Lab-Paper-Towel-Absorbency-and-Strength

					Lab-Paper Towel Absorbency and Strength
I. Purpose:
   To test the absorbency and strength of different paper towels. Secondarily, this lab emphasizes the
   importance of following instructions carefully.

II. Materials:      water                              3 different types of paper towels
                    eyedropper                         400 ml beaker
                    50 ml graduated cylinder           rubber band
                    pennies

III. Hypothesis (Predication or Educated Guess):
   If three paper towel types are tested (1. ____________________ paper towel brand, 2.
   ____________________ paper towel brand, and 3. ____________________ paper towel
   brand), then the ___________________ paper towel brand will hold the most drops of water
   before dripping, the ____________________ paper towel brand will absorb the most water, and
   the __________________ paper towel brand will be the strongest.

IV. Procedure:
   1. Put your name, date, and period at the top right of this sheet.
   2. In the space to the right of the word "Hypothesis" above, write a hypothesis that predicts the
          order of absorbency and strength of the paper towels (follow my example in class).
   DROP TEST
   1. Place towel A over the 400 ml beaker. Keep it tight with a rubber band.
   2. Fill the eyedropper with water.
   3. Place the bottom of the eyedropper directly over the paper towel at a height equal to the height
          of the 50 ml graduated cylinder, and drop one drop at a time keeping count.
   4. Stop as soon as you see water leaking into the beaker.
   5. Record the number of drops in the data table, and repeat steps 1-4 for three trials.
   6. Repeat steps 1-5 for all three types of paper towels.
   7. Rank the towels from the one that absorbed the most drops (#1), to the one that absorbed the
          least drops (#3).
   POUR TEST
   1. Place Towel A over the 400 ml beaker. Keep it tight with a rubber band(s).
   2. Measure 25 ml of water in a graduated cylinder.
   3. Pour the 25 ml of water onto the towel slowly. Let the water run through the towel.
   4. Remove the paper towel, pour the remaining water from the beaker into the DRY graduated
          cylinder and measure the volume of water.
   5. Record the ml of water in the data table, and repeat steps 1-4 for three trials.
   6. Repeat steps 1-5 for all three types of paper towels.
   7. Rank the towels from the one with the least ml's left in the beaker (#1), to the one with the most
          ml's left in the beaker (#3).
   WET STRENGTH TEST
   1. Place Towel A over the 400 ml beaker. Keep it tight with a rubber band(s).
   2. Measure 25 ml of water in a graduated cylinder.
   3. Pour the 25 ml of water onto the towel slowly. Let the water run through the paper towel.
   4. With the wet towel tightly over the beaker, drop the pennies (as flat as you can drop them), one
          at a time, from the height of the 50 ml graduated cylinder. CHECK for rips after each penny
          is dropped. Go up to 100 pennies. Once 100 pennies is reached, stop and record 100.
   5. Record the number of pennies it takes to rip the towel , and repeat steps 1-4 for three trials.
   6. Repeat steps 1-5 for all three types of paper towels.
   7. Rank the towels from the one that held the most pennies (#1), to the one that held the least
          pennies (#3).
V. Data and Observations:
1. Information on Paper Towel Types:
   Paper Towel:              Name:                                    Cost:       # of Sheets: Cost/Sheet:
         A:
         B:
         C:
2. Drop Test:
          Trial:                    Paper Towel A:              Paper Towel B:             Paper Towel C:
             1:
             2:
             3:
    Average # of Drops:
     Rank (1, 2, or 3):
3. Pour Test:
          Trial:                     Paper Towel A:              Paper Towel B:             Paper Towel C:
             1:
             2:
             3:
    Average ml Left in
         Beaker:
     Rank (1, 2, or 3):
4. Wet Strength Test:
          Trial:                    Paper Towel A:               Paper Towel B:            Paper Towel C:
             1:
             2:
             3:
    Average # of Pennies:
     Rank (1, 2, or 3):

VI. Conclusion:
On a separate sheet of paper, answer the following questions completely. Staple your answer sheet to
the back of this lab sheet.
1. In your hypothesis, on what basis did you predict the paper towel that would hold the most drops during the
    Drop Test?
2. In your hypothesis, on what basis did you predict the paper towel that would absorb water (i.e. have the least ml
    left in the beaker) during the Pour Test?
3. In your hypothesis, on what basis did you predict the paper towel that would hold the most pennies during the
    Strength Test?
4. Check your original hypothesis. Were your predictions correct for the Drop Test, Pour Test, and Strength
    Test?
5. Give some reasons why lab groups in the same classroom may have different results than your group observed.
6. Does it really matter if your results are different than your original hypothesis?
7. Why is a good idea to use the class average and not just the data from one group?
8. Overall, which paper towel is the best value? What evidence do you have to support your opinion?

				
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posted:11/30/2009
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