Effect of surface area on evaporation rate

Effect of surface area on evaporation rate

Pencil and paper
Overview
Using this Resource
Connecting to the Curriculum
Marking Student Responses
Further Resources
This task is about the relationship between surface area and evaporation.
Task: To show that surface area influences the rate of evaporation

  • Trace around the top of these three containers; petri dish, measuring cylinder, 100 mL beaker, on a piece of graph paper.
  • Calculate the surface area of each container by counting the squares on the graph paper.
  • Pour 25 mL of water into each container.
  • Leave the 3 containers in the same place for 3 days.
  • Measure the volume of water left.
a)
Complete the results chart. 
 
  Surface area Original volume of H2O (mL) Final volume of H2O (mL) Water loss (mL)
Petri dish        
Beaker        
Measuring cylinder        
 
b)
 
i)
 
Which container lost the most water over the 3 days? ____________________
  ii)
Why did this container lose more water?
 
 
 
 
  iii)
Explain what happens when water evaporates.
 
 
 
 
 
c)
How could the rate of water loss in this experiment be increased? 
 
 
 
 
 
 
 
Task administration: 
This task can be completed with pencil and paper and other equipment.
 
Equipment
Petri dish; measuring cylinder; 100 mL beaker; graph paper; water.
Level:
4
Curriculum info: 
Science, Investigating in science, Material World
Keywords: 
changes, evaporation, surface area, fair testing, practical, investigation
Description of task: 
This practical task has students investigate the surface area of three objects and whether this influences the rate of evaporation. Students fill in a table, and calculate the water loss and answer questions to show their understanding.
Curriculum Links: 
Science capabilities
The capabilities focus is brought about by the conversations you have and the questions you ask.
 
Capability: Gather and interpret data
This resource provides opportunities to discuss methodology and patterns in data.
 

 
Science capabilities: 
Gather and interpret data
Answers/responses: 
a)   Table completed accurately.
b)

i)
ii)
iii)

Petri dish.
Because it had the greatest surface area.
Water changes from a liquid to a gas.
c)   Increasing the air temperature/increasing the air movement.

NOTE: A possible extension would be to ask students if this was a fair investigation, e.g., has the height difference between the containers been a part factor in contributing to different rates of evaporation.