Heat Retention Of Liquids

1. Heat Retention Of Liquids Jossette Quezada

2. Research My project for this year’s STEM Fair is on the heat retention of different liquids. Heat retention refers to the amount of heat an object, material, or liquid can hold overtime. Heat is a form of energy associated with the movement of atoms or molecules and is capable of being transmitted through solid and liquid. I’m testing different liquids. Acetone, acetic acid, iodine, milk, and olive oil which all have different heat capacities. Heat capacity is the amount of heat that is required to raise the temperature of an object or liquid. The basic unit used to measure heat is the joule. Since one joule represents a very small amount of energy it is common to measure it in Kilojoules (KJ) (1000 joules). Specific heat is the amount of heat that is required to change the temperature of one kilogram of a substance by one degree Celsius. Specific heat may be measured in KJ/Kg.K. Water has a very high heat capacity. It takes 4.2 joules of energy to raise 1 gram of water by one degree Celsius. Heat Capacities : • Vinegar – 2.043 KJ/Kg.K • Iodine – 2.15 KJ/Kg.K • Milk – 3.93 KJ/Kg.K • Olive Oil – 1.97 KJ/Kg.K

3. Variables and Controls • The independent variable in my experiment is the different liquids I am testing. • The dependent variable in my experiment is how long the liquids can retain heat. • The controls in my experiment are the starting temperature of the liquids and the amount of the liquid I am testing.

4. Hypothesis My hypothesis is that the liquid that gets heated the fastest will retain the heat the shortest amount of time. I think that if a liquid heats faster it cools faster.

5. Materials • Beaker • Timer • Hot Plate • Thermometer (C ) • Milk (100 mL) • Iodine (100 mL) • Olive Oil (100 mL) • Vinegar (100 mL) • Paper/Notebook • Pen/Pencil

6. Procedures • Gather all materials needed. • Turn on hot plate up to where it’s almost at it’s highest temperature. • Pour 100 mL of milk into the beaker. Place the beaker on the hot plate. Put thermometer in the milk and watch its temperature until it’s at 80 degrees Celsius. • When milk reaches 80 degrees turn the timer on. Take it’s temperature every minute for 15 minutes and record it on a notebook or piece of paper. • After you’ve concluded your results with the milk, clean the thermometer and clean out the beaker. • Pour 100 mL of iodine into the beaker. Place the beaker on the hot plate. Put thermometer in the iodine and watch its temperature until it’s at 80 degrees Celsius. • When iodine reaches 80 degrees turn the timer on. Take it’s temperature every minute for 15 minutes and record it on a notebook or piece of paper. • After you’ve concluded your results with the iodine, clean the thermometer and clean out the beaker.

7. Procedures (continued) • Pour 100 mL of olive oil into the beaker. Place the beaker on the hot plate. Put thermometer in the olive oil and watch its temperature until it’s at 80 degrees Celsius. • When olive oil reaches 80 degrees turn the timer on. Take it’s temperature every minute for 15 minutes and record it on a notebook or piece of paper. • After you’ve concluded your results with the olive oil, clean the thermometer and clean out the beaker. • Pour 100 mL of vinegar into the beaker. Place the beaker on the hot plate. Put thermometer in the vinegar and watch its temperature until it’s at 80 degrees Celsius. • When vinegar reaches 80 degrees turn the timer on. Take it’s temperature every minute for 15 minutes and record it on a notebook or piece of paper. • Gather and compare all your data and conclude your experiment.

8. Data Temperature (C) Time (minutes)

9. Results/Observations An observation that I saw in my experiment was that almost all of the liquids ended in the same temperature after 15 minutes. They all had a similar pattern. I would say the milk started cooling of pretty quickly and after about 7 minutes it started cooling slower. The iodine had an odd pattern in the beginning but later it started having a more constant rate in cooling. The vinegar and the olive oil took a while to heat up. The vinegar’s temperature went down at a constant rate and I would say it cooled the fastest. The olive oil was the liquid who was able to retain the heat the longest; it ended at 52 degrees after 15 minutes while the others ended at 50 and 49 degrees.

10. Conclusion My prediction that the liquid that heated the fastest will retain the heat the shortest time was incorrect. The vinegar was one of the liquids that took the longest to heat and it was the one who retained the heat the shortest time. The olive oil was the liquid to retain heat the longest and it took a long time to heat too. It’s confusing because the liquids that retained heat the shortest and the longest time were the ones that took the longest to get heated. What I can tell from my results is that the time it takes for a liquid to heat up does not affect how long it can retain the heat.