Lab Help

• How should I organize my lab book?
• I need help with
  • Writing a hypothesis
  • Recording raw data
  • Showing example calculations
  • Calculating percent error
  • Writing a conclusion
• What to include for Lab Notebook Entries
  • Experiment Reports (Used for conducting a formal experiment that either you designed, or I designed)
  • Observation Report (Used to record your observations and thoughts during exploration activities and demonstrations)
  • Planning Report (Used for planning experiments that you have designed)
  • Grading Policy
  • Rubric
• What to include for Formal lab write-up
  • Guidelines
• Lab Safety Links
  • Lab Safety Info
    
  • MSDS Database
  • Chem Info Net
• Lab Techniques Links
  • Distillation

The lab notebook should be a spiral bound or composition style notebook. I recommend getting a notebook with grid paper which makes it easier to make graphs and tables. I also suggest against the wireless kind with easy tear out pages - the covers and pages quickly come apart and most likely won't withstand the beating they will take coming to class everyday. The lab book should be organized as follows:

• Table of Contents
  • Label the top of the first two leaves as Table of Contents
  • Make columns for
    • Experiment Name
    • Partner
    • Page Number
    • Clean-up Sticker
• Page Headings
  • Number each page of your lab notebook beginning with the table of contents
  • As you use a page, sign (initials OK) and date it in the upper right hand corner
• Handouts
  • Tape periodic table to inside back cover
  • Tape equation sheet to inside front cover
  • Tape example handouts on back pages
• Other
  • Write in non-erasable ink.
  • Never scribble out words, figures, or numbers. Draw a single line through them instead.
  • Avoid blank pages
  • Number your pages when you first get the book. You should not rip pages out of your lab notebook.
  • Write on the right hand side of the page. Use the left side for notes to yourself but not lab procedures, data, etc.

The experiment report is used when you are testing a hypothesis. The hypothesis may have been made up by you or it may have been given to you by me. These reports are more of the typical lab report you may be used to from other classes. Experiment reports should include the following sections in this order. Underline or highlight in some way the section titles.

• Title and formatting (5 pts)
  • Make it meaningful
    • eg: "Lab experiment" is not an acceptable title but
    • "Observations on Melting Ice" is.
  • The recommended format is followed: Title, Question, Hypothesis, Procedure, Data, Results and Analysis, and Conclusion sections are clearly labeled.
  • Name, date and page number appear on each page
• Problem/Question (2 pts)
  • The question or problem statement is present and gives reader idea of what will be done in the lab.
• Hypothesis (5 pts)
  • Make a prediction
  • Explain why this is your prediction
  • Help
• Procedure (5 pts)
  • The procedure is descirbed in enough detail that another scientist may repeat it
  • Reference is made to detailed instructions with any modifications made
  • Alterantively a brief outline of procedure with diagrams may e made
  • All materials are indicated
  • The method is realistic and allows for control of the variables
• Data / Observations (10 pts)
  • Record ALL measurements (Raw Data Help).
  • Organize data in tables and give the tables titles
  • Record constants such as temperature, pressure, and concentration
  • All numbers need units
  • Use Significant Figures (and possibly uncertainties)
  • Record errors that occur or difficulties that arise (alternatively, record this in procedures section)
  • Graphs should have titles, legends, and labels on axes with units
• Results and Analysis (10 pts)
  • A narrative pagaragraph should be written to desribe your data analysis.
  • Analyzed data should be represented in tables or graphs and titled and labled appropriately.
  • Sample calculations ( Help )
  • Answers to questions I give you
• Conclusion (10 pts)
  • Summarize what was done - restate the purpose/question.
  • State whether or not the hypothesis was right or wrong
  • Draw a conclusion as to what you learned
  • Use data to defend conclusion
  • Summarize errors that occurred - reasons why your conclusion might not be accurate. (Human error, time constraints, and group problems are not things you should list. Be specific.)
  • Compare to a known value if possible and calculate percent error
  • Suggest future questions that should be explored
  • Conclusion Template

Please e-mail (wisemanm@fccps.k12.va.us) me with questions you have about lab entries that are not answered here.

Rubric

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Use the Observation Report to organize your observations during a "hands-on" activity that isn't quite a lab. Also, use them to record demonstrations.

It includes:

• Question
• Prediction
• Observations table (what was done - what happened)
• Summary

Example

Think of the Planning Report as a "Pre-Lab." Use it to organize yourself when designing an experiment or preparing for one.

Some of things it may include (this is a bit more free-form than the observation and experiment reports):

• Question to be answered
• Possible hypothesis (at this point there can be more than one...)
• Experiment diagram
• Suggested materials
• Outline of procedures
• Flow chart of lab steps
• Pre-lab questions

Lab notebooks must be separate from the notebooks you use to take notes since I will be collecting them and you may need your notes while I have your lab notebook

When I collect lab notebooks, I will only collect 1 from each group. You will decide as a group whose lab notebook will be turned in. However, everyone must have a complete lab write-up in their notebook the day it is due. Pages will be stamped to ensure this. At the end of the quarter, I will collect everyone's lab book and verify that you have completed all lab write-ups on time. If any are missing or missing date stamps, those points will be subtracted from your grade.

Rubric

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The purpose of the lab report is to have you (the student) use a complete range of communication skills in presenting experimental work and its relation to underlying theory. the report should be type written using a third person narrative style of writing. Your full write up lab reports should include the following parts:

Title

• Make it meaningful

Abstract

• The purpose of the abstract is to give a short summary of what was done and what conclusions were reached.
• It should not be a repetition of the title
• Often, only abstracts are published and scientists read the abstract to know if the results are applicalbe to whatever they are researching.
• Think of the abstract like it's the blurb on the back of a book that gives away the ending.

Introduction

• The purose of the introduction is to introduce the reader to your experiment - why are you doing this and in what context?
• The problem should be stated.
• A reference to textual material should be made to give context to the problem.
• The question to be investigated should be precisely stated.
• A hypothesis should be given containg both a prediction and a reason
• Variables should be identified including manipulated (independent), measured (dependent).

Procedure

• Same as experiment report.

Data

• A copy of the raw data should be presented in table form (even observations can be in tables).
• Tables should contain a title (sentence format), headings, units (and possibly uncertainties).
• The data should come directly from your lab notebook.

Results and Analysis

• Same as experiment report.

Conclusion

• Same as experiment report.

When writing a hypothesis you must make a prediction and justify your prediction using scientific terms

Example:

• Question: Will this white crystalline, brittle substance dissolve in water?
• Hypothesis: I predict that the substance will dissolve in water because its physical properties (brittleness, crystalline form) indicate that it is an ionic compound and and ionic compounds are known to dissolve in water.

Raw data is any value that is directly measured. Here is an example of the difference between raw data and calculated data

Let's say you want to calculate the volume of a peanut by displacement...

• Fill a graduated cylinder with water
• (RAW DATA) Record the initial level of the water
• Put the peanut in the graduated cylinder
• (RAW DATA) Record the new level of the water
• (ANALYZED DATA) Subtract the initial level from the final level to get the volume of the peanut.

What should the data table look like?

Why is it important to write down raw data? Because if you make a mistake in your calculations and all you wrote down was the analyzed data - it is impoossible to go back later and correct your mistake.

The purpose of showing your calculations is to make it clear how a particular value was calculated. This is most important when the calculation you do is unique or when there are other methods possible.

It is not necessary to write out every single calcuation you do for an experiment. It is only necessary to show examples of the type of calculations you did.

Let's say you are calculating the density of a type of plastic and you have measured three different size pieces and have the following data:

Trial	Mass	Volume	Density
1	5.0 g	1.0 L	5.0 g/L
2	10.0 g	2.0 L	5.0 g/L
3	15.0 g	3.0	5.0 g/L
Average			5.0 g/L

Under the calculations heading you should show a sample density calculation and a sample average calculation. Even though you did three density calculations, just show one. Your example should include data from your experiment - not just random numbers.

Calculations
Density = mass/volume = 5.0g/1.0L = 5 g/L
Average = (5.0 g/L + 5.0 g/L + 5.0 g/L)/3 = 5.0 g/L

• Calculated density (measured by you in lab): 5.0 g/L
• Actual density (according to a book): 5.2 g/L

1. Find difference = 5.0 - 5.2 = 0.2
2. Calculate % error = 0.2/5.2 = 4%

• Conclusion Template
  • In this lab we attempted to (answer the question / figure out why / measure / verify)      (question you tried to answer)      by      (describe method you chose)     . Our results (were /showed / gave)      (state conclusion)      which (ageed / somewhat agreed / did not agree) with our hypothesis. This means that      (what you learned about chemistry concepts from this lab)     . The problems we encounterd in this lab were      (sources of error)     . We (do / do not) believe these errors significantly affected our results (and / but) we could improve our results by      (list ways you could have designed/performed the lab so that these problems did not occur)     . Further questions we could investigate here are      (other possible answers to the lab question)     .
• For quantitative results (actual numbers) include your percent error when discussiong whether or not your hypothesis was right.