Observations Result It is observed that maximum evaporastion occurs in the petridish with largest diameter is followed by the smaller and the smallest. Additionally, I recall that the rate of evaporation is affected by pressure. I would also like to thank my lab incharge Mr. Place both glasses next to each other on a counter out of the sunshine. After a few days in the warm sun, the liquid in your bowls will have evaporated.
One of the plates is placed directly in the pat of the wind from the fan and the other plate is placed away from the fan. Figure 1a shows how water and oil separate in the separatory funnel, while figure 1b shows the actual apparatus. Air current flowing over the surface of the liquid took away the molecules of the substance in vapour state there by preventing condensation. Observation What happens with each check of the liquid levels? Clean and dry all Petri dishes and mark them as A, B and C. As a result, liquids with strong intermolecular attractions evaporate more slowly than liquids with weak intermolecular attractions. The dependent variable is the rate of water evaporation. So all it depends on vapour pressure and force of attraction.
This is due to the reason that the molecules which undergo evaporation have high Kinetic energy therefore the kinetic energy of the molecules which are left behind is less. Clean and dry the three weight bottles and label the A, B, and C. However, this would be a good place to start your research. Step 5: Conclude the project from your observation. At a lower atmospheric pressure, less energy is needed by the water molecules to escape into the atmosphere. Why do different liquids have a different rate of evaporation? Next, set beakers in a stable environment. Observe the length of time that it takes for each sponge to dry completely.
In hydrology, evaporation and transpiration which involves evaporation within plant stomata are collectively termed evapotranspiration. Keep all the resources handy before starting the project. If such molecules happen to come near the surface in a sample of liquid all the molecules do not have same kinetic energy. Compare the prior and present observations. Analysis Discussion The energy buildup in the molecules causes them to evaporate. That is contingent upon density and temperature as well as the obvious--how much of a given liquid you have. The wind from the fan will reduce the air pressure around the first plate.
Higher temperatures also increase the rate of evaporation. Therefore temperature is kept constant the remaining liquid will have same distribution of the molecular kinetic energy and high molecular energy will kept one escaping from liquid into gaseous phase of the liquid is taken in an open vessel evaporation will continue until whole of the liquid evaporates. Intermolecular attractions affect the rate of evaporation of a liquid because strong intermolecular attractions hold the molecules in a liquid together more tightly. Then pour out that water and fill the cup with water from the soup bowl. This is due to the reason that the molecules which undergo evaporation have high kinetic energy therefore the kinetic energy of the molecules which are left behind is less. In hydrology, evaporation and transpiration which involves evaporation within plant stomata are collectively termed evapotranspiration.
Place the ruler in the bowls and note the depth. In this experiment, the time taken for a drop of propanone to evaporate is measured under a number of different conditions and compared. The thermal motion of a molecule must be sufficient to overcome the surface tension of the liquid in order for it to evaporate, that is, its kinetic energy must exceed the work function of cohesion at the surface. Let the Petri dishes remain exposed for 10 minute. Water from the oceans evaporates and forms clouds in the sky. If fresh air is moving over the substance all the time, then the concentration of the substance in the air is less likely to go up with time, thus encouraging faster evaporation.
Theory: For molecules of a liquid to evaporate, they must be located near the surface, be moving in the proper direction, and have sufficient kinetic energy to overcome liquid -phase intermolecular forces. Clean and dry all Petri dishes and identify them as A, B and C. The container with the largest surface area should have had the most evaporation. Let me know if you have any other questions or if any of these answers require clarification. If you are plotting a graph for your research data, the remaining liquid in ml would be your dependent variable and the no.
The results are recorded in the table below. . Hi, Ultra can you give me your email if you have one???? The constants or controlled variables are the containers the liquids are kept in, where they are kept, and the amount of liquid in each container. The other liquids could really be anything. Internal Assessment: Rate of Evaporation Ann George Mr. This question in particular sounds like it should be answered by the investigator. Factors Influencing Rate Of Evaporation :- Concentration of other substances in the air- The strength of the content is evaporating in the air.