Phase Changes Practice
10 problems · instant feedback · full explanations
During a phase change, added heat breaks bonds instead of raising temperature — Q = mL. Temperature plateaus while phases coexist.
Q1.
The heat needed per kilogram to change phase at constant temperature is:
Multiple choice · Easy
Q2.
How much heat melts 0.2 kg of ice at 0 °C? (Lf = 334 kJ/kg.)
Numerical answer (J) · Medium
Q3.
Why does temperature stay constant while ice melts?
Multiple choice · Easy
Q4.
Which phase change has the larger latent heat for water?
Multiple choice · Medium
Q5.
How much heat vaporizes 0.5 kg of water at 100 °C? (Lv = 2.26×10⁶ J/kg.)
Numerical answer (J) · Hard
Q6.
How much ice at 0 °C can 167,000 J of heat melt? (Lf = 334 kJ/kg. Answer in kg.)
Numerical answer (kg) · Medium
Q7.
At high altitude (lower air pressure), water's boiling point:
Multiple choice · Hard
Q8.
A heating curve has flat segments where phase changes occur.
True / False · Easy
Q9.
Deposition is the phase change from solid directly to gas.
True / False · Medium
Q10.
A weighted wire slowly cuts through an ice block without splitting it. This demonstrates:
Multiple choice · Hard