Project I:  Density

For project 1, we will follow the lab on page 93 of the Cooperative Chemistry Laboratory Manual, 4th edition.  We will deviate from the lab manual slightly.  You will be required to devise and carry out one experiment that will allow you to measure the density of a solid material and one experiment that will allow you to measure the density of a liquid material.  You will be graded on the method you devise so be sure to read the background material so that you can use the best methods for making measurements.  We will use two different methods for analyzing the data you collect. 

We will begin the lab with writing an Experimental Plan.  Each group of 4 must write an experimental plan before beginning the lab.  The experimental plan should discuss the problem you are investigating and how your team plans on solving the problem.  Some possible questions to keep in mind while writing your experimental plan are: What are your goals?  What experiments do you plan to run to reach your goals? What physicals properties must you measure?  What materials and lab equipment will you need?  How will you analyze your raw data?  Your experimental plan must be turned into your lab instructor the week before starting experimental work in lab.  Each member of your group is required to keep a scientific notebook.  Your notebook is where you will record your day-to-day activities in the lab.  You should describe experiments as you do them and note observations as you make them.  You should also record and analyze your data in your notebook.  We will conclude the experiment with a lab report that contains an introduction and a results and discussion section.

Requirements for collecting data:

• Work in groups of 2 to collect data, but collaborate with another group of two and share your data.
• Each group of two must determine the density of one solid and one liquid.  You then must share your results with another group of two who worked with a different solid and liquid than you.

Requirements for analyzing your data for the density of the solids:

• Create a table showing the data you collected.  One table should show the data for both solids.
• After generating your table, calculate the density for each trial and be sure to report these values in your table.
• Calculate the mean density and the standard deviation for each solid.  (What is the best format for reporting this data in your results section of your lab report?)

Requirements for analyzing your data for the density of the liquids:

• Create a table showing the data you collected.  One table should show the data for both liquids.
• For each liquid, the density will be determined graphically.  Thus, prepare a graph of mass of water vs. volume using an Excel spreadsheet.  We will use the convention y vs. x, thus mass of water on the y-axis.  Be sure to follow guidelines in the lab manual and the Graphing with Excel web tutorial for proper graphing requirements.
• A plot of mass vs. volume will produce a straight line with the slope of the line equal to the density.  Be sure to add a trendline and include the equation of the line on your graph.

Requirements for writing your lab report:

• The lab report is an individual project.  Although you collected data in a group, the lab report is an individual project.  Thus each member of the group must generate their own tables and graphs and write their own lab report.
• All results must be reported in tabular format.  (Use your textbook as a reference to see the proper format for a scientific table.)
• Your lab report will consist of a results and discussion section with data tables and graph.  In the results and discussion section, you must include an example of how you calculated the density and show the calculation for the standard deviation.
• All lab reports must be typed including all tables.

Grading Project I:

·         Experimental Plan (10 pts)

·         Notebook (10 pts) 

o       Bound pages, not loose leaf or spiral, etc.

o       Descriptive Table of Contents

o       Numbered pages

o       Include date data was collected

o       Raw data recorded

o       Procedures and observations recorded

o       Written in ink

o       Mistakes crossed out appropriately

·         Lab Report (30 pts)

o       Results and Discussion

*  Is data reported in tables?

*  Is data reported in the proper scientific format (correct units, significant figures?)

*  Analysis of data included in report?  Mean?  Standard deviation? Graphs?

·         Peer Evaluation (10 pts)

·         Quiz (10 pts)

Background Reading:

Cooperative Chemistry Laboratory Manual

·         Safety Rules, Laboratory Etiquette (12-14)

·         NFPA Hazard Codes, Waste, MSDS’s (15-16)

·         Recording and Reporting Results (17-19)

·         Writing Lab Reports (19-23) (This semester we will focus our attention on the results and discussion only)

·         Reporting Numerical Results, Significant Figures, Graphs (35-40)

·         Measuring Devices (47-49)

·         Reading a Meniscus (67-68)

Chemistry & Chemical Reactivity

·         Section 1.1 Chemistry and Its Methods

·         Section 1.5 Physical Properties; Density

·         Units of Measurement (25-30)

·         Making Measurements (30-32)

·         Mathematics of Chemistry (32-37)

Chemical Principles, The Quest for Insight

·         Section A.1, Physical Properties (pp F6-F10)