WHAT PHASE IS IT?

Task: Determine the phase of a substance you make in the lab & represent various parts of the activity using particle drawings.

Directions for making a substance

1) Use a graduated cylinder to measure 100 mL of water.

2) Pour the water into a 250 mL beaker.

3) Place the beaker of water on the hot plate & turn the hot plate to 3.

4) Place a weigh boat on the balance & record its mass on your lab sheet.

5) Before adding anything to the weigh boat, determine what the mass on

the balance will be after adding 4.0g of sodium borate to the weigh boat & RECORD this value on your lab sheet.

6) Measure out sodium borateinto theweigh boat until it reaches the

correct mass as recorded on your lab sheet.

7) While stirring with a stirring rod, add the sodium borate to it to the

beaker of warming water.

8) Mix the sodium borate solution with a stirring rod until all the borax

dissolves. The solution will look clear.

9) While waiting on the sodium borate to go into solution (get clear), obtain

a clear plastic cup and place it on the balance. Record its mass on your lab sheet.

10) Before adding anything to the weigh boat, determine what the mass on

the balance will read after adding 60g of PVA to the plastic cup RECORD this value on your lab sheet.

11) Using a popsicle stick to assist in pouring, measure out the PVA into the

cup until it reaches the correct mass as recorded on your lab sheet.

12) Once your sodium borate solution is clear (no white floaties), use a

graduated cylinder to measure 5 mL of the solution.

13) While slowly & constantly stirring with thepopsicle stick, pour the 5 mL

of sodium borate solution into the cup of glue.

14) Stir until you have a smooth consistency.

15) Take out the substance & roll it into a ball.

16) Do the following:

a) Pull the substance slowly & record observations on your lab sheet.

b) Pull the substance fast & record observations on your lab sheet.

TURN PAGE OVER TO CONTINUE

c) Make a 5 cm “log” out of the substance. Hold one end between your thumb and finger & let it “hang” above the lab table. Record observations on your lab sheet.

d) Roll it into a ball & place it back in the plastic cup.

e) Except for the cup with the substance. CLEAN UP your work place.

  • Sodium borate solution may go down the drain with the water running.
  • Rinse all glassware 6 times with tap water.
  • Follow this with 2 rinses with distilled water.
  • Dry glassware & put it away.
  • MAKE SURE YOUR HANDS HAVE NO SUBSTANCE ON THEM BEFORE YOU WASH THEM.

f) Look at the substance in the cup. Record observations on your lab sheet.

g) Record 2 more observations about your substance in the data table.

What Phase is it?

Task: Determine the phase of a substance you make in the lab & represent various parts of the activity using particle drawings.

Record of masses

Object / Mass (g)
Weigh boat
Weigh boat + sodium borate
Plastic cup
Plastic cup + PVA

Qualitative Observations Data Table

Action / Observations
Pull apart slowly
Pull apart quickly
Hang above table
Ball in cup at end
Other property
Another property

Data Analysis & Conclusions

1a) Compare your observations with another group. Record differences below.

b) What could explain the differences?

2a) Based on your observations determine whether the phase/state of matter of the substance.

b) Justify your decision with several observations (that is give reasons to back up your decision.).

3) Is this a mixture of 2 things (like chocolate milk) or did you make an entirely new substance? Justify your decision.

Particulate representations:

Sodium borate

Sodium borate solution

Substance