1. Evaporation vs. Boiling

2. Evaporation Liquid changing into gas.
Seems similar to boiling but there are differences.

3. Above the boiling point the substance is a gas.
Above the melting point the substance is a liquid.
Below the boiling point the substance is a liquid.
Below the melting point the substance is a solid.

4. Evaporation VS Boiling
Evaporation occurs on the surface of liquid and it is a vaporization of liquid. It is a state of transition from liquid to gaseous state. The process occurs slowly and cannot be seen as well. It occurs when there is exposure of water to air and water molecules change into vapor and these vapors rise up and form clouds.
Boiling occurs on the entire mass of liquid and it is the vaporization of liquid. It occurs rapidly. Boiling occurs when the temperature of the liquid is greater than the boiling point of the substance.

5. Differences Boiling Evaporation Occurs at fixed temperature
Occurs at any temperature
Quick process
Slow process
Takes place within liquid
Takes place only on surface
Bubbles are formed
No bubbles are seen
Temperature remains constant
Temperature may change
Heat supply by energy source
Heat supplied by surroundings

6. Factors Affecting rate of Evaporation
Temperature
Temperature of liquid and surroundings.
Surface Area
Presence of wind

7. Planning a Practical!
Next week you will be carrying out a practical. Before completing any practical you must first prepare the first part of the lab report…

8. Make a prediction! Write the title
“Investigating the Heating Curve of Water” in your book…this is the beginning of your first lab report!
Make a sub-heading “Prediction”
Under this you need to make your own prediction – what do you think will happen in the experiment? How do you think the temperature will change as time goes on?

9. Equipment list Make a new sub-heading “Equipment list”
Make a list using bullet-points of the equipment we will use:
Ice/Water Mixture
Hot Plate
Thermometer
Stopwatch
250 mL beaker
This is what we will measure the temperature of.
To heat the water.
To measure the temperature.
To keep the intervals between measurements the same.
To hold the water.

10. Labelled diagram Make a sub-heading “Labelled Diagram”
Draw a labelled diagram of how the experiment will be set up. Use pencil!!!

11. Procedure Make a sub-heading “Procedure”
Measure the initial temperature of the ice-water in your beaker and start the timer.
Measure the temperature after one minute.
Repeat step 2 every minute until the water has boiled away.
Combine results with one other group and calculate averages.
Plot a heating curve on graph paper.

12. Results Table – Make a sub-heading!! 
Time (min)
Temp. Test 1 (°C)
Temp. Test 2 (°C)
Average Temperature (°C) 1 2 3 4 5
Leave room to continue your time down to at least 30 minutes….don‘t close of the bottom of your table as it may take longer!