Learning Goal
Phase Change and Latent Heat
Teacher tools for this standard
Lesson Plan · Guided Notes · Exit Ticket · Re-teach · Homework
Teacher tools for this standard
Lesson Plan · Guided Notes · Exit Ticket · Re-teach · Homework
- Lesson Plan →Objectives, pacing and practice, built from this lesson's brief.
- Guided Notes →One page your students fill in and keep.
- Exit Ticket →Three items at the end of class. No student accounts.
- Re-teach →After an exit ticket: who missed what, and what to do tomorrow.
- Homework →Assign practice; it grades itself.
"Instead, the additional thermal energy acts to loosen bonds between molecules or atoms and causes a phase change. Because this energy enters or leaves a system during a phase change without causing a temperature change in the system, it is known as latent heat (latent means hidden)."
"The heat, Q, required to change the phase of a sample of mass m is Q = mL_f (for melting/freezing), Q = mL_v (for vaporization/condensation), where L_f is the latent heat of fusion, and L_v is the latent heat of vaporization."
"The ice starts out at −20 °C, and its temperature rises linearly, absorbing heat at a constant rate until it reaches 0°. Once at this temperature, the ice gradually melts, absorbing 334 kJ/kg. The temperature remains constant at 0 °C during this phase change. ... At 100 °C, the water begins to boil and the temperature again remains constant while the water absorbs 2256 kJ/kg during this phase change."
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"Instead, the additional thermal energy acts to loosen bonds between molecules or atoms and causes a phase change. Because this energy enters or leaves a system during a phase change without causing a temperature change in the system, it is known as latent heat (latent means hidden)."
"The heat, Q, required to change the phase of a sample of mass m is Q = mL_f (for melting/freezing), Q = mL_v (for vaporization/condensation), where L_f is the latent heat of fusion, and L_v is the latent heat of vaporization."
"The ice starts out at −20 °C, and its temperature rises linearly, absorbing heat at a constant rate until it reaches 0°. Once at this temperature, the ice gradually melts, absorbing 334 kJ/kg. The temperature remains constant at 0 °C during this phase change. ... At 100 °C, the water begins to boil and the temperature again remains constant while the water absorbs 2256 kJ/kg during this phase change."
What you'll learn
- Describe the four phases of matter at the particle level and the transitions between them
- Explain why temperature stays constant during a phase change
- Define and distinguish the latent heat of fusion and the latent heat of vaporization
- Apply Q = mL_f and Q = mL_v to calculate the heat for a phase change
- Solve multi-step problems that combine temperature changes (Q = mcΔT) and phase changes (Q = mL), including heat-balance problems
Slides
Step through the lesson, or watch it as a narrated video
Slides
In development
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