Comparing Rates of Evaporation
Several factors determine how fast a sample of liquid will evaporate. The volume of the sample is a key factor. A drop of water takes less time to evaporate than a liter of water. The amount of energy supplied to the sample is another factor. In this lab, you will investigate how the type of liquid and temperature affect the rate of evaporation.
Problem: How do intermolecular forces affect the evaporation rates of liquids?
Pre-Lab: Read the ENTIRE LAB first then answer the following questions
1. What is evaporation?
2. Describe what happens at the molecular level during
3. List the three intermolecular forces- Rank them in
4. Provide a list of materials needed to perform this lab.
5. Predict which liquids will evaporate quickly and which will take longer. Give reasons for your predictions.
6. To calculate the evaporation rate, you would divide the evaporation time by the quantity of liquid used. Explain why it is possible to use just the evaporation times from this lab as evaporation rates.
1. Place tape to secure your wax paper to lab table.
2. PRACTICE: to ensure that you have drops of equal amounts, use the DH2O dropper to make consistently similar drops. When you feel that you mastered this, proceed to the next step. PRACTICE: Make sure you know how to use a stop watch. ALL times will be converted into seconds!! 3. If you need new wax paper, then repeat step 1.
4. With the one sharpie pen at your table, create a space for your drops- label them A-F. 5. With a steady- mastered hand, place ONE drop of liquid in its predetermined space. Start timing!! 6. While you are waiting for it to completely evaporate, in the data table provided, Make two drawings of your drop. Top view- as you view it from above and side view at eye level. 7. If the drop takes longer than 5 minutes (>300 seconds),...