One of the important physical properties of a liquid is the temperature and the time it takes to freeze. These physical properties may change when other materials are dissolved in or mixed with liquids such as salt, sugar or tea.
Variety of Liquids
Create a homework science project by having students test a variety of liquids such as orange juice, tea, water and milk to see which liquid freezes faster. Have students write out a hypothesis of which liquid would freeze first and why. Hand out three to four cups per student to take home for the project. Instruct students to fill each cup halfway with a different liquid and place in the freezer. Then have students check to see if the liquids are frozen by inserting a toothpick in each cup every 25 minutes. Instruct students to record their observations, such as which one froze first, second and last and compare the result to their hypothesis. The results will be that water will freeze first since it doesn’t have other ingredients.
Water vs. Salt Water vs. Sugar Water
Create a science project to find out which will freeze first--tap water, sugar water or salt water. Write out a hypothesis of which liquid would freeze first and why. Fill three cups with a half-cup tap water each. Leave one cup as regular tap water, add one tablespoon of sugar to the second cup and add one tablespoon of salt to the last cup. Mix well to dissolve. Place all three cups in the freezer and check every 30 minutes to see which one will freeze first. Record your observations, such as which one froze first, second and last and compare the result to your hypothesis. The results will be the regular tap water will freeze first; the sugar will freeze second and the salt water last.
Hot Water vs. Cold Water
Create a hot versus cold water freeze project. Write out a hypothesis of which liquid would freeze first and why. Then take two cups and fills each one halfway using hot water for one and cold water for the other. Put them in the freezer and check them every 25 minutes to see which one will freeze first. Record your observations and compare the result to your hypothesis. The hot water will freeze first since it is less likely to contain gas bubbles.
Fresh Water vs. Salt Water
Create a science project to determine which will freeze faster, salt water or fresh water. Write out a hypothesis of which liquid would freeze first and why. Put a liter of cold water in a same size container. Add salt in one container and stir smoothly. Measure and record the temperature before placing them inside the freezer. Check and record the temperature every 30 minutes. Record your observations.The results will be that fresh water freezes faster than salt water.