LAB WRITEUP FORMAT – AP CHEMISTRY – KLAMM – 2015/2016
Throughout the year, we will perform many laboratory experiments. Most times, a lab report will follow as the result of the laboratory activity. The purpose of the lab report is:
· to put together all of the data obtained from the experiment
· to analyze the data and to determine the outcome(s) of the experiment
· to connect the data and observations taken in the lab to concepts covered in the class
· to practice or to apply the calculations modeled in the classroom in a lab setting
· to critically review the lab for possible errors, and then to analyze how these possible errors would directly affect the experimental results
· to summarize and present the lab material in a way that a person who has not done the lab could understand your experiment and its results without actually performing it
The following pieces are the components of a full lab report.
You should be familiar with all of these parts and able to perform them for a given lab activity.
· The goal of a pre-lab is to think about how the lab connects to class content. A pre-lab will be assigned before a lab is done in class and will be used to discuss laboratory procedures. This will be checked in prior to beginning the lab activity or a quiz will be given for which you can use your pre-lab.
· Parts of a pre-lab include the following:
a) Title
· Each lab should begin with a title.
b) Purpose
· This should briefly address a couple of main ideas:
o What exactly are you trying to accomplish through the procedures of the lab?
o How will doing this experiment directly relate to the concepts or further my understanding of this concept?
c) SDS
· Look up the SDS information for all chemicals to be used in the lab
· List the pictograms associated with each chemical used
· Make a note by each pictogram explaining why it is specifically referenced – this will be in the wording on the SDS (be specific to the pictogram)
d) Procedure
· Read the steps to the lab and highlight the following:
o Chemicals needed
o Measurements to be made
o Equipment needed
o Specific techniques
· Qualitative data:
o All observations that are easily observed by the senses (sight, sound, feel, smell) should be included. Many times, doing this as before, during, and after may be the easiest, but it can be shown in any form as long as it demonstrates appearance throughout the entire course of the experiment.
· Quantitative data
o These fall into two major categories:
1) Numbers collected in the experiment ~ include any number that was measured or recorded throughout the lab procedures
2) Numbers calculated from data analysis ~ includes the result of all calculations (no matter how simple, i.e. subtraction)
o Multiple data tables can be used if it is more comfortable, but each data table should then have a descriptive title of what is displayed in the table.
· Each calculation used in data analysis should be displayed. You must show your work for ALL calculations and for ALL trials that you complete, even if it is a repeated calculation.
· Colleges expect you to explicitly show your thinking for all problems. Each time you complete a new type of calculation, there should be an explanation in words of why you are doing what you did.
a. Example 1: Mass of precipitate = (mass of filter paper + precipitate) – (mass of filter paper)
1.36 g – 0.46 g = 0.90 grams of precipitate
b. Example 2: Stoichiometry must be used to convert grams of calcium chloride to grams of calcium
carbonate
0.92 g CaCl2 = 0.83 g CaCO3
· Graphs should display all criteria of a good graph (correct title, axes labeled, scale, connected data points or best-fit line where appropriate).
· Along with the graph itself, there should be an explanation of the graph. This short explanation should include the relationship between the variables that the graph is showing and its significance in relation to the chemistry concept that is demonstrated.
· Follow-up questions are designed to have you analyze the experiment and apply the chemistry concepts that were used in the lab. They should be done in complete sentences so that the question is obvious in your response.
o Vocabulary words will be given in a list on most labs. These words should be defined with correct scientific definitions as they would apply to the lab.
· You need to be able to explain how various laboratory errors would affect the final result that you are looking to determine in the lab. In order to do this, you must “MapQuest” the thought process you used to determine this – that is, you must explain how it affects each value in each step leading to the final answer.
· Use RERUN
R Restate the purpose of the activity. Did you achieve your purpose and why?
E Explain the procedure. For example, the Foul Water Lab, the procedure summary might be “physical separation of the oil and water followed by two filtrations are used to purify a sample of foul water
R Real-life. Give one example of how this relates to real life
U Uncertainties. This section discusses error analysis and assumptions. Students are encouraged to be very specific in this section. They should learn not only to identify sources of error but to evaluate how this impacts the final result. DO NOT USE HUMAN ERROR, for example “I used my calculator incorrectly” or “I did the calculations wrong”.
N Two or more NEW things that were learned from performing the activity and how you can apply them to classroom activities
Pictograms Used in SDS