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

6. 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 questions…what 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?

9. Scoring • Your grade for the write-up will be determined by the following factors • Organization and clarity • Logical flow to analysis/error analysis • Don’t 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