Writing a Chemistry Lab Report To be done BEFORE lab Title On the top of the lab page you will record Title of Lab Source (Where did the lab come from?) Partner Name Date (and sometimes time) Purpose Write one or two sentences that describe the reasons or objectives for completing the lab. This is where your hypothesis will be written if the lab requires one. List of Materials Include a list of materials needed to complete the experiment. This list is not for you alone. It is for everyone who will try to repeat your amazing discoveries after the fact. So include everything. (water, safety equipment, …) Safety Considerations List applicable safety rules to consider in this experiment. Include special handling and disposal instructions. Leave room to add new thing that occurred during the lab. Procedure In your own words, write the directions for the experiment in a numbered step-by-step list For pre-designed labs (most if not all in Chemistry 11) the procedure will be very similar to the one in the handout. Make it so that you can understand it, but don’t lose too much scientific vocabulary Data Table(s) Create a blank data table to record data collected during the experiment Record the information from the experiment in the table while conducting the lab Include units for all measurements. Never erase recorded data simply draw a single line through a mistake and record the new value next to it. Observations Create a blank table (space) to record observations collected during the experiment Include anything you see, smell, hear, etc. Record what your senses tell you not what your brain tells you. Cooper fell to the bottom of the beaker X A reddish solid fell to the bottom of the beaker √ To be done AFTER lab Calculations/Results Include all pertinent calculations. For all calculations, the equation must be expressed in words first before numbers are used in the equation. Example: mass / molar mass = number of moles 48.0g / 16.00 g/mol = 3.00 mol If a certain type of calculate is done over and over again. Do one in full followed by the others Show work for calculations, express all answers to the correct number of significant digits and include units. Percent error Calculate difference 1:1.3 compared to 1:1 1.3 – 1 = 0.3 Calculate % - Always difference ÷ Theoretical 0.3 ÷ 1 = 0.3 = 30% Discussion This is where the discussion of the lab is placed (Answers to discussion questions). Must be in complete sentences Conclusion Was the purpose of the lab met? How does what happened correspond to theoretical values? (Identify any errors made that may have contributed to your data not corresponding to theoretical values. Discuss improvements that could be made.) How does this experiment connect to what you have learned in class (theory)? Example Conclusion The purpose of this lab was met because using a reaction of … were able to be calculated. The mole ratio calculated from the data was 1:1.3. The theoretical value is 1:1. Giving a percent error of 30% which is substantial. This error could have arose due to 1… 2… 3…. We could improve next time by 1… 2… 3…. The reaction CuCl2(aq) + Fe(s) Cu(s) + FeCl2(aq) is a single replacement reaction which is a topic reviewed in class. To find the number of moles of iron and copper we used concepts from molar theory (learned in class) including using molar mass to relate mass and number of moles.