9/20 Mothball Phase Change Lab Read through the powerpoint and then fill out the survey on the blog

We’ll be observing the physical property of the mothball changing states of matter (phase changes) You’ll have people observing what the mothball looks like as it changes Observe the temp as it changes Checking the time Recording data

2. Decide Duties on Friday scribe/writer/timer: records main points of lab Has good handwriting data recorder: records data on data table data looker: reading the temperature hands/eyes: observe phase changes & moves apparatus *thermometer 3. In lab notebook  you’ll write down everyone’s name and their duty

4. All discuss & complete pre-lab in class 4. All discuss & complete pre-lab in class. We want to see how a mothball (it looks like a gobbstopper but don’t eat it) can change from being a solid  liquid  gas then back to a liquid  solid

This is what you’ll be using Mothball Test tube Thermometer (not for stirring) Ring stand Heat stand Beaker Water Stopwatch (on phone or one of mine) Alcohol burner goggles

Procedures (don’t write) Set up apparatus Read initial temp on thermometer Record temp and phase on data table 4. Observe Solid, Liquid,Gas 4. Start timer

Scribe: Will call out time/record every 30 sec Everyone repeats observes/records every 30 sec Keep heating until the mothball is boiling or temp is more than 130 C If the temperature (red line on thermometer) gets above PULL IT OUT OF THE TEST TUBE or else you will break it

When mothball is completely melted and temp reaches 130 C… Hands/Eyes – Move burner away from the test tube Blow out burner Move ring stand/test tube up Place beaker under test tube Lower test tube into the beaker

Keep recording data until mothball is completely frozen Keep recording data until mothball is completely frozen. Keep taking temperature **Don’t stir with the thermometer  it’ll break Record until temperature stays the same for 2 minutes

Data Table (on graph paper or notebook) 18 rows Time Temperature ( C) Observations (Solid, Liquid, Gas…) :30 1 min 1:30 2 2:30 3 3:30 4 4:40 5 5:30 6 6:30 7 7:30 8

All graph – line graph T E M P E R A T U R E C 140 130 120 110 100 90 80 70 60 50 40 30 20 10 1 1:30 2 2:30 3 3:30 4 4:30 5 5:30 6 6:30 7 7:30 8 Time

We’ll discuss, Scribe writes - Dependent/Responding Variable: ________ Independent/Manipulated Variable:_______

All write Conclusion: What did you observe? Further Questions/what would you change?: Now go fill out the survey on my blog saying you read through the powerpoint