Alkane Viscosity Experiment

1
Alkane Viscosity Experiment
2
Viscosity of Alkanes Experiment

• First Experiment
• Measured viscosity using marble drop
• Timed from 80 mL to 30 mL
• Problems?
• Timing difficult (marble too fast)
• Marble may have variable weight
• Others?
• Further Experiments
• More reliable timing data
• Determine the effect of marble mass on data
  collection

3
Alkane Viscosity

• Further Experiments
• More reliable timing data
• Measure time over longer distance (100 mL?)
• Perform more trials to ensure consistency and
  discard outlying data
• Determine the effect of marble mass on data
  collection
• Perform trials of 1 oil using different marbles
  to ensure that data collection is unaffected
• Provides evidence to defend experimental setup
  when presenting findings

4
Alkane Viscosity

• Three additional experiments
• 1. Re-do previous experiment with 100 mL
  distance
• 2. Perform marble drop with 1 oil, using 5
  different marbles (mass each first) at 3 trials
  each
• 3. Determine density of each oil to establish
  a correlation (or lack thereof) between density
  and viscosity

5
Alkane Viscosity Report

• Data Tables (typed) of all collected data for all
  experiments
• 50 mL drop experiment, 9 oils x 3 trials each (
  avg. time for each 36 data points)
• 100 mL drop expt, 9 oils x 3 trials each ( avg.
  time for each 36 data points)
• Marble mass expt, 5 marbles x 3 trials each (1
  oil for total of 20 data points)
• Density, 6 oils (expressed as g/mL)

• Make sure that tables are clearly labeled and
• organized logically

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Alkane Viscosity Report

• Graphs
• 1. 50 mL drop graph average drop time for
  each oil
• 2. 100 mL drop graph avg. drop time for each
  oil
• 3. Superimpose both graphs with different colors
  for each line (double 50 mL data)
• 4. Marble mass graph average time for each
  marble
• 5. Density graph density for each oil
• 6. Graph density vs. 100 mL drop time

7
Analysis

• After creating tables and graphs, analyze
  available data
• Possible questions to consider
• Was the 100 mL drop data more reliable than the
  50 mL drop? How can you tell?
• Does the mass of the marble affect drop time? Is
  it significant enough to alter our experimental
  design?
• Is there a correlation between oil density and
  viscosity (i.e. drop time)?
• If density does not explain viscosity, then what
  other experiments could be done in the future?
• Consider other questionswhat does the data
  indicate? What does it NOT indicate?

8
Lab Report Write-Up

• Organized tables and graphs
• Analysis section
• Error Analysis
• What were problems with the experimental design?
• For what variables have we NOT accounted?
• In collecting your data, what errors may have
  occurred?
• How reliable is your data?

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Scoring

• Your grade for the write-up will be determined by
  the following factors
• Organization and clarity
• Logical flow to analysis/error analysis
• Dont answer each question individually
• The answers should all be presented together as
  part of your overall analysis
• Thorough consideration of questions in analysis
  and error analysis sections
• Consideration of other factors/questions