

What happens to the potential energy during a phase change?

• It decreases.

• It remains constant.

• It increases.

• It fluctuates randomly.