Formal Lab Write-UpsChem 2

1) Lab write-up will be more complex than in Chem 1 and worth more points.

2) Lab reports will be typed. This means that your calculations, data tables, graphs, etc. will all be done on the computer and compiled together for your lab write-up. › There is an equation feature in Word

2007 and a graphing feature (I will show you both)

Your Lab report will be required to have a (in this order)

a. Title: should be described in less than ten words.

b. Purpose/Objective (sometimes several): questions asked or problems posed by the lab› These should be short and to the point

c. Hypotheses: “If… then…” format and must be testable by lab. There should be 1 hypothesis per purpose/objective.› Ex. If the concentration of sodium chloride

in an aqueous solution is increased, then the boiling point of the solution will increase.

d. Data - written in tabular form (if possible), collected in class during the experiment. (no calculations in data tables, only in results tables if applicable)

Data Tables Should be very neat and organized Watch your column and row descriptions

› Should always have type of measurement and then units of measurement in parentheses

Mass of Metal (g)

Volume of Metal (mL)

Trial 1

Trial 2

grams milliliters

Trial 1

Trial 2

THIS NOT THIS

CALCULATIONS Calculations - Describe what is

being calculated in each. Make sure the calculations are done below the description of the calculation. Leave a space between each calculation. › Example:

From Lab: 1) Calculate the mass of the metal before the reaction.

How to put it in your lab write-up 1) Mass of metal before reaction

24.50 g – 14.50 g = 10.00 g

Graphs

All graphs, spreadsheet calculations, or results provided by computer will be printed and glued or taped into the lab write-up. Any calculations done by computer should be described as in any calculation.› Most of your graphs will be created by you

and done in Microsoft Word, we rarely will have a graph to print out and tape in

Questions Questions. These questions must be

answered in complete sentences incorporating the question into your answer.› They should be numbered as they are in the lab› Ex: Explain why the mass of the metal decreased

after the chemical reaction was completed. Incorrect Response: The metal was converted into a new

product. Correct Response: The mass of the metal decreased after the

chemical reaction was completed because the metal went through a chemical change. While going through a chemical change the metal was changed into new products, therefore the mass of the original metal and final product would be different.

Conclusion Conclusion. Should be written in paragraph form.

This section will take the most amount of time and effort. › Explain why you received the data you did. (you do not need

to restate the lab procedure)› Draw inferences. › Be sure to refer back to any data you are discussing. (use this

to back up what you are talking about)› How did your data compare to the other students’ data. › Discuss possible sources of error and what you would do

differently if you were to do the lab again. You MUST ALSO EXPLAIN HOW YOUR ERROR EFFECTED YOUR DATA.

› Restate your hypotheses and accept or reject them each separately. Be sure to back up with your data.

› This should be well organized and flow in a way that makes sense to the reader.

FORMAT

Format: Lab reports should be word processed and double spaced using a normal 12 pt font. Be sure to clearly label all sections. Lab reports should be written in past tense and in third person. Do not use personal pronouns (I, we, they, our, etc….) in your lab report. Make sure to use correct spelling and grammar throughout.

Your lab report is to convey your unique lab experience to the reader in a clear and personal way. It should be well enough written so all information can be easily understood by any other person who reads it. REMEMBER- You want to make sure your report is well enough written, so anyone else looking at it will not misunderstand what you’re trying to say or do.

What is an Inference? Inferences explain why you obtained all the

results you obtained. What is the chemical reason behind the results? This is the part where you apply the information learned in class as an explanation for the results you obtained in the experiment.