Lab Write-up Expectations HeadingStart by writing down the title at the top of the lab report rubric. ex. How does temperature affect the solubility of a substance? Include the date, your name, and your portfolio number. 1. Prelab ActivitiesThe following activities should be completed the night before the scheduled lab activity: - hypothesis - variables and controls - lab safety - observation table - print off a copy of the lab instructions and lab report rubric from Classnet 2. Purpose/Problem Write down the purpose with a "The purpose was to ...." statement. ex. The purpose was to learn how temperature affected the rate of diffusion. 3. HypothesisUse a hypothesis with an "If ..., then ..." construction. ex. If temperature increases, then the rate of diffusion will also increase. 4. Variable & ControlsWrite down the manipulated, responding, and controlled variables. Manipulated - the factor that is changedex. Temperature Responding - the factor that changes as a resultex. Diffusion distance Controlled - the factors that must be kept the sameex. Solute and solvent 5. MaterialsList the materials and equipment used in the experiment in point form. Use a separate list for chemicals and equipment. 6. Lab SafetyWrite down safety concerns to demonstrate awareness of any potential hazards. These include personal safety, environmental safety and disposal of chemicals. ex. Copper chloride needs to be disposed of in the appropriate waste container. 7. ProcedureWrite the procedure in numbered steps. Use the past tense and no personal pronouns. ex. #1. 10 mL of tap water was measured and poured into a test tube. 8. ObservationsWritten observations should be brief, accurate, and concise. The observation - writtennumber should be the same as the step of the procedure that produced it. ex. #4. The blue crystal dissolved in a circular pattern that continued to grow. 9. ObservationsData should be organized in a clearly labeled table that includes all of the appropriate - tableS.I. units. 10. ObservationsDiagrams should be completed with a sharp pencil on blank paper. Make the diagram - diagramlarge and to the left side of the paper. Use a ruler to clearly line up the labels to the right of the diagram. Avoid crossing your arrow lines. 11. Lab PerformanceRead the procedure carefully, and safely follow the instructions. Make every effort to reduce experimental error and produce accurate and precise results. Clean up your lab station. Safely dispose of waste, and return equipment. 12. AnalysisGraphs should be completed manually on grid paper or electronically on the computer. - graphingGraphs should fill the page with an appropriate choice of scale so that relationships between variables are revealed. 13. AnalysisProblem solving should be presented in the proper format. Calculations should be - calculationsprovided with the correct S.I. units. 14. ApplicationNumbered questions should be answered thoroughly and accurately in complete - questionssentences. Excellent lab reports will demonstrate evidence of outside research. 15. Sources of ErrorReview the lab procedure, and list possible sources of error that may have compromised the quality of the data collected. Consider how the sources of errors may be eliminated or reduced to improve the validity of the results. This section does not include errors that you made. 16. ConclusionWrite down a summary statement of your conclusions. Refer back to the purpose/hypothesis of the experiment.