The best examples of phase change experiments: 3 practical examples you can actually do

When teachers ask for the best examples of phase change experiments: 3 practical examples that actually work in a crowded classroom, this one always makes the list: measuring how ice melts and water freezes while tracking temperature over time.

At first glance, it looks too simple. Ice cubes in a beaker, a thermometer, a stopwatch. But this basic setup can reveal a lot:

• How temperature stays nearly constant during a phase change
• How latent heat of fusion works in real life
• Why adding salt to ice changes the melting point

Core example of a melting–freezing phase change experiment

Set up a beaker half-filled with crushed ice and just enough water to make good contact with a thermometer probe. Use a digital thermometer or simple temperature probe connected to a data logger or laptop. Start at a temperature below 32 °F (0 °C) if possible, then record temperature every 30–60 seconds as the ice warms and melts at room temperature.

What students see:

• The temperature rises up to about 32 °F (0 °C)
• Then it stalls at that temperature while the ice melts
• Only after most of the ice has melted does the temperature begin to rise again

This is a clean, visual example of energy going into changing phase rather than raising temperature. It’s also a straightforward way to introduce the idea of latent heat without heavy math.

Variation 1: Salt, ice, and super-chilled water

To push this further, repeat the experiment with salt mixed into the ice. Road crews and city planners have been using this chemistry trick for decades to keep streets passable in winter, and it’s one of the most relatable real examples you can offer students.

Procedure tweak:

• Mix about 1–2 tablespoons of table salt per cup of crushed ice
• Stir and insert the thermometer
• Record how low the temperature drops (often down to about 14 °F / −10 °C or lower)

Now students see that the freezing point of water is not some untouchable constant; it shifts with dissolved substances. That makes it one of the best examples of how phase changes connect to real-world applications like road salting, homemade ice cream, and antifreeze in car engines.

For background on freezing point depression and colligative properties, you can point students to open chemistry resources from universities such as MIT OpenCourseWare or similar .edu sites.

Variation 2: Measuring latent heat (for advanced classes)

If you want a more quantitative example of phase change experiments, you can estimate the latent heat of fusion of ice using a simple calorimetry setup:

• Start with a known mass of warm water in an insulated container (like a foam cup)
• Measure its initial temperature
• Add a known mass of ice at 32 °F (0 °C)
• Stir until all the ice melts and measure the final temperature

From the energy lost by the warm water (using \( q = mc\Delta T \)), students can estimate the energy absorbed by the melting ice. This gives a numerical value for the latent heat of fusion, which they can compare to reference values from sources such as the National Institute of Standards and Technology (NIST) at nist.gov.

This variation turns a simple ice cube into a full-fledged thermodynamics lab.

2. Boiling and condensation: from kitchen kettle to lab-grade heating curve

If the first experiment owns freezing and melting, the second of our examples of phase change experiments: 3 practical examples takes on boiling and condensation. You can run it with a hot plate and beaker, or with a basic electric kettle and a safe way to measure temperature.

Core example of a boiling water phase change experiment

Fill a beaker with tap water and place it on a hot plate. Insert a thermometer or temperature probe and start heating. Record temperature every 30–60 seconds from room temperature up through boiling.

Students will observe:

• A steady temperature increase at first
• A plateau as the water reaches its boiling point (around 212 °F / 100 °C at sea level)
• Violent bubbling while the temperature stays nearly constant

Again, this is a textbook example of energy going into phase change (liquid to gas) instead of raising temperature. The resulting heating curve has the same plateau behavior they saw with melting ice, reinforcing the concept across two different phase changes.

For an international audience, it’s worth pointing out that the boiling point shifts with atmospheric pressure. The U.S. National Weather Service at weather.gov and the National Center for Atmospheric Research at ucar.edu both provide accessible explanations of how pressure changes with altitude.

Variation 3: Condensation on a cold surface

To bring condensation into the picture, hold a chilled metal spoon or glass plate above the steam (without touching the boiling water). Very quickly, water droplets will form on the cold surface.

This gives you:

• A visible example of gas turning back into liquid
• A chance to talk about energy release during condensation
• A bridge to real examples like cloud formation, rain, and dew on grass

You can extend this into a mini “water cycle in a beaker” demonstration by covering the beaker with a cool glass plate and letting droplets form and fall back, mimicking rainfall.

Variation 4: Boiling point and elevation (data-rich, no travel required)

In 2024–2025, it’s easier than ever to pull real environmental data into class. You don’t have to haul students to Denver or Mexico City to talk about boiling point changes with altitude. Instead, you can:

• Look up recorded atmospheric pressure and elevation for several U.S. cities using data from NOAA.gov
• Have students predict how the boiling point of water changes with elevation
• Compare their predictions to published boiling point tables from university chemistry departments (for example, many .edu sites host these charts)

Even if you only physically boil water at one location, this becomes a data-based example of how phase changes are sensitive to environmental conditions. It also connects nicely to cooking instructions on food packages that mention “high-altitude directions,” a very real example students may have seen at home.

3. Sublimation, deposition, and supercooling: the “wow” side of phase changes

The third of our examples of phase change experiments: 3 practical examples moves beyond the everyday and into the slightly more dramatic: sublimation (solid to gas) and supercooling (liquid cooled below its freezing point without solidifying). These are the experiments that tend to stick in students’ memories.

Core example of sublimation: dry ice in the classroom

Dry ice (solid carbon dioxide) is a classic example of sublimation. At normal atmospheric pressure, it doesn’t melt into liquid; it goes straight from solid to gas.

A simple setup:

• Place a small chunk of dry ice in a clear, open container
• Observe the fog-like cloud that forms as cold CO₂ gas chills the surrounding air and causes water vapor to condense
• Optionally, add a bit of warm water to speed up the effect

This gives you:

• A vivid example of a solid turning directly into gas
• A chance to compare dry ice behavior with regular ice, which melts first
• A real-world tie-in to how frozen CO₂ behaves on Mars, a topic covered in NASA education resources at nasa.gov

Safety note: Dry ice must be handled with insulated gloves or tongs, and containers must never be sealed because of pressure buildup.

Variation 5: Iodine sublimation (for older students)

For high school or early college labs, iodine crystals provide another example of sublimation. Gently heating iodine in a fume hood produces a striking purple vapor, which later deposits as shiny crystals on a cooler surface.

This is a nice contrast to dry ice because:

• It uses a different substance and color
• It shows both sublimation and deposition (gas back to solid)
• It reinforces that phase change behavior depends on the substance and conditions

Because iodine vapors are irritating, this one should be done with proper ventilation and protective equipment, as recommended in standard lab safety guidelines from organizations like the American Chemical Society.

Core example of supercooling: instant ice on command

Supercooling is one of the best examples of phase change experiments to grab students’ attention. You can buy bottled distilled water, chill it in a freezer until it’s just below 32 °F (0 °C) but still liquid, then trigger freezing on demand.

Basic procedure:

• Place unopened bottles of distilled water in a freezer for about 2–3 hours. You may need to calibrate the timing with a test bottle.
• Carefully remove a bottle without shaking it.
• Strike the bottle gently on a hard surface or pour the water over a piece of ice.

Students watch the liquid suddenly crystallize into ice in seconds. It’s a powerful visual example of how a phase change can be delayed until a disturbance or nucleation site appears.

You can tie this to:

• Real examples like supercooled water droplets in high-altitude clouds
• Weather phenomena such as freezing rain
• The need for nucleation sites (dust, impurities, scratches) for crystals to form

Meteorology resources from agencies like the National Weather Service at weather.gov cover supercooled droplets and freezing rain in the context of winter storms.

Variation 6: Cooling and heating curves with digital sensors

Many classrooms now have access to digital temperature probes and low-cost data loggers. That opens up a modern 2024–2025 twist on all the examples of phase change experiments: 3 practical examples described above: turning them into clean, shareable data sets.

You can:

• Record high-resolution temperature data for melting ice, boiling water, and supercooled water
• Plot cooling and heating curves in real time on a laptop or tablet
• Share the data with students online for further analysis and lab reports

This data-driven approach fits well with current STEM education trends that emphasize coding, data literacy, and reproducible experiments. It also lets students compare their curves to reference data from sources like NIST (nist.gov) or university physics labs.

Pulling it together: using multiple examples of phase change experiments in one unit

By now, we’ve gone far beyond a single example of a phase change experiment. Between melting and freezing (ice–water), boiling and condensation (water–steam), sublimation (dry ice, iodine), and supercooling (instant ice), you have at least six to eight concrete setups you can mix and match:

• Ice melting/freezing with and without salt
• Calorimetry to estimate latent heat of fusion
• Water heating to boiling with a visible plateau
• Condensation on a chilled surface as a micro water cycle
• Dry ice sublimation as a dramatic solid-to-gas transition
• Iodine sublimation and deposition for advanced students
• Supercooled distilled water that freezes on command
• Digital sensor–based heating and cooling curves across all of the above

Used together, these become some of the best examples of phase change experiments for building intuition about energy, temperature, and molecular motion. They also connect directly to real examples students recognize: road salt in winter, cooking at high altitude, fog and clouds, antifreeze, and freezing rain.

To keep things grounded and safe, it’s worth pairing these labs with up-to-date safety and scientific references. For general lab and classroom safety practices, the U.S. National Institutes of Health provides guidance at nih.gov, and many universities host detailed lab safety manuals on their .edu domains. For thermodynamic data and constants, NIST remains a gold standard.

When you plan your next thermodynamics unit, think of these examples of phase change experiments: 3 practical examples not as isolated “cool demos,” but as a coherent sequence:

• Start with simple ice and boiling water
• Layer on variations with salt, altitude, and condensation
• Finish with sublimation and supercooling as the capstone

Students walk away with more than a memory of foggy dry ice or instant ice bottles. They leave with a mental model of how matter changes state, how energy flows, and how those invisible processes shape the very visible world around them.

FAQ: Common questions about examples of phase change experiments

Q1. What are some easy classroom examples of phase change experiments?
Some of the easiest setups use water and ice: melting ice in a beaker while tracking temperature, boiling water on a hot plate to show the boiling plateau, and collecting condensation on a cold spoon held over steam. Dry ice sublimation and supercooling bottled distilled water are slightly more advanced but still manageable with basic equipment and good safety practices.

Q2. Which example of a phase change experiment is best for introducing latent heat?
Melting ice at 32 °F (0 °C) while recording temperature is arguably the best starting point. Students clearly see that energy is being added even though the temperature doesn’t change during the phase transition. For more advanced classes, a calorimetry experiment that estimates the latent heat of fusion of ice provides a strong quantitative follow-up.

Q3. Are there real examples of phase changes in everyday life that match these experiments?
Yes. Road salt lowering the freezing point of ice, water boiling at different temperatures at high altitudes, fog and clouds forming from condensation, frost forming by deposition on cold surfaces, and freezing rain from supercooled droplets are all real examples of the same processes you model in the lab.

Q4. How can I connect these examples of phase change experiments to current science topics?
You can link them to climate and weather (cloud formation, precipitation types), planetary science (dry ice on Mars), and engineering (refrigeration cycles, heat pumps, and antifreeze in engines). Using current data from agencies like NOAA and NASA helps students see that phase changes are central to how scientists model climate, design technology, and forecast weather.

Q5. What safety issues should I consider when running these experiments?
Standard lab safety applies: eye protection, careful handling of hot plates and boiling water, and clear rules about not touching equipment without permission. Dry ice and iodine need extra care—insulated gloves for dry ice, proper ventilation or a fume hood for iodine. Many school and university lab safety manuals available on .edu and .gov sites outline best practices for these materials.